System.NotSupportedException HResult = 0x80131515消息=找不到适合完成此操作的映像组件

Question

1. 我正在保存图像并从sql server 2017中检索图像，当我正在检索异常显示时

2. 错误“ System.NotSupportedException HResult = 0x80131515 Message =未找到适合完成此操作的成像组件”

3. Microsoft SQL Server Studio 2017

4. 以下是用于从sql server 2017检索图像的代码块

   SqlConnection con;
   String sqlstr = "select photo from img Where itmNO='" + txt1.Text +  "'";
   string conString = ConfigurationManager.ConnectionStrings["connectionString"].ConnectionString;
   con = new SqlConnection(conString);
   con.Open();
   SqlCommand cmd1 = new SqlCommand(sqlstr, con);
   object value = cmd1.ExecuteScalar();
   byte[] imageData = (byte[])value;
   if (imageData != null && imageData.Length > 0)
   {
   var imag = new BitmapImage();
   using (var mem = new MemoryStream(imageData))
   {
           mem.Position = 0;
           mem.Write(imageData, 0, imageData.Length - 0);
           imag.BeginInit();
           imag.CreateOptions = BitmapCreateOptions.PreservePixelFormat;
           imag.CacheOption = BitmapCacheOption.OnLoad;
           imag.UriSource = null;
           imag.StreamSource = mem;
           imag.EndInit();
    }
    imag.Freeze();
    img2.Source = imag;
    }
   

5。提前谢谢 当我保存字节数组时，字节长度显示为84254，但是在检索时，它的长度仅显示13，但是我无法理解为什么会发生