Rants, rambles, news and notes from another geek

Getting the Desktop Window From .NET

I don’t organize my Windows desktop like most people. I like to have my icons in rows not columns. So I get very annoyed anytime something on the system causes a desktop refresh. Suddenly all of my icons are back where Microsoft decided they should be instead of where I decided they should be.

I’ve been thinking about writing an app to do this for a few years, but I never got around to starting one until today.

I decided to create a solution spike to learn a few things that I didn’t know already. First problem? How do I talk to the desktop window from .NET.

As far as I can tell you can’t do it using Windows Forms… you have to use P/Invoke. So I created a quick little WinForms app to test it out.

I created a Form and added a button to it. Then I added the following event handler.

[DllImport("user32.dll", EntryPoint="SendMessage")] 
public static extern int SendMessage(IntPtr hWnd,
                                      int Msg,
                                      int wParam,
                                      int lParam); 

private static extern int FindWindow(string _ClassName,
                                      string _WindowName);

[DllImport ("user32.dll")]
public static extern IntPtr GetWindow( IntPtr handle, int cmd );

private void button1_Click(object sender, System.EventArgs e)
  const int LVA_DEFAULT = 0x0000;
  const int LVM_FIRST = 0x1000; // ListView messages
  const int LVM_ARRANGE = (LVM_FIRST + 22);
  const int GW_CHILD = 5;

  int tmp = FindWindow( "ProgMan", null );
  IntPtr handle = new IntPtr(tmp);
  handle = GetWindow( handle, GW_CHILD );
  handle = GetWindow( handle, GW_CHILD );

  SendMessage( handle, LVM_ARRANGE, LVA_DEFAULT, 0 );

Success! The desktop arranged itself.

Next task… figuring out how to actually arrange icons in a list view.