在wp8中将图像转换为base64

Question

我有一张从我​​的手机图库中拍摄的图片，如下所示：

private void StackPanel_Tap_1(object sender, System.Windows.Input.GestureEventArgs e)
{
    PhotoChooserTask pct = new PhotoChooserTask();
    pct.Show();
    pct.Completed += pct_Completed;
}

void pct_Completed(object sender, PhotoResult e)
{
    BitmapImage img = new BitmapImage();

    if (e.ChosenPhoto != null)
    {
        img.SetSource(e.ChosenPhoto);
        imgphotochoser.Source = img;
    }
}

现在我想通过网络服务将此图像保存在数据库中。所以，我需要将此图像转换为 base64 字符串，但我该怎么做呢？

我试过了，但它抛出了一个异常：

public string imagetobase64(image image,
  system.drawing.imaging.imageformat format)
{
    using (memorystream ms = new memorystream())
    {
        // convert image to byte[]
        image.save(ms, format);
        byte[] imagebytes = ms.toarray();

        // convert byte[] to base64 string
        string base64string = convert.tobase64string(imagebytes);
        return base64string;
    }
}

Answer 1

只需将byte[] 转换为base64 string：

byte[] bytearray = null;

using (MemoryStream ms = new MemoryStream())
{
    if (imgphotochoser.Source != null)
    {
        WriteableBitmap wbitmp = new WriteableBitmap((BitmapImage)imgphotochoser.Source);

        wbitmp.SaveJpeg(ms, 46, 38, 0, 100);
        bytearray = ms.ToArray();
    }
}
string str = Convert.ToBase64String(bytearray);

Base64 转byte[]:

byte[] fileBytes = Convert.FromBase64String(s);

using (MemoryStream ms = new MemoryStream(fileBytes, 0, fileBytes.Length))
{
    ms.Write(fileBytes, 0, fileBytes.Length);
    BitmapImage bitmapImage = new BitmapImage();
    bitmapImage.SetSource(ms);
    return bitmapImage;
}