如何检查图像行为

Question

这是我的图像宽度和大小代码，这是完美的工作，但问题是当我传递null fileupload它给我错误'参数无效'但我想传递null值也将如何做

HttpPostedFile fil = this.FileUp.PostedFile;
                 System.Drawing.Image uploadimage = System.Drawing.Image.FromStream(fil.InputStream);
                 if (uploadimage.Height > 155 || uploadimage.Width > 124)
                 {
                     lblErrorMsg.Visible = true;
                     lblErrorMsg.Text = "<font class='orange'>Height and width not accpetable</font>";
                     return;

                 }

Answer 1

然后在继续...

之前检查FileUpload控件的HasFile属性

if (this.FileUp.PostedFile.HasFile)
{
  // continue...
}

点击此处：FileUpload.HasFile Property