/// <summary>
/// Draws composited text onto the glass area of a form.
/// </summary>
/// <param name="dc">The <see cref="IDeviceContext"/> onto which the composited text should be drawn.</param>
/// <param name="text">The text to draw.</param>
/// <param name="font">The <see cref="Font"/> to apply to the drawn text.</param>
/// <param name="bounds">The <see cref="Rectangle" /> that represents the bounds of the text.</param>
/// <param name="padding">The <see cref="Padding"/> around the text; necessary to allow space for the glow effect.</param>
/// <param name="foreColor">The <see cref="Color" /> to apply to the drawn text.</param>
/// <param name="textFormat">A bitwise combination of the <see cref="TextFormatFlags" /> values.</param>
/// <param name="glowSize">Specifies the size of a glow that will be drawn on the background prior to any text being drawn.</param>
/// <remarks>
/// <para>
/// Do not use this method to draw text on non-glass areas of a form.
/// </para>
/// </remarks>
/// <exception cref="NotSupportedException">The current operating system does not support glass, or the Desktop Window Manager is not enabled.</exception>
/// <exception cref="ArgumentNullException"><paramref name="dc"/>, <paramref name="text"/> or <paramref name="font"/> is <see langword="null"/>.</exception>
public static void DrawCompositedText(IDeviceContext dc, string text, Font font, Rectangle bounds, Padding padding, Color foreColor, int glowSize, TextFormatFlags textFormat)
{
if (!IsDwmCompositionEnabled)
{
throw new NotSupportedException(Properties.Resources.GlassNotSupportedError);
}
if (dc == null)
{
throw new ArgumentNullException("dc");
}
if (text == null)
{
throw new ArgumentNullException("text");
}
if (font == null)
{
throw new ArgumentNullException("font");
}
IntPtr primaryHdc = dc.GetHdc();
try
{
using (SafeDeviceHandle memoryHdc = NativeMethods.CreateCompatibleDC(primaryHdc))
using (SafeGDIHandle fontHandle = new SafeGDIHandle(font.ToHfont(), true))
using (SafeGDIHandle dib = NativeMethods.CreateDib(bounds, primaryHdc, memoryHdc))
{
NativeMethods.SelectObject(memoryHdc, fontHandle);
// Draw glowing text
System.Windows.Forms.VisualStyles.VisualStyleRenderer renderer = new System.Windows.Forms.VisualStyles.VisualStyleRenderer(System.Windows.Forms.VisualStyles.VisualStyleElement.Window.Caption.Active);
NativeMethods.DTTOPTS dttOpts = new NativeMethods.DTTOPTS();
dttOpts.dwSize = Marshal.SizeOf(typeof(NativeMethods.DTTOPTS));
dttOpts.dwFlags = NativeMethods.DrawThemeTextFlags.Composited | NativeMethods.DrawThemeTextFlags.GlowSize | NativeMethods.DrawThemeTextFlags.TextColor;
dttOpts.crText = ColorTranslator.ToWin32(foreColor);
dttOpts.iGlowSize = glowSize;
NativeMethods.RECT textBounds = new NativeMethods.RECT(padding.Left, padding.Top, bounds.Width - padding.Right, bounds.Height - padding.Bottom);
NativeMethods.DrawThemeTextEx(renderer.Handle, memoryHdc, 0, 0, text, text.Length, (int)textFormat, ref textBounds, ref dttOpts);
// Copy to foreground
const int SRCCOPY = 0x00CC0020;
NativeMethods.BitBlt(primaryHdc, bounds.Left, bounds.Top, bounds.Width, bounds.Height, memoryHdc, 0, 0, SRCCOPY);
}
}
finally
{
dc.ReleaseHdc();
}
}
public static SafeGDIHandle CreateDib(Rectangle bounds, IntPtr primaryHdc, SafeDeviceHandle memoryHdc)
{
BITMAPINFO info = new BITMAPINFO();
info.biSize = Marshal.SizeOf(info);
info.biWidth = bounds.Width;
info.biHeight = -bounds.Height;
info.biPlanes = 1;
info.biBitCount = 32;
info.biCompression = 0; // BI_RGB
SafeGDIHandle dib = CreateDIBSection(primaryHdc, info, 0, IntPtr.Zero, IntPtr.Zero, 0);
SelectObject(memoryHdc, dib);
return(dib);
}
/// <summary>
/// Provides the size, in pixels, of the specified text.
/// </summary>
/// <param name="dc">The device context in which to measure the text.</param>
/// <param name="text">The text to measure.</param>
/// <param name="font">The <see cref="Font"/> to apply to the measured text.</param>
/// <param name="textFormat">A bitwise combination of the <see cref="TextFormatFlags" /> values.</param>
/// <returns>The <see cref="Size"/>, in pixels, of <paramref name="text"/> drawn with the specified <paramref name="font"/> and format.</returns>
/// <exception cref="NotSupportedException">The current operating system does not support glass, or the Desktop Window Manager is not enabled.</exception>
/// <exception cref="ArgumentNullException"><paramref name="dc"/>, <paramref name="text"/> or <paramref name="font"/> is <see langword="null"/>.</exception>
public static Size MeasureCompositedText(IDeviceContext dc, string text, Font font, TextFormatFlags textFormat)
{
if (!IsDwmCompositionEnabled)
{
throw new NotSupportedException(Properties.Resources.GlassNotSupportedError);
}
if (dc == null)
{
throw new ArgumentNullException("dc");
}
if (text == null)
{
throw new ArgumentNullException("text");
}
if (font == null)
{
throw new ArgumentNullException("font");
}
IntPtr primaryHdc = dc.GetHdc();
try
{
Rectangle bounds = new Rectangle(0, 0, int.MaxValue, int.MaxValue);
using (SafeDeviceHandle memoryHdc = NativeMethods.CreateCompatibleDC(primaryHdc))
using (SafeGDIHandle fontHandle = new SafeGDIHandle(font.ToHfont(), true))
using (SafeGDIHandle dib = NativeMethods.CreateDib(bounds, primaryHdc, memoryHdc))
{
NativeMethods.SelectObject(memoryHdc, fontHandle);
System.Windows.Forms.VisualStyles.VisualStyleRenderer renderer = new System.Windows.Forms.VisualStyles.VisualStyleRenderer(System.Windows.Forms.VisualStyles.VisualStyleElement.Window.Caption.Active);
NativeMethods.RECT bounds2 = new NativeMethods.RECT(bounds);
NativeMethods.RECT rect;
NativeMethods.GetThemeTextExtent(renderer.Handle, memoryHdc, 0, 0, text, text.Length, (int)textFormat, ref bounds2, out rect);
return(new Size(rect.Right - rect.Left, rect.Bottom - rect.Top));
}
}
finally
{
dc.ReleaseHdc();
}
}
public static extern void GetThemeTextExtent(IntPtr hTheme, SafeDeviceHandle hdc, int iPartId, int iStateId, string text, int iCharCount, int dwTextFlags, [In] ref RECT bounds, out RECT rect);
public static extern void DrawThemeTextEx(IntPtr hTheme, SafeDeviceHandle hdc, int iPartId, int iStateId, string text, int iCharCount, int dwFlags, ref RECT pRect, ref DTTOPTS pOptions);
public static extern bool BitBlt(IntPtr hdc, int nXDest, int nYDest, int nWidth, int nHeight, SafeDeviceHandle hdcSrc, int nXSrc, int nYSrc, uint dwRop);
public static extern IntPtr SelectObject(SafeDeviceHandle hDC, SafeGDIHandle hObject);