生成缩略图+水印的方法

     //调用示例

     this.MakeSmallImg(f.PostedFile,this.Server.MapPath("1.jpg"),600,500);

     //------------------------------------------------------------

 

     public void MakeSmallImg(System.Web.HttpPostedFile postFile,string saveImg,System.Double Width,System.Double Height)

{

 

     //原始图片名称

     string originalFilename = postFile.FileName;

     //生成的高质量图片名称

     string strGoodFile = saveImg;

 

 

     //从文件取得图片对象

     System.Drawing.Image image = System.Drawing.Image.FromStream(postFile.InputStream,true);

 

     System.Double NewWidth,NewHeight;

     if(image.Width>image.Height)

{

     NewWidth=Width;

     NewHeight=image.Height*(NewWidth/image.Width);

}

     else

{

     NewHeight=Height;

     NewWidth=(NewHeight/image.Height)*image.Width;

}

 

     if (NewWidth>Width)

{

     NewWidth=Width;

}

     if (NewHeight>Height)

{

     NewHeight=Height;

}

 

     //取得图片大小

     System.Drawing.Size size = new Size((int)NewWidth,(int)NewHeight);

     //新建一个bmp图片

     System.Drawing.Image bitmap = new System.Drawing.Bitmap(size.Width,size.Height);

     //新建一个画板

     System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap);

     //设置高质量插值法

     g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High;

     //设置高质量,低速度呈现平滑程度

     g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

     //清空一下画布

     g.Clear(Color.White);

     //在指定位置画图

     g.DrawImage(image, new System.Drawing.Rectangle(0, 0, bitmap.Width, bitmap.Height),

     new System.Drawing.Rectangle(0, 0, image.Width,image.Height),

     System.Drawing.GraphicsUnit.Pixel);

 

 

     ///文字水印

     //System.Drawing.Graphics G=System.Drawing.Graphics.FromImage(bitmap);

     //System.Drawing.Font f=new Font("宋体",10);

     //System.Drawing.Brush b=new SolidBrush(Color.Black);

     //G.DrawString("myohmine",f,b,10,10);

     //G.Dispose();

 

 

 

     ///图片水印

     //System.Drawing.Image copyImage = System.Drawing.Image.FromFile(System.Web.HttpContext.Current.Server.MapPath("pic/1.gif"));

     //Graphics a = Graphics.FromImage(bitmap);

     //a.DrawImage(copyImage, new Rectangle(bitmap.Width-copyImage.Width,bitmap.Height-copyImage.Height,copyImage.Width, copyImage.Height),0,0, copyImage.Width, copyImage.Height, GraphicsUnit.Pixel);

 

     //copyImage.Dispose();

     //a.Dispose();

     //copyImage.Dispose();

 

 

     //保存高清晰度的缩略图

     bitmap.Save(strGoodFile, System.Drawing.Imaging.ImageFormat.Jpeg);

 

     g.Dispose();

     image.Dispose();

     bitmap.Dispose();

}