Silverlight 5 : Implement “Run” functionality using Platform Invoke (PInvoke)

 

I hope you like my last article on PInvoke feature introduced in Silverlight 5 RC. As I mentioned in my last post that I will be posting more and more advance demos of PInvoke in coming days.Well, Today I am going to show you that how you can build “Run” kind of functionality using PInvoke in Silverlight 5 RC,Not getting this idea? Here is “Run” in our Windows look like :

Something similar we are going to develop using PInvoke in terms of look and feel and functionality.Idea is to make use of Shell32.dll’s ShellExecute( ).

I kept UI similar to Windows “Run” for better understanding,It is not exact replica or replacement for Windows “Run”, Idea is to demonstrate the functionality of ShellExecute( ) so I am not trying to break any copyright stuff of original Windows OS.

As discussed in my last article here,following the same steps lets build this component.

Namespace :

using System.Runtime.InteropServices;

This is the primary namespace used to develop PInvoke apps.

XAML :

<Image Source="Run.jpg" Height="42" Width="46" Canvas.Left="0" Canvas.Top="11" />
            <TextBlock Text="Type the name of Program,Folder,document,or Internet resource and Windows will open it for you." TextAlignment="Left" Height="44" Width="319" TextWrapping="Wrap" Canvas.Left="50" Canvas.Top="8" />
            <TextBlock Text="Open:" Height="20" Width="46" Canvas.Top="62" Canvas.Left="6" />
            <TextBox Height="23" HorizontalAlignment="Left" x:Name="txtValue" Width="311" Canvas.Left="50" Canvas.Top="62" />
            <Button x:Name="btnSubmit" Click="btnSubmit_Click" Content="Ok" Width="76" Height="22" Canvas.Left="50" Canvas.Top="100" d:LayoutOverrides="VerticalAlignment" />
            <Button x:Name="btnCancel" Click="btnCancel_Click"  Content="Cancel" Width="76" Height="22" Canvas.Left="150" Canvas.Top="100" d:LayoutOverrides="VerticalAlignment, Width" />

Note that like in Real “Run” box, I am skipping editable dropdown control and Browse button,Here I am taking Textbox to enter parameters and Ok and Cancel Button to handle the same.

UI will look like this after running :

C# Code :

public MainPage()
{
      InitializeComponent();
      App.Current.MainWindow.Title = "Run";            
}    

#region Shell Execute

[DllImport("shell32.dll")]
static extern IntPtr ShellExecute(
            IntPtr hwnd,
            string lpOperation,
            string lpFile,
            string lpParameters,
            string lpDirectory,
            ShowCommands nShowCmd);

#endregion     

private void btnSubmit_Click(object sender, RoutedEventArgs e)
       {
           ShellExecute(System.IntPtr.Zero, "open", Convert.ToString(txtValue.Text), string.Empty, string.Empty, ShowCommands.SW_SHOWNOACTIVATE);
       }

       private void btnCancel_Click(object sender, RoutedEventArgs e)
       {
           if (App.Current.IsRunningOutOfBrowser)
               App.Current.MainWindow.Close();
       }

Note that you need to build ShowCommands enum, for more information you can visit ShellExecute Documentation on MSDN here

txtValue does the job of taking parameters and passing to ShellExecute.

That’s it ! We are done with our own “Run” box build using Silverlight 5 RC P/Invoke Feature using Shell32.dll ‘s ShellExecute( )

OOB Settings :

Kindly refer my last post where I have given all information about setting trust and what kind of possible exceptions you might get.So read more over there.

Output :

Here are some screenshots I took with our Silverlight 5 based “Run” :

Calling Calculator,Command Prompt and MS Paint from our “Run” box

Visit my blog / any URL using our “Run” box ":

So if we compare Windows’s Run box and our in terms of looks..here we go !

Where this can be applicable in Real life applications ? :

Idea in this demo is to use ShellExecute( ) in Silverlight application,UI can be different or in different formatting.Core idea is to use ShellExecute( ) and make use of that using P/Invoke, Do you want me to share what can be done with ShellExecute( ) ? I know I don’t need to..there are lot of business scenarios where this can be used,For example : Open instances of Word,Excel,Powerpoint,MS Paint,Calculator as I have shown above, Run Command Prompt and run scripts etc.

So I hope you will like this sample once you build and run this. Let me know your feedback and I will soon going to post one more P/Invoke sample in coming weeks along with other good and fun stuff on Silverlight 5 RC and then few interesting things on Windows Phone 7 as well.

Vikram.