Exemple #1
0
 public static extern bool EndPaint(IntPtr hWnd, ref PAINTSTRUCT ps);
		protected override void WndProc(ref Message m)
		{
			switch(m.Msg)
			{
				//Do all painting in WM_PAINT to reduce flicker.
				case (int)Win32.Msgs.WM_ERASEBKGND:
					return;

				case (int)Win32.Msgs.WM_PAINT:

					// This code is influenced by Steve McMahon's article:
					// "Painting in the MDI Client Area".
					// http://vbaccelerator.com/article.asp?id=4306

					// Use Win32 to get a Graphics object.
					Win32.PAINTSTRUCT paintStruct = new Win32.PAINTSTRUCT();
					IntPtr screenHdc = User32.BeginPaint(m.HWnd, ref paintStruct);

					using(Graphics screenGraphics = Graphics.FromHdc(screenHdc)) 
					{
						// Get the area to be updated.
						Rectangle clipRect = paintStruct.rcPaint;

						// Double-buffer by painting everything to an image and
						// then drawing the image.
						int width = (MdiClient.ClientRectangle.Width > 0 ? MdiClient.ClientRectangle.Width : 0);
						int height = (MdiClient.ClientRectangle.Height > 0 ? MdiClient.ClientRectangle.Height : 0);
						if (width > 0 && height > 0)
						{
							using(Image i = new Bitmap(width, height))
							{
								using(Graphics g = Graphics.FromImage(i))
								{
									// This code comes from J Young's article:
									// "Generating missing Paint event for TreeView and ListView".
									// http://www.codeproject.com/cs/miscctrl/genmissingpaintevent.asp

									// Draw base graphics and raise the base Paint event.
									IntPtr hdc = g.GetHdc();
									Message printClientMessage = Message.Create(m.HWnd, (int)Win32.Msgs.WM_PRINTCLIENT, hdc, IntPtr.Zero);  
									DefWndProc(ref printClientMessage);
									g.ReleaseHdc(hdc);

									// Draw the image here.
									if(Image != null)
										DrawImage(g, clipRect);

									// Call our OnPaint here to draw graphics over the
									// original and raise our Paint event.
									OnPaint(new PaintEventArgs(g, clipRect));
								}

								// Now draw all the graphics at once.
								screenGraphics.DrawImage(i, MdiClient.ClientRectangle);
							}
						}
					}

					User32.EndPaint(m.HWnd, ref paintStruct);
					return;
	
				case (int)Win32.Msgs.WM_SIZE:
					// Repaint on every resize.
					MdiClient.Invalidate();
					break;
					

				case (int)Win32.Msgs.WM_NCCALCSIZE:
					// If AutoScroll is set to false, hide the scrollbars when the control
					// calculates its non-client area.
					if(!AutoScroll)
						User32.ShowScrollBar(m.HWnd, (int)Win32.ScrollBars.SB_BOTH, 0 /*false*/);
					break;
			}
		
			base.WndProc(ref m);
		}
Exemple #3
0
 public static extern IntPtr BeginPaint(IntPtr hWnd, ref PAINTSTRUCT ps);
Exemple #4
0
        protected override void WndProc(ref Message m)
        {
            switch (m.Msg)
            {
            //Do all painting in WM_PAINT to reduce flicker.
            case (int)Win32.Msgs.WM_ERASEBKGND:
                return;

            case (int)Win32.Msgs.WM_PAINT:

                // This code is influenced by Steve McMahon's article:
                // "Painting in the MDI Client Area".
                // http://vbaccelerator.com/article.asp?id=4306

                // Use Win32 to get a Graphics object.
                Win32.PAINTSTRUCT paintStruct = new Win32.PAINTSTRUCT();
                IntPtr            screenHdc   = User32.BeginPaint(m.HWnd, ref paintStruct);

                using (Graphics screenGraphics = Graphics.FromHdc(screenHdc))
                {
                    // Get the area to be updated.
                    Rectangle clipRect = paintStruct.rcPaint;

                    // Double-buffer by painting everything to an image and
                    // then drawing the image.
                    int width  = (MdiClient.ClientRectangle.Width > 0 ? MdiClient.ClientRectangle.Width : 0);
                    int height = (MdiClient.ClientRectangle.Height > 0 ? MdiClient.ClientRectangle.Height : 0);
                    if (width > 0 && height > 0)
                    {
                        using (Image i = new Bitmap(width, height))
                        {
                            using (Graphics g = Graphics.FromImage(i))
                            {
                                // This code comes from J Young's article:
                                // "Generating missing Paint event for TreeView and ListView".
                                // http://www.codeproject.com/cs/miscctrl/genmissingpaintevent.asp

                                // Draw base graphics and raise the base Paint event.
                                IntPtr  hdc = g.GetHdc();
                                Message printClientMessage = Message.Create(m.HWnd, (int)Win32.Msgs.WM_PRINTCLIENT, hdc, IntPtr.Zero);
                                DefWndProc(ref printClientMessage);
                                g.ReleaseHdc(hdc);

                                // Draw the image here.
                                if (Image != null)
                                {
                                    DrawImage(g, clipRect);
                                }

                                // Call our OnPaint here to draw graphics over the
                                // original and raise our Paint event.
                                OnPaint(new PaintEventArgs(g, clipRect));
                            }

                            // Now draw all the graphics at once.
                            screenGraphics.DrawImage(i, MdiClient.ClientRectangle);
                        }
                    }
                }

                User32.EndPaint(m.HWnd, ref paintStruct);
                return;

            case (int)Win32.Msgs.WM_SIZE:
                // Repaint on every resize.
                MdiClient.Invalidate();
                break;


            case (int)Win32.Msgs.WM_NCCALCSIZE:
                // If AutoScroll is set to false, hide the scrollbars when the control
                // calculates its non-client area.
                if (!AutoScroll)
                {
                    User32.ShowScrollBar(m.HWnd, (int)Win32.ScrollBars.SB_BOTH, 0 /*false*/);
                }
                break;
            }

            base.WndProc(ref m);
        }