Question

您好我正在尝试创建转换器以在数据库中转换我的图像，数据类型为“Varbinary（Max）” 在WPF中填充我的DataGrid，但我有2个错误，我向你展示转换器：

public class BinaryToImageConverter : IValueConverter
 {

public object Convert(object value, System.Type targetType, object parameter, 

System.Globalization.CultureInfo culture)
    {

   Binary binaryData =  value;// here there is the first error .How convert BinaryData to Object??
        if (binaryData == null) {
            return null;
         }

        byte[] buffer = binaryData.ToArray();
        if (buffer.Length == 0) {
              return null;
         }

          BitmapImage res = new BitmapImage();
         res.BeginInit();
         res.StreamSource = new System.IO.MemoryStream(buffer);
           res.EndInit();
         return res;
      }

     public object ConvertBack(object value, System.Type targetType, object parameter, System.Globalization.CultureInfo culture)
      {
         BitmapImage source = value;//How convert Bitmap to Object?
          if (source == null) {
              return null;
          }
          if ((source.StreamSource != null) && source.StreamSource.Length > 0) {
             return GetBytesFromStream(source.StreamSource);
         }

         return null;
      }

     private Binary GetBytesFromStream(System.IO.Stream stream)
     {
           stream.Position = 0;
         byte[] res = new byte[stream.Length + 1];
        using (System.IO.BinaryReader reader = new System.IO.BinaryReader(stream)) {
              reader.Read(res, 0, (int)stream.Length);
         }
          return new Binary(res);
     }

 }

出租车你建议我，如果它是正确的或有更好的方法来做到这一点？谢谢你的帮助。祝你有个美好的一天

Answer 1

如果value参数确实包含BinaryData类型的对象，那么你可以对其进行类型转换：

Binary binaryData =  (Binary)value;

或

Binary binaryData =  value as Binary;

最好在转换之前对value参数执行is-null检查，而不是像现在一样在转换之后执行它。

转换器二进制到图像WPF;

1 个答案: