雀悅 - 恢復自由了

若要示範，先將兩種透明度技巧標記為註解再執行應用程式，以查看影像沒有設定透明度時出現的樣子。然後針對其中一種技巧，取消註解程式碼。

// The .NET Compact Framework supports transparency,

// but with only one transparency color. 

// The SetColorKey method must have the same color  

// specified for the low color and high color range. 

 // Note that you must uncomment lines of code 

// as indicated for the desired transparency effect.  

protected override void OnPaint(PaintEventArgs e) {     

// Create a red and black bitmap to demonstrate transparency.     

Bitmap bmp = new Bitmap(75,75);     

Graphics g = Graphics.FromImage(bmp);      

g.FillEllipse(new SolidBrush(Color.Red), 0, 0, bmp.Width, bmp.Width);     

g.DrawLine(new Pen(Color.Black), 0, 0, bmp.Width, bmp.Width);     

g.DrawLine(new Pen(Color.Black), bmp.Width, 0, 0, bmp.Width);     

g.Dispose();      ImageAttributes attr = new ImageAttributes();      

// Set the transparency color key based on the upper-left pixel      

// of the image.     

// Uncomment the following line to make all black pixels transparent:     

// attr.SetColorKey(bmp.GetPixel(0, 0), bmp.GetPixel(0, 0));     

 // Set the transparency color key based on a specified value.     

// Uncomment the following line to make all red pixels transparent:     

// attr.SetColorKey(Color.Red, Color.Red);      

// Draw the image using the image attributes.     

Rectangle dstRect = new Rectangle(0, 0, bmp.Width, bmp.Height);     

e.Graphics.DrawImage(bmp, dstRect, 0, 0, bmp.Width, bmp.Height,GraphicsUnit.Pixel, attr); 

}