保存圖像

Question

我想保存圖像中充滿紅色的長方形，但我得到了一個文件，該文件不是一個圖像，這是我的代碼：

protected void btnDrowRect_Click(object sender, EventArgs e) 
    { 

    string fn1 = Session["WorkingImage"].ToString(); 

    string imagePath = Server.MapPath("~/Images/rec" + fn1); 
    string savetoo = Server.MapPath("~/Images/rect/rec" + DateTime.Now.ToString("hhmmss")); 
    string imageNewPath = savetoo; ; 

    Image image = Image.FromFile(imagePath); 

    int a = Int32.Parse(imgw.Value)/2 - img3.Width/2; 
    int b = Int32.Parse(imgh.Value)/2 - img3.Height/2; 

    Rectangle srcRect = new Rectangle(-a, -b, Int32.Parse(imgw.Value),Int32.Parse(imgh.Value)); 
    Bitmap bmp = new Bitmap(Int32.Parse(imgw.Value), Int32.Parse(imgh.Value)); 
    using (Graphics g = Graphics.FromImage(bmp)) 
    { 
     // Create image. 
     Image newImage = Image.FromFile(imagePath); 

     // Create rectangle for displaying image. 
     Rectangle destRect = new Rectangle(0, 0, Int32.Parse(imgw.Value), Int32.Parse(imgh.Value)); 

     // Create rectangle for source image. 

     GraphicsUnit units = GraphicsUnit.Pixel; 

     Color customColor = Color.FromArgb(100, Color.Red); 
     SolidBrush shadowBrush = new SolidBrush(customColor); 
     g.FillRectangles(shadowBrush, new RectangleF[] { destRect }); 

     // Draw image to screen. 
     g.DrawImage(newImage, destRect, srcRect, units); 
     // g.Save(); 

    } 

    bmp.Save(imageNewPath); 

} 

點擊此處查看所保存的文件：

http://i.stack.imgur.com/Nso3c.png

但我想保存這樣的：

http://i.stack.imgur.com/B7CUl.png

Answer 1

你可以嘗試

string savetoo = Server.MapPath("~/Images/rect/rec" + DateTime.Now.ToString("hhmmss") + ".jpg"); 

和

bmp.Save(imageNewPath, ImageFormat.Jpeg); 

，這將是工作