public GlowEdgeDrawingContext(/*int width, int height*/)
{
_screenDC = ApiUser32.GetDC(IntPtr.Zero);
if (ScreenDC == IntPtr.Zero)
{
throw new Exception(nameof(ScreenDC));
}
_windowDC = ApiGdi32.CreateCompatibleDC(ScreenDC);
if (WindowDC == IntPtr.Zero)
{
throw new Exception(nameof(WindowDC));
}
_backgroundDC = ApiGdi32.CreateCompatibleDC(ScreenDC);
if (BackgroundDC == IntPtr.Zero)
{
throw new Exception(nameof(BackgroundDC));
}
_blend.BlendOp = (byte)AlphaBlendControl.AC_SRC_OVER; // 唯一值
_blend.BlendFlags = 0; // 必须 0
_blend.SourceConstantAlpha = 0xFF; // 不增加额外的 Alpha 值，一切以源为主
_blend.AlphaFormat = (byte)AlphaBlendControl.AC_SRC_ALPHA; // 使用源的 Alpha 通道
//_windowBitmap = new GlowWindowBitmap(ScreenDC, width, height);
//ApiGdi32.SelectObject(_windowDC, _windowBitmap.Handle);
}
public void Resize(int width, int height)
{
if (_windowBitmap != null)
{
_windowBitmap.Dispose();
}
_windowBitmap = new GlowWindowBitmap(ScreenDC, width, height);
ApiGdi32.SelectObject(_windowDC, _windowBitmap.Handle);
}
protected override void DisposeNativeResources()
{
if (BackgroundDC != IntPtr.Zero)
{
ApiGdi32.DeleteDC(BackgroundDC);
}
if (WindowDC != IntPtr.Zero)
{
ApiGdi32.DeleteDC(WindowDC);
}
if (ScreenDC != IntPtr.Zero)
{
ApiUser32.ReleaseDC(IntPtr.Zero, ScreenDC);
}
}
private readonly IntPtr _pbits; // 边框位图数据
#endregion
private GlowEdgeBitmap(IntPtr screenDC, int width, int height)
{
_bitmapInfo.bmiHeader.biSize = Marshal.SizeOf(typeof(BITMAPINFOHEADER));
_bitmapInfo.bmiHeader.biWidth = width;
_bitmapInfo.bmiHeader.biHeight = -height;
_bitmapInfo.bmiHeader.biPlanes = 1; // 必须是1
_bitmapInfo.bmiHeader.biBitCount = 32;
_bitmapInfo.bmiHeader.biCompression = BIC.BI_RGB;
_bitmapInfo.bmiHeader.biSizeImage = 0; // 未压缩的 RGB
_bitmapInfo.bmiHeader.biXPelsPerMeter = 0;
_bitmapInfo.bmiHeader.biYPelsPerMeter = 0;
_bitmapInfo.bmiHeader.biClrUsed = 0; /// <see cref="BITMAPINFO.bmiColors"/> 大小为0
_bitmapInfo.bmiHeader.biClrImportant = 0;
Handle = ApiGdi32.CreateDIBSection(
screenDC,
ref _bitmapInfo,
0,
out _pbits,
IntPtr.Zero,
0
);
}
/// <summary>
/// 释放 HBITMAP。CreateXXX 创建的内容要是用 DeleteXXX 进行释放。
/// </summary>
protected override void DisposeNativeResources()
{
ApiGdi32.DeleteObject(Handle);
}
