picturebox1为相机采集的视频窗口,当点击button1时,弹出透明异形窗体AlphaForm并显示红方框,现在的问题是,当鼠标点击Form1标题栏移动时,AlphaForm是固定的,如何让AlphaForm跟随移动,还有红框相对于 picturebox1 坐标如何计算,窗体代码如下:
请教详细思路与代码实现,本人菜鸟,基础薄弱
namespace WindowsFormsApplication4
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
pictureBox1.Load(@"c:\u.png");
}
private void button1_Click(object sender, EventArgs e)
{
Bitmap bmp = new Bitmap(200, 200);
Graphics g = Graphics.FromImage(bmp);
Pen p = new Pen(Color.Red, 2);
g.DrawRectangle(p, 0, 0, 50, 50);
AlphaForm putForm = new AlphaForm(); //alpha通道的显示图像窗体
putForm.Location = new Point(200, 200);
putForm.SetBitmap(bmp, 255); //设置图像
putForm.Show(); //显示窗体
}
}
}
namespace WindowsFormsApplication4
{
public partial class AlphaForm : Form
{
class Alpha_Win32
{
public enum Bool
{
False = 0,
True
};
[StructLayout(LayoutKind.Sequential)]
public struct Point
{
public Int32 x;
public Int32 y;
public Point(Int32 x, Int32 y) { this.x = x; this.y = y; }
}
[StructLayout(LayoutKind.Sequential)]
public struct Size
{
public Int32 cx;
public Int32 cy;
public Size(Int32 cx, Int32 cy) { this.cx = cx; this.cy = cy; }
}
[StructLayout(LayoutKind.Sequential, Pack = 1)]
struct ARGB
{
public byte Blue;
public byte Green;
public byte Red;
public byte Alpha;
}
[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct BLENDFUNCTION
{
public byte BlendOp;
public byte BlendFlags;
public byte SourceConstantAlpha;
public byte AlphaFormat;
}
public const Int32 ULW_COLORKEY = 0x00000001;
public const Int32 ULW_ALPHA = 0x00000002;
public const Int32 ULW_OPAQUE = 0x00000004;
public const byte AC_SRC_OVER = 0x00;
public const byte AC_SRC_ALPHA = 0x01;
[DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
public static extern Bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref Point pptDst, ref Size psize, IntPtr hdcSrc, ref Point pprSrc, Int32 crKey, ref BLENDFUNCTION pblend, Int32 dwFlags);
[DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
public static extern IntPtr GetDC(IntPtr hWnd);
[DllImport("user32.dll", ExactSpelling = true)]
public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);
[DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
public static extern IntPtr CreateCompatibleDC(IntPtr hDC);
[DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
public static extern Bool DeleteDC(IntPtr hdc);
[DllImport("gdi32.dll", ExactSpelling = true)]
public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
[DllImport("gdi32.dll", ExactSpelling = true, SetLastError = true)]
public static extern Bool DeleteObject(IntPtr hObject);
}
public AlphaForm()
{
FormBorderStyle = FormBorderStyle.None;
DoubleBuffered = true;
TopMost = true;
}
public void SetBitmap(Bitmap bitmap)
{
SetBitmap(bitmap, 255);
}
public void SetBitmap(Bitmap bitmap, byte opacity)
{
/*
if (bitmap.PixelFormat != PixelFormat.Format32bppArgb)
throw new ApplicationException("The bitmap must be 32ppp with alpha-channel."+ bitmap.PixelFormat);
*/
IntPtr screenDc = Alpha_Win32.GetDC(IntPtr.Zero);
IntPtr memDc = Alpha_Win32.CreateCompatibleDC(screenDc);
IntPtr hBitmap = IntPtr.Zero;
IntPtr oldBitmap = IntPtr.Zero;
try
{
hBitmap = bitmap.GetHbitmap(Color.FromArgb(0));
oldBitmap = Alpha_Win32.SelectObject(memDc, hBitmap);
Alpha_Win32.Size size = new Alpha_Win32.Size(bitmap.Width, bitmap.Height);
Alpha_Win32.Point pointSource = new Alpha_Win32.Point(0, 0);
Alpha_Win32.Point topPos = new Alpha_Win32.Point(Left, Top);
Alpha_Win32.BLENDFUNCTION blend = new Alpha_Win32.BLENDFUNCTION();
blend.BlendOp = Alpha_Win32.AC_SRC_OVER;
blend.BlendFlags = 0;
blend.SourceConstantAlpha = opacity;
blend.AlphaFormat = Alpha_Win32.AC_SRC_ALPHA;
Alpha_Win32.UpdateLayeredWindow(Handle, screenDc, ref topPos, ref size, memDc, ref pointSource, 0, ref blend, Alpha_Win32.ULW_ALPHA);
GC.Collect();
}
finally
{
Alpha_Win32.ReleaseDC(IntPtr.Zero, screenDc);
if (hBitmap != IntPtr.Zero)
{
Alpha_Win32.SelectObject(memDc, oldBitmap);
Alpha_Win32.DeleteObject(hBitmap);
}
Alpha_Win32.DeleteDC(memDc);
}
}
protected override CreateParams CreateParams
{
get
{
CreateParams cp = base.CreateParams;
cp.ExStyle |= 0x00080000;
return cp;
}
}
我最终想要这种效果
这种效果代码如何实现