Eclipsed4utoo's Blog» WP7

WP7 – Using IsolatedStorageSettings

Ryan Alford — Sun, 14 Aug 2011 23:00:07 +0000

In a previous tutorial, I wrote about using the Isolated Storage to store files on a WP7 device. Let’s say that instead of storing data, you wanted to store settings for your application. This where the IsolatedStorageSettings comes in.

The IsolatedStorageSettings is a place to store Key/Value pairs of data.

So let’s say that my application used the Microsoft Ad control, but I wanted to be nice and give the user the ability to turn the ads on and off.

On my Settings screen, I would have a checkbox(AdsCheckbox) for allowing the ads. In code, I would save the value by doing this…

var settings = IsolatedStorageSettings.ApplicationSettings;

if (settings.Contains("AllowAds"))
    settings["AllowAds"] = AdsCheckbox.IsChecked.Value;
else
    settings.Add("AllowAds", AdsCheckbox.IsChecked.Value);

settings.Save();

If you will notice, the ApplicationSettings object does have a method that allows you to check to see if the key already exists in the Settings. An exception will be thrown if you try to add a key that already exists, so it’s necessary to do this check before assigning a value.

Also, as you can see, it’s very easy to get the value out of the settings…

// when the form opens, I want to set the Checkbox to being checked
//   or unchecked depending on the setting
var settings = IsolatedStorageSettings.ApplicationSettings;

if (settings.Contains("AllowAds"))
    AdsCheckbox.IsChecked = bool.Parse(settings["AllowAds"].ToString());

However, the IsolatedStorageSettings class isn’t only for simply datatypes. It can also store your custom class objects.

Employee class

public class Employee
{
    public string FullName { get; set; }
    public decimal Salary { get; set; }
}

Then on my form, I have a button to save an instance of the Employee class to the IsolatedStorageSettings…

private void btnSave_Click(object sender, RoutedEventArgs e)
{
    var settings = IsolatedStorageSettings.ApplicationSettings;

    Employee emp = new Employee()
    {
        FullName = "John Doe",
        Salary = 250000
    };

    settings.Add("Employee1", emp);
    settings.Save();
}

I also have a button that will load the object from the IsolatedStorageSettings…

private void btnLoad_Click(object sender, RoutedEventArgs e)
{
    var settings = IsolatedStorageSettings.ApplicationSettings;

    Employee emp;

    if (settings.TryGetValue("Employee1", out emp))
    {
         MessageBox.Show(string.Format("Full Name: {0}\nSalary: {1:c}", emp.FullName, emp.Salary));
    }
}

Notice that the IsolatedStorageSettings.ApplicationSettings class also has the TryGetValue method. This method behaves exactly like the TryParse methods of the .Net datatypes. It will return a boolean specifying whether the key was found and whether the conversion from object –> Employee was successful. If it’s successful, it will return the instance as the out parameter.

After running the application, clicking the Save button, then clicking the Load button, we will get this message box…

WP7 – Working With Isolated Storage

Ryan Alford — Thu, 11 Aug 2011 23:00:28 +0000

In this tutorial, I will demonstrate how to work with Isolated Storage in Windows Phone 7. This is going to be a very simple tutorial where we create a text file and write data to it. We will then read that data and append more data to it.

So first, we need to add these using statements to the top of the code(if they aren’t already there):

using System.IO;
using System.IO.IsolatedStorage;
using System.Windows;

Next we will have our form. Very basic. It has two Textboxes and a Button. The first TextBox will allow the user to type in some text. The Button will save the data to IsolatedStorage, then read the data from the file and put it into the second TextBox.

Here is the XAML:

So now we move to the code. We need to create an IsolatedStorageFile object:

using (var isoStorage = IsolatedStorageFile.GetUserStoreForApplication())
{

}

Since we will always be appending to the file, we need to check to make sure the file exists. If it doesn’t exist, we need to create it.

// we need to check to see if the file exists
if (!isoStorage.FileExists(fileName))
{
    // file doesn't exist...time to create it.
    isoStorage.CreateFile(fileName);
}

Once we have done the FileExists check, we can now open the file. Once the file has been opened, we can now use the StreamWriter class to write to it.

// since we are appending to the file, we must use FileMode.Append
using (var isoStream = new IsolatedStorageFileStream(fileName, FileMode.Append, isoStorage))
{
    // opens the file and writes to it.
    using (var fileStream = new StreamWriter(isoStream))
    {
        fileStream.WriteLine(txtText.Text);
    }
}

Note: notice that we opened the file using FileMode.Append. Because we used this mode, we can’t read from the file, we can only write to it.

So to read from the file, we will need to open the file again, this time using FileMode.Open. We are going to do this in another using block. Once the file is opened, we use the StreamReader class to read it.

// you cannot read from a stream that you opened in FileMode.Append.  Therefore, we need
//   to close the IsolatedStorageFileStream then open it again in a different FileMode.  Since we
//   we are simply reading the file, we use FileMode.Open
using (var isoStream = new IsolatedStorageFileStream(fileName, FileMode.Open, isoStorage))
{
    // opens the file and reads it.
    using (var fileStream = new StreamReader(isoStream))
    {
        txtCurrentText.Text = fileStream.ReadToEnd();
    }
}

And that’s it. If you run the application, type in the first textbox, hit Save, the data will show up in the bottom textbox. Do it again, and you will see that it has appended to the file.

As you can see, writing to Isolated Storage is really easy.

Here is the entire code for the form…

using System.IO;
using System.IO.IsolatedStorage;
using System.Windows;
using Microsoft.Phone.Controls;

namespace WP7IsoStorageDemo
{
    public partial class MainPage : PhoneApplicationPage
    {
        // Constructor
        public MainPage()
        {
            InitializeComponent();
        }

        private void btnSave_Click(object sender, RoutedEventArgs e)
        {
            string fileName = "MyTextfile.txt";

            using (var isoStorage = IsolatedStorageFile.GetUserStoreForApplication())
            {
                // we need to check to see if the file exists
                if (!isoStorage.FileExists(fileName))
                {
                    // file doesn't exist...time to create it.
                    isoStorage.CreateFile(fileName);
                }

                // since we are appending to the file, we must use FileMode.Append
                using (var isoStream = new IsolatedStorageFileStream(fileName, FileMode.Append, isoStorage))
                {
                    // opens the file and writes to it.
                    using (var fileStream = new StreamWriter(isoStream))
                    {
                        fileStream.WriteLine(txtText.Text);
                    }
                }

                // you cannot read from a stream that you opened in FileMode.Append.  Therefore, we need
                //   to close the IsolatedStorageFileStream then open it again in a different FileMode.  Since we
                //   we are simply reading the file, we use FileMode.Open
                using (var isoStream = new IsolatedStorageFileStream(fileName, FileMode.Open, isoStorage))
                {
                    // opens the file and reads it.
                    using (var fileStream = new StreamReader(isoStream))
                    {
                        txtCurrentText.Text = fileStream.ReadToEnd();
                    }
                }
            }
        }
    }
}

WP7 – Using the ToggleSwitch

Ryan Alford — Wed, 17 Nov 2010 15:00:55 +0000

This will be the first of a number of posts highlighting the new controls that have been added to the WP7 Toolkit. It’s a really great set of tools that makes life easier for us developers.

Download WP7 Toolkit

So the first control I am going to talk about is the ToggleSwitch control. It’s a control that resembles a lightswitch and is a nice was of showing an On/Off or True/False setting instead of using a plain checkbox.

So let’s create a Windows Phone 7 project called ToggleSwitchDemo.

Open the Toolbox and find the ToggleSwitch control. If it’s not listed, right-click on the Toolbox –> Choose Items –> then scroll down until you find the ToggleSwitch control in the list.

Once the control is in the Toolbox, drag it onto the page. By default, it will look like this….

Run the application using F5, then click on the ToggleSwitch. It will change from Off to On.

There are a number of options that are available for the text for the ToggleControl. The Header property will change the heading of the control. The Content property will set the content of the control(On/Off).

In one of my application, I used the ToggleSwitch to allow the user to turn on/off Ads that I have in the app. So for me, I changed the Header to “Ads”, and since I default the ToggleSwitch to being On(IsChecked is True), I set the Content to “Ads are enabled“.

The ToggleSwitch also allows you to handle when the control is checked and unchecked. So here is how my ToggleSwitch would look in XAML…

Then the code for the Checked and Unchecked events…

private void AdsToggleSwitch_Checked(object sender, RoutedEventArgs e)
{
     AdsToggleSwitch.Content = "Ads are enabled";
}

private void AdsToggleSwitch_Unchecked(object sender, RoutedEventArgs e)
{
     AdsToggleSwitch.Content = "Ads are disabled";
}

Now my control would look like this…

The ToggleSwitch is a great control that allows your app to keep the “Metro” look and feel that a plain CheckBox wouldn’t allow you to do without custom coding.

WP7 – Using the Microsoft AdControl

Ryan Alford — Mon, 15 Nov 2010 17:00:23 +0000

For the Windows Phone 7 platform, Microsoft decided to roll-out it’s own mobile ad service. This service is Microsoft Advertising PubCenter. Along with the service, they also added a custom control that we developers can add to our Windows Phone 7 applications.

First, we will need to download the Advertising SDK. That can be done from here. After downloading, install it as you would any other .msi, but you will want to note the install directory. On Windows 7 64-bit, the install directory will be “C:\Program Files (x86)\Microsoft Advertising SDK for Windows Phone 7“.

So first, you will need to go to the PubCenter, create an account(which is free). Once your account is created, login, then go to the Setup tab. From here, you will want to register your mobile application and create an application ad unit. It may take some time for the Ad Unit or application to be approved, so we are allowed to use some testing values for development purposes.

You will want to note the application ID and the Ad Unit ID. We will need both of these.

So let’s create a new WP7 project. I just created a simple project and named it AdControlDemo.

Once the project has been created, open the Toolbox. We are going to add a new tab for the AdControl. Right-click somewhere in the Toolbox, then choose Add Tab.

I gave my tab the name Advertising Control.

Now right-click in the new Tab area, and click Choose Items.

When the Choose Items dialog comes up, click the Browse button.

Navigate to the install directory of the Advertising SDK that was installed. You will want to add the Microsoft.Advertising.Mobile.UI.dll file.

You will now see that the AdControl has been added to our list of items. Now click OK.

Now the AdControl has been added to our Toolbox.

Now we are going to simply drag the control onto our screen. Now open the Properties window, and you will see two properties for the AdUnitId and the ApplicationId. For testing purposes, you can use “test_client” as the ApplicationId and “TextAd” as the AdUnitId.

So let’s run our application in the emulator by hitting F5, and you will see test ads showing up.

Now, once you setup your own application and ad unit and replaced the test values with your values, you will need to add this code to one of the initialization methods in the App.cs. I put it at the bottom of the constructor.

Microsoft.Advertising.Mobile.UI.AdControl.TestMode = false;

Without this code, the control will not show on the screen.

You now have advertising in your WP7 application.

WP7 – Context Menu From Listbox

Ryan Alford — Thu, 26 Aug 2010 11:58:40 +0000

In writing one of my Windows Phone 7 applications, I needed to do a allow the user to delete an entry from a ListBox. Since my ListBox didn’t have enough room for an actual delete button, I decided I would use a ContextMenu to do it. To my surprise, even though the OS seems to support a long press action(the way to uninstall an application), that action doesn’t seem to be available to developers(or not that I could find). So I decided to roll my own using the [b]MouseLeftButtonDown [/b]and [b]MouseLeftButtonUp [/b]events, and a [b]DispatcherTimer[/b]. Add these two using statements to the top of the code…

 using System.Collections.ObjectModel; using System.Windows.Threading;

So first, we need our initial code to get the [b]ListBox [/b]populated. I created a [b]Person [/b]class just for simplistic reasons.

 public class Person {     public string FirstName { get; set; }     public string LastName { get; set; } }

Next, I will set up the [b]ListBox [/b]to simply show the [b]FirstName [/b]of the [b]Person[/b].

Now I will create an generic [b]ObservableCollection [/b]object to store the [b]Person [/b]objects. This will be a class level variable since it will be accessed from multiple events.

 public partial class MainPage : PhoneApplicationPage {     ObservableCollection personList = new ObservableCollection();      // Constructor     public MainPage()     {         InitializeComponent();          this.Loaded += new RoutedEventHandler(MainPage_Loaded);     }      void MainPage_Loaded(object sender, RoutedEventArgs e)     {         personList.Add(new Person() { FirstName = "John", LastName = "Doe" });         personList.Add(new Person() { FirstName = "Jane", LastName = "Doe" });         personList.Add(new Person() { FirstName = "John", LastName = "Adams" });          lbNames.ItemsSource = personList;     } }

Now I need to create the event handlers for the [b]MouseLeftButtonDown [/b]and [b]MouseLeftButtonUp [/b]events. This can simply be done by using the [b]Events [/b]list from the [b]Properties [/b]window in the designer.

 private void lbNames_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e) {  }  private void lbNames_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e) {  }

We now need to create two class level objects: a [b]DispatcherTimer [/b]object, and a [b]Person [/b]object. These are class level because they will need to be accessed from different events. We will also subscribe to the Tick event for the timer.

 ObservableCollection personList = new ObservableCollection();  DispatcherTimer timer;  Person selectedPerson = null;  // Constructor public MainPage() {     InitializeComponent();      this.Loaded += new RoutedEventHandler(MainPage_Loaded);      timer = new DispatcherTimer();     timer.Tick += delegate(object s, EventArgs e)     {      }; }

Next, we will add a [b]Popup [/b]in XAML. This can go above or below the [b]ListBox[/b] that is currently holding the names.

And the event handler for selecting the Delete item…

 private void DeleteContextMenu_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e) {  }

Here is how it’s going to work. When the user presses down, we will start the timer. When the user releases, then we stop the timer. So if the timer’s interval is reached, we know that the user was holding down on the screen, so we will display the popup. So now we move to our code. First we are going to handle the [b]MouseLeftButtonDown [/b]event.

 private void lbNames_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e) {     // if there is no person selected, then there is no person to delete     //   no need to do any code if nothing is selected     if (selectedPerson == null)         return;      // gets the position of the mouse cursor to set the Margin     //    of the Popup to show at the mouse coordinates.  You     //    may need to tweak these values to get it to display in     //    the correct location.     Point position = e.GetPosition((UIElement)this);     DeleteContextMenu.Margin = new Thickness(position.X, position.Y - 200, 20, 0);      // sets the interval to 1.1 seconds.  This means the user will need      //    to hold down on the screen for 1.1 seconds before we determine     //    to show the ContextMenu.     timer.Interval = TimeSpan.FromMilliseconds(1100);     timer.Start(); }

Next, we will do our code for the [b]MouseLeftButtonUp[/b] event

 private void lbNames_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e) {     // stop the timer when the user releases the screen     timer.Stop();      // sets the class level variable to the selected row     selectedPerson = lbNames.SelectedItem as Person; }

Now for our code in the [b]Tick [/b]event for the [b]Timer[/b].

 // Constructor public MainPage() {     InitializeComponent();      this.Loaded += new RoutedEventHandler(MainPage_Loaded);      timer = new DispatcherTimer();     timer.Tick += delegate(object s, EventArgs e)     {         // stop the timer so that it doesn't popup the Context menu again         timer.Stop();          // since we are using the same ListBox over and over, this will         //   make it so when the Context Menu is shown, there will be no         //   selected item from any previous showing of the Context Menu         lbDeleteContextMenu.SelectedIndex = -1;          // opens the Context Menu         DeleteContextMenu.IsOpen = true;     }; }

Last, we have our code from the [b]SelectionChanged [/b]event for the [b]ListBox [/b]that is part of the Context Menu.

 private void DeleteContextMenu_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e) {     // in the Timer's Tick event, we set the SelectedIndex of the     //   Context Menu's Listbox back to -1.  However, this does     //   fire the SelectionChanged event.  This code will handle that.     if (lbDeleteContextMenu.SelectedIndex == -1)         return;      // closes the Context Menu     DeleteContextMenu.IsOpen = false;      if (selectedPerson == null)         return;      // removes the selected person from the list     personList.Remove(selectedPerson);      // since we are using an ObservableCollection, we do not have     //   to rebind the list to the ListBox.      selectedPerson = null; }

Now you can run the application, and you will see the list show up. You must click on an item first before clicking and holding to show the Context Menu.

So I decided to roll my own using the [b]MouseLeftButtonDown [/b]and [b]MouseLeftButtonUp [/b]events, and a [b]DispatcherTimer[/b].

Add these two using statements to the top of the code…

using System.Collections.ObjectModel;

using System.Windows.Threading;

So first, we need our initial code to get the [b]ListBox [/b]populated. I created a [b]Person [/b]class just for simplistic reasons.

public class Person

{

public string FirstName { get; set; }

public string LastName { get; set; }

}

Next, I will set up the [b]ListBox [/b]to simply show the [b]FirstName [/b]of the [b]Person[/b].

Name="lbNames"

Height="240"

HorizontalAlignment="Left"

Margin="10,119,0,0"

VerticalAlignment="Top"

Width="460"

ItemsSource="{Binding}">

Now I will create an generic [b]ObservableCollection [/b]object to store the [b]Person [/b]objects. This will be a class level variable since it will be accessed from multiple events.

public partial class MainPage : PhoneApplicationPage

{

ObservableCollection personList = new ObservableCollection();

// Constructor

public MainPage()

{

InitializeComponent();

this.Loaded += new RoutedEventHandler(MainPage_Loaded);

}

void MainPage_Loaded(object sender, RoutedEventArgs e)

{

personList.Add(new Person() { FirstName = "John", LastName = "Doe" });

personList.Add(new Person() { FirstName = "Jane", LastName = "Doe" });

personList.Add(new Person() { FirstName = "John", LastName = "Adams" });

lbNames.ItemsSource = personList;

}

private void lbNames_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)

{

}

private void lbNames_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)

{

}

ObservableCollection personList = new ObservableCollection();

DispatcherTimer timer;

Person selectedPerson = null;

// Constructor

public MainPage()

{

InitializeComponent();

this.Loaded += new RoutedEventHandler(MainPage_Loaded);

timer = new DispatcherTimer();

timer.Tick += delegate(object s, EventArgs e)

{

};

}

Next, we will add a [b]Popup [/b]in XAML. This can go above or below the [b]ListBox[/b] that is currently holding the names.

x:Name="DeleteContextMenu"

Height="200"

Width="400">

x:Name="lbDeleteContextMenu"

Background="White"

SelectionChanged="DeleteContextMenu_SelectionChanged">

Content="Delete Person"

Foreground="Red"

FontSize="25"

FontWeight="Bold"/>

And the event handler for selecting the Delete item…

private void DeleteContextMenu_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)

{

}

So now we move to our code. First we are going to handle the [b]MouseLeftButtonDown [/b]event.

private void lbNames_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)

{

// if there is no person selected, then there is no person to delete

// no need to do any code if nothing is selected

if (selectedPerson == null)

return;

// gets the position of the mouse cursor to set the Margin

// of the Popup to show at the mouse coordinates. You

// may need to tweak these values to get it to display in

// the correct location.

Point position = e.GetPosition((UIElement)this);

DeleteContextMenu.Margin = new Thickness(position.X, position.Y - 200, 20, 0);

// sets the interval to 1.1 seconds. This means the user will need

// to hold down on the screen for 1.1 seconds before we determine

// to show the ContextMenu.

timer.Interval = TimeSpan.FromMilliseconds(1100);

timer.Start();

}

Next, we will do our code for the [b]MouseLeftButtonUp[/b] event

private void lbNames_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)

{

// stop the timer when the user releases the screen

timer.Stop();

// sets the class level variable to the selected row

selectedPerson = lbNames.SelectedItem as Person;

}

Now for our code in the [b]Tick [/b]event for the [b]Timer[/b].

// Constructor

public MainPage()

{

InitializeComponent();

this.Loaded += new RoutedEventHandler(MainPage_Loaded);

timer = new DispatcherTimer();

timer.Tick += delegate(object s, EventArgs e)

{

// stop the timer so that it doesn't popup the Context menu again

timer.Stop();

// since we are using the same ListBox over and over, this will

// make it so when the Context Menu is shown, there will be no

// selected item from any previous showing of the Context Menu

lbDeleteContextMenu.SelectedIndex = -1;

// opens the Context Menu

DeleteContextMenu.IsOpen = true;

};

}

Last, we have our code from the [b]SelectionChanged [/b]event for the [b]ListBox [/b]that is part of the Context Menu.

private void DeleteContextMenu_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)

{

// in the Timer's Tick event, we set the SelectedIndex of the

// Context Menu's Listbox back to -1. However, this does

// fire the SelectionChanged event. This code will handle that.

if (lbDeleteContextMenu.SelectedIndex == -1)

return;

// closes the Context Menu

DeleteContextMenu.IsOpen = false;

if (selectedPerson == null)

return;

// removes the selected person from the list

personList.Remove(selectedPerson);

// since we are using an ObservableCollection, we do not have

// to rebind the list to the ListBox.

selectedPerson = null;

}

Now you can run the application, and you will see the list show up. You must click on an item first before clicking and holding to show the Context Menu.

So I decided to roll my own using the [b]MouseLeftButtonDown [/b]and [b]MouseLeftButtonUp [/b]events, and a [b]DispatcherTimer[/b].

Add these two using statements to the top of the code…

using System.Collections.ObjectModel;

using System.Windows.Threading;

So first, we need our initial code to get the [b]ListBox [/b]populated. I created a [b]Person [/b]class just for simplistic reasons.

public class Person

{

public string FirstName { get; set; }

public string LastName { get; set; }

}

Next, I will set up the [b]ListBox [/b]to simply show the [b]FirstName [/b]of the [b]Person[/b].

Name="lbNames"

Height="240"

HorizontalAlignment="Left"

Margin="10,119,0,0"

VerticalAlignment="Top"

Width="460"

ItemsSource="{Binding}">

Now I will create an generic [b]ObservableCollection [/b]object to store the [b]Person [/b]objects. This will be a class level variable since it will be accessed from multiple events.

public partial class MainPage : PhoneApplicationPage

{

ObservableCollection personList = new ObservableCollection();

// Constructor

public MainPage()

{

InitializeComponent();

this.Loaded += new RoutedEventHandler(MainPage_Loaded);

}

void MainPage_Loaded(object sender, RoutedEventArgs e)

{

personList.Add(new Person() { FirstName = "John", LastName = "Doe" });

personList.Add(new Person() { FirstName = "Jane", LastName = "Doe" });

personList.Add(new Person() { FirstName = "John", LastName = "Adams" });

lbNames.ItemsSource = personList;

}

private void lbNames_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)

{

}

private void lbNames_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)

{

}

ObservableCollection personList = new ObservableCollection();

DispatcherTimer timer;

Person selectedPerson = null;

// Constructor

public MainPage()

{

InitializeComponent();

this.Loaded += new RoutedEventHandler(MainPage_Loaded);

timer = new DispatcherTimer();

timer.Tick += delegate(object s, EventArgs e)

{

};

}

Next, we will add a [b]Popup [/b]in XAML. This can go above or below the [b]ListBox[/b] that is currently holding the names.

x:Name="DeleteContextMenu"

Height="200"

Width="400">

x:Name="lbDeleteContextMenu"

Background="White"

SelectionChanged="DeleteContextMenu_SelectionChanged">

Content="Delete Person"

Foreground="Red"

FontSize="25"

FontWeight="Bold"/>

And the event handler for selecting the Delete item…

private void DeleteContextMenu_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)

{

}

So now we move to our code. First we are going to handle the [b]MouseLeftButtonDown [/b]event.

private void lbNames_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)

{

// if there is no person selected, then there is no person to delete

// no need to do any code if nothing is selected

if (selectedPerson == null)

return;

// gets the position of the mouse cursor to set the Margin

// of the Popup to show at the mouse coordinates. You

// may need to tweak these values to get it to display in

// the correct location.

Point position = e.GetPosition((UIElement)this);

DeleteContextMenu.Margin = new Thickness(position.X, position.Y - 200, 20, 0);

// sets the interval to 1.1 seconds. This means the user will need

// to hold down on the screen for 1.1 seconds before we determine

// to show the ContextMenu.

timer.Interval = TimeSpan.FromMilliseconds(1100);

timer.Start();

}

Next, we will do our code for the [b]MouseLeftButtonUp[/b] event

private void lbNames_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)

{

// stop the timer when the user releases the screen

timer.Stop();

// sets the class level variable to the selected row

selectedPerson = lbNames.SelectedItem as Person;

}

Now for our code in the [b]Tick [/b]event for the [b]Timer[/b].

// Constructor

public MainPage()

{

InitializeComponent();

this.Loaded += new RoutedEventHandler(MainPage_Loaded);

timer = new DispatcherTimer();

timer.Tick += delegate(object s, EventArgs e)

{

// stop the timer so that it doesn't popup the Context menu again

timer.Stop();

// since we are using the same ListBox over and over, this will

// make it so when the Context Menu is shown, there will be no

// selected item from any previous showing of the Context Menu

lbDeleteContextMenu.SelectedIndex = -1;

// opens the Context Menu

DeleteContextMenu.IsOpen = true;

};

}

Last, we have our code from the [b]SelectionChanged [/b]event for the [b]ListBox [/b]that is part of the Context Menu.

private void DeleteContextMenu_SelectionChanged(object sender, System.Windows.Controls.SelectionChangedEventArgs e)

{

// in the Timer's Tick event, we set the SelectedIndex of the

// Context Menu's Listbox back to -1. However, this does

// fire the SelectionChanged event. This code will handle that.

if (lbDeleteContextMenu.SelectedIndex == -1)

return;

// closes the Context Menu

DeleteContextMenu.IsOpen = false;

if (selectedPerson == null)

return;

// removes the selected person from the list

personList.Remove(selectedPerson);

// since we are using an ObservableCollection, we do not have

// to rebind the list to the ListBox.

selectedPerson = null;

}

Now you can run the application, and you will see the list show up. You must click on an item first before clicking and holding to show the Context Menu.

To my surprise, even though the OS seems to support a long press action(the way to uninstall an application), that action doesn’t seem to be available to developers(or not that I could find).

So I decided to roll my own using the MouseLeftButtonDown and MouseLeftButtonUp events, and a DispatcherTimer.

Add these two using statements to the top of the code…

using System.Collections.ObjectModel;
using System.Windows.Threading;

So first, we need our initial code to get the ListBox populated. I created a Person class just for simplistic reasons.

public class Person
{
     public string FirstName { get; set; }
     public string LastName { get; set; }
}

Next, I will set up the ListBox to simply show the FirstName of the Person.

Now I will create an generic ObservableCollection object to store the Person objects. This will be a class level variable since it will be accessed from multiple events.

public partial class MainPage : PhoneApplicationPage
{
    ObservableCollection personList = new ObservableCollection();

    // Constructor
    public MainPage()
    {
        InitializeComponent();

        this.Loaded += new RoutedEventHandler(MainPage_Loaded);
    }

    void MainPage_Loaded(object sender, RoutedEventArgs e)
    {
        personList.Add(new Person() { FirstName = "John", LastName = "Doe" });
        personList.Add(new Person() { FirstName = "Jane", LastName = "Doe" });
        personList.Add(new Person() { FirstName = "John", LastName = "Adams" });

        lbNames.ItemsSource = personList;
    }
}

Now I need to create the event handlers for the MouseLeftButtonDown and MouseLeftButtonUp events. This can simply be done by using the Events list from the Properties window in the designer.

private void lbNames_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{

}

private void lbNames_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{

}

We now need to create two class level objects: a DispatcherTimer object, and a Person object. These are class level because they will need to be accessed from different events. We will also subscribe to the Tick event for the timer.

ObservableCollection personList = new ObservableCollection();

DispatcherTimer timer;

Person selectedPerson = null;

// Constructor
public MainPage()
{
    InitializeComponent();

    this.Loaded += new RoutedEventHandler(MainPage_Loaded);

    timer = new DispatcherTimer();
    timer.Tick += delegate(object s, EventArgs e)
    {

    };
}

Next, we will add a Popup in XAML. This can go above or below the ListBox that is currently holding the names.

And the event handler for selecting the Delete item…

private void DeleteContextMenu_Selectionchanged(object sender, System.Windows.Controls.SelectionchangedEventArgs e)
{

}

So now we move to our code. First we are going to handle the MouseLeftButtonDown event.

private void lbNames_MouseLeftButtonDown(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
    // if there is no person selected, then there is no person to delete
    //   no need to do any code if nothing is selected
    if (selectedPerson == null)
        return;

    // gets the position of the mouse cursor to set the Margin
    //    of the Popup to show at the mouse coordinates.  You
    //    may need to tweak these values to get it to display in
    //    the correct location.
    Point position = e.GetPosition((UIElement)this);
    DeleteContextMenu.Margin = new Thickness(position.X, position.Y - 200, 20, 0);

    // sets the interval to 1.1 seconds.  This means the user will need
    //    to hold down on the screen for 1.1 seconds before we determine
    //    to show the ContextMenu.
    timer.Interval = TimeSpan.FromMilliseconds(1100);
    timer.Start();
}

Next, we will do our code for the MouseLeftButtonUp event

private void lbNames_MouseLeftButtonUp(object sender, System.Windows.Input.MouseButtonEventArgs e)
{
    // stop the timer when the user releases the screen
    timer.Stop();

    // sets the class level variable to the selected row
    selectedPerson = lbNames.SelectedItem as Person;
}

Now for our code in the Tick event for the Timer.

// Constructor
public MainPage()
{
    InitializeComponent();

    this.Loaded += new RoutedEventHandler(MainPage_Loaded);

    timer = new DispatcherTimer();
    timer.Tick += delegate(object s, EventArgs e)
    {
        // stop the timer so that it doesn't popup the Context menu again
        timer.Stop();

        // since we are using the same ListBox over and over, this will
        //   make it so when the Context Menu is shown, there will be no
        //   selected item from any previous showing of the Context Menu
        lbDeleteContextMenu.SelectedIndex = -1;

        // opens the Context Menu
        DeleteContextMenu.IsOpen = true;
    };
}

Last, we have our code from the SelectionChanged event for the ListBox that is part of the Context Menu.

private void DeleteContextMenu_Selectionchanged(object sender, System.Windows.Controls.SelectionchangedEventArgs e)
{
    // in the Timer's Tick event, we set the SelectedIndex of the
    //   Context Menu's Listbox back to -1.  However, this does
    //   fire the Selectionchanged event.  This code will handle that.
    if (lbDeleteContextMenu.SelectedIndex == -1)
        return;

    // closes the Context Menu
    DeleteContextMenu.IsOpen = false;

    if (selectedPerson == null)
        return;

    // removes the selected person from the list
    personList.Remove(selectedPerson);

    // since we are using an ObservableCollection, we do not have
    //   to rebind the list to the ListBox.

    selectedPerson = null;
}

Now you can run the application, and you will see the list show up. You must click on an item first before clicking and holding to show the Context Menu.

WCF RIA Services – Error When Moving Service To Server

Ryan Alford — Thu, 01 Jul 2010 21:40:45 +0000

I recently tried publishing a WCF RIA Service to my server, and came across an error. I was using all the latest Windows Phone 7 and RIA Services Tools, and targeting the .Net 4 framework. However, since I have both .Net 3.5 and .Net 4 installed on my server, I ran into this error…

“System.Configuration.ConfigurationErrorsException: The value for the ‘compilerVersion’ attribute in the provider options must be ‘v4.0′ or later if you are compiling for version 4.0 or later of the .NET Framework. To compile this Web application for version 3.5 or earlier of the .NET Framework, remove the ‘targetFramework’ attribute from the element of the Web.config file.”

It threw me for a loop because it worked fine in Visual Studio 2010 when testing on my development PC, but when moving it to the server, it had this problem.

The fix was fairly easy, once I was able to find it. Basically, you need to add the a section to the web.config that doesn’t get added when adding the RIA Services DomainService to the project.