Esempio n. 1
0
        /// <summary>
        /// Draw the text supporting clipping according to ClipRegion.
        /// </summary>
        /// <param name="g"></param>
        /// <param name="color"></param>
        /// <param name="rect"></param>
        /// <param name="topOffset"></param>
        /// <param name="orientation"></param>
        /// <param name="fontDescription"></param>
        /// <param name="text"></param>
        /// <param name="contentAlignment"></param>
        /// <param name="flags"></param>
        public static void ClipSupportingDrawText(Graphics g, Color color, Rectangle rect, int topOffset, int orientation, FontDescription fontDescription, String text,
                                                  ContentAlignment contentAlignment, int flags, bool rightToLeft)
        {
            IntPtr region = IntPtr.Zero;
            IntPtr currentclippedRegion = g.Clip.GetHrgn(g);
            bool   IsRegionInfinite     = g.Clip.IsInfinite(g);
            IntPtr hdc = g.GetHdc();

            NativeWindowCommon.SetBkMode(hdc, NativeWindowCommon.TRANSPARENT);
            NativeWindowCommon.SetTextColor(hdc, ColorTranslator.ToWin32(color));

            // Text rectangle as clip Region
            IntPtr clipRegion = NativeWindowCommon.CreateRectRgn(rect.Left, rect.Top, rect.Right, rect.Bottom);

            // If Text starts above control, it needs to clip
            if (topOffset < 0)
            {
                // if current graphics is already clipped, then we need to merge with current text rectangle clip
                if (!IsRegionInfinite)
                {
                    NativeWindowCommon.CombineRgn(currentclippedRegion, currentclippedRegion, clipRegion, NativeWindowCommon.RGN_AND);
                }
            }

            if (IsRegionInfinite)
            {
                // If there is no clip region on graphics, set text rectangle as clip region
                region = clipRegion;
            }
            else if (currentclippedRegion != IntPtr.Zero)
            {
                // use intersected region as clip region
                region = currentclippedRegion;
            }

            // Select resultant clipped region on DC
            if (region != IntPtr.Zero)
            {
                NativeWindowCommon.SelectClipRgn(hdc, region);
            }


            if (clipRegion != IntPtr.Zero)
            {
                NativeWindowCommon.DeleteObject(clipRegion);
            }

            // Draw text
            DrawText(hdc, color, rect, topOffset, orientation, fontDescription, text, contentAlignment, flags, rightToLeft);

            // release objects
            g.ReleaseHdc(hdc);
            if (currentclippedRegion != IntPtr.Zero)
            {
                g.Clip.ReleaseHrgn(currentclippedRegion);
            }
        }
Esempio n. 2
0
        /// <summary>
        /// Paint the border
        /// </summary>
        /// <param name="m"></param>
        private void WMNCPaint(ref Message m)
        {
            IntPtr hDC = NativeWindowCommon.GetWindowDC(m.HWnd);

            if (hDC != IntPtr.Zero)
            {
                IntPtr hrgnWindow = IntPtr.Zero;
                IntPtr hrgnClient = IntPtr.Zero;
                try
                {
                    Rectangle rect = new Rectangle(1, 1, Width - 2, Height - 2);
                    hrgnWindow = NativeWindowCommon.CreateRectRgn(0, 0, Width, Height);
                    hrgnClient = NativeWindowCommon.CreateRectRgn(rect.Left, rect.Top, rect.Right, rect.Bottom);

                    //Creates the union of two combined regions except for any overlapping areas.
                    NativeWindowCommon.CombineRgn(hrgnWindow, hrgnWindow, hrgnClient, NativeWindowCommon.RGN_XOR);
                    NativeWindowCommon.SelectClipRgn(hDC, hrgnWindow);

                    using (Graphics g = Graphics.FromHdc(hDC))
                    {
                        g.Clear(VisualStyleInformation.TextControlBorder);
                    }
                    m.Result = IntPtr.Zero;
                }
                finally
                {
                    NativeWindowCommon.ReleaseDC(m.HWnd, hDC);
                    if (hrgnWindow != IntPtr.Zero)
                    {
                        NativeWindowCommon.DeleteObject(hrgnWindow);
                    }
                    if (hrgnClient != IntPtr.Zero)
                    {
                        NativeWindowCommon.DeleteObject(hrgnClient);
                    }
                }
            }
        }