C # Implementation of the Windows Clipboard Monitor feature example "with demo source download" _c# Tutorial

The example in this article describes the Windows Clipboard Monitor feature implemented by C #. Share to everyone for your reference, specific as follows:

Windows clipboard

The Clipboard (ClipBoard) is an area of memory, a very useful tool built into Windows, with a small clipboard that sets up a color bridge, making it possible to pass and share information between applications. In the ointment, however, the Clipboard retains only one piece of data, and whenever new data is introduced, the old ones are overwritten.

Related Windows APIs

The main thing is setclipboardviewer, which, whenever the contents of the Clipboard changes, adds the window to the chain of windows that are notified by Wm_drawclipboard messages.

Because the handle of the next window in the Clipboard watcher chain has not returned, the application should not pass it in the SetClipboardViewer

The Wm_drawclipboard message received during the call.

If you want to remove the window chain from the Clipboard watcher chain, the application must call the Changeclipboard member function.

#region definitions
//constants for API Calls
... Private Const int wm_drawclipboard = 0x308;
Private Const int wm_changecbchain = 0x30d;
Handle for next Clipboard viewer ...
Private IntPtr Mnextclipboardviewerhwnd;
API declarations
... [DllImport ("user32.dll", CharSet = CharSet.Auto)]
static public extern IntPtr SetClipboardViewer (IntPtr hwndnewviewer);
[DllImport ("user32.dll", CharSet = CharSet.Auto)]
static public extern bool Changeclipboardchain (IntPtr HWnd, IntPtr hwndnext);
[DllImport ("user32.dll", CharSet = CharSet.Auto)]
public static extern int SendMessage (IntPtr hWnd, int msg, int wParam, int lParam);
#endregion

WndProc function

The operating system sends a series of messages to the application, such as a left-click and A-button lift, and the application will eventually submit the message to the window procedure (wndproc[English full name Windows process]) to a pointer to an application-defined window procedure via GetMessage.

We need to rewrite this function to handle the Clipboard content Change event:

#region message Process//override WndProc to get messages ... protected Override void WndProc (ref message m) {switch ( m.msg) {case Wm_drawclipboard: {//the clipboard has changed ...//########################### ###############################################//Process Clipboard here:) ...//###. .......... ..... ####################################################################### SendMessage (MNextClipBoardViewerHWnd, M.
        MSG, M.wparam.toint32 (), M.lparam.toint32 ()); Displays the text information in the Clipboard if (Clipboard.containstext ()) {Label1.
        Text = Clipboard.gettext (); //Show picture information in Clipboard if (Clipboard.containsimage ()) {pictureBox1.Image = Clipboard.getimage (
          );
        Picturebox1.update ();
      } break; Case Wm_changecbchain: {//another Clipboard viewer has removed itself ... if (M.wparam = = (Int
     PTR) Mnextclipboardviewerhwnd)   {Mnextclipboardviewerhwnd = m.LParam;
        else {SendMessage (Mnextclipboardviewerhwnd, M.msg, M.wparam.toint32 (), M.lparam.toint32 ());
      } break; } base.
WndProc (ref m);

 } #endregion

Effect Chart:

Full instance code click here to download the site.

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