//添加图片水印
protected void WaterMarkByImg()
{
//实例化组件
ASPJPEGLib.IASPJpeg objJpeg = new ASPJPEGLib.ASPJpeg();
//打开图片文件
objJpeg.Open(Server.MapPath("images/tu.JPG"));
//实例化logo组件
ASPJPEGLib.ASPJpeg Logo = new ASPJPEGLib.ASPJpeg();
//打开logo图片文件
Logo.Open(Server.MapPath("images/01.jpg"));
Logo.Width = 10;
Logo.Height = Logo.Width * Logo.OriginalHeight / Logo.OriginalWidth;//重新定义大小
//将logo合并到图片中去
objJpeg.DrawImage(objJpeg.OriginalWidth-Logo.OriginalWidth, objJpeg.OriginalHeight-Logo.OriginalHeight, Logo, 0, "#000000", 0);
objJpeg.Save(Server.MapPath("images/tu.JPG"));
objJpeg = null;//注销组件，释放资源
}

你没贴出具体错误啊

Invalid 5th argument, must be a long integer.
说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.IndexOutOfRangeException: Invalid 5th argument, must be a long integer.

源错误:


行 50: Logo.Height = Logo.Width * Logo.OriginalHeight / Logo.OriginalWidth;//重新定义大小
行 51: //将logo合并到图片中去
行 52: objJpeg.DrawImage(objJpeg.OriginalWidth - Logo.OriginalWidth, objJpeg.OriginalHeight - Logo.OriginalHeight, Logo, 0, "#000000", 0);
行 53: objJpeg.Save(Server.MapPath("images/tu1.JPG"));
行 54: objJpeg = null;//注销组件，释放资源


源文件: e:\zds\Demo\watermark\web\Default.aspx.cs 行: 52

行 52: objJpeg.DrawImage(objJpeg.OriginalWidth - Logo.OriginalWidth, objJpeg.OriginalHeight - Logo.OriginalHeight, Logo, 0, "#000000", 0);
Invalid 5th argument, must be a long integer.
第5个参数错误，必须你长整型

必须为长整型

我改成00000了 没报错了 可是水印没添加上去啊

水印位置没调整好吧