Image.GetThumbnailImageAbort

Question

我对委托不是很清楚，System.Drawing.Image.GetThumbnailImageAbort mycall = new System.Drawing.Image.GetThumbnailImageAbort(bool1);
是怎么用的？能举个简单的例子吗？
protected void Page_Load(object sender, EventArgs e)
    {
        System.Drawing.Image.GetThumbnailImageAbort mycall = new System.Drawing.Image.GetThumbnailImageAbort(bool1);
        Bitmap image = new Bitmap(Session["filename"].ToString());
        System.Drawing.Image image1 = image.GetThumbnailImage(80, 80, mycall, IntPtr.Zero);
        image1.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
    }
    public bool bool1()
    {
        return false;
    }

Answer 1

GetThumbnailImageAbort提供一个回调方法，用于确定 GetThumbnailImage 方法应在何时提前取消执行。如果此方法确定 GetThumbnailImage 方法应提前停止执行，则它返回 true；否则返回 false。 private void GenThumbnailImage()
{
     System.Drawing.Image image = System.Drawing.Image.FromFile(Server.MapPath("test.jpg"));
     System.Drawing.Image.GetThumbnailImageAbort callBack = new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallBack);
     System.Drawing.Image thumbImage = image.GetThumbnailImage(image.Width/10, image.Height/10, callBack, new System.IntPtr());
     thumbImage.Save(Server.MapPath("Sample.jpg"));
     image.Dispose();
     thumbImage.Dispose();
}private bool ThumbnailCallBack()
{
     return true;
}对c#委托的解释：http://blog.myspace.cn/e/401642074.htm