c# - 如何清除WritableBitmap的内存

Question

我正在使用从图库中挑选图像PhotoChooserTask，这是我的设置

private void ApplicationBarIconButton_Click(object sender, EventArgs e)
{
    PhotoChooserTask photo = new PhotoChooserTask();
    photo.Completed += photo_Completed;
    photo.Show();
}

void photo_Completed(object sender, PhotoResult e)
{
    if (e.ChosenPhoto != null)
    {
        WriteableBitmap wbmp1 = PictureDecoder.DecodeJpeg(e.ChoosenPhoto, (int)scrnWidth, (int)scrnHeight);
        ImageBrush iBru = new ImageBrush();
        iBru.ImageSource = wbmp1;
        iBru.Stretch = Stretch.Fill;
        ContentPanel.Background = iBru;
    }
}

问题：这种方式只适用于.JPEG图像

为了使它与 other 一起工作image formats，我尝试了这个：

void photo_Completed(object sender, PhotoResult e)
{
    if (e.ChosenPhoto != null)
    {
        WriteableBitmap wBmp = new WriteableBitmap(0, 0);//6930432
        wBmp.SetSource(e.ChosenPhoto);//23105536
        MemoryStream tmpStream = new MemoryStream();//23105536
        wBmp.SaveJpeg(tmpStream, (int)scrnWidth, (int)scrnHeight, 0, 100);//22831104
        tmpStream.Seek(0, SeekOrigin.Begin);//22831104

        WriteableBitmap wbmp1 = PictureDecoder.DecodeJpeg(tmpStream, (int)scrnWidth, (int)scrnHeight);//24449024
        ImageBrush iBru = new ImageBrush();//24449024
        iBru.ImageSource = wbmp1;//24449024
        iBru.Stretch = Stretch.Fill;
        ContentPanel.Background = iBru;
    }
}

这种方式适用于不同的图像格式，但内存效率不高。

bytes为了更好地理解，我在每行之后提到了使用的数量。

问题：在后面的代码片段中，我不再需要 wbmp，如何清除 wbmp 对象使用的内存？

Answer 1

正如@Soonts 建议我使用的那样BitmapImage，它解决了我的目的，

BitmapImage bmp = new BitmapImage();
bmp.DecodePixelWidth = (int)scrnWidth;
bmp.DecodePixelHeight = (int)scrnHeight;
bmp.SetSource(e.ChosenPhoto);

它消耗更少memory，我们可以scale下来image

Answer 2

摆脱 WriteableBitmap，改为执行以下操作：

var bmp = new System.Windows.Media.Imaging.BitmapImage();
bmp.SetSource( e.ChosenPhoto );
var ib = new ImageBrush() { ImageSource = bmp, Stretch = Stretch.Fill };
ContentPanel.Background = ib;