Graphics.FromHwnd Method

You should always call the Dispose method to release the Graphics and related resources created by the FromHwnd method.

The following code example is designed for use with Windows Forms, and it requires PaintEventArgs e, which is a parameter of the Paint event handler, as well as thisForm, the Form for the example. The code performs the following actions:

• Creates a new internal pointer variable hwnd and sets it to the handle of the example's form.

• Creates a new Graphics from the handle.

• Draws a rectangle to the new Graphics using a red pen.

• Disposes the new Graphics.

private void FromHwndHwnd(PaintEventArgs e)
{

    // Get handle to form.
    IntPtr hwnd = this.Handle;

    // Create new graphics object using handle to window.
    Graphics newGraphics = Graphics.FromHwnd(hwnd);

    // Draw rectangle to screen.
    newGraphics.DrawRectangle(new Pen(Color.Red, 3), 0, 0, 200, 100);

    // Dispose of new graphics.
    newGraphics.Dispose();
}

.NET Framework

.NET Framework Client Profile

• SecurityPermission 

  for access to unmanaged code. Related enumeration: UnmanagedCode.

Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference