private void RenderString(WriteableBitmap bitmap, string stringToRender){    TextBlock textBlock = new TextBlock();    textBlock.Text = stringToRender;//设置 font, size,等等    bitmap.Render(textBlock, null);    bitmap.Invalidate();}

WriteableBitmap resizedImage = new WriteableBitmap(imageToResize);//imageToResize is BitmapImageusing (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication())                {using (System.IO.IsolatedStorage.IsolatedStorageFileStream isfs = new IsolatedStorageFileStream(fileName, FileMode.Create, isf))                    {double maxHeight = newWidth;double maxWidth = newHeight;double scaleX = 1;double scaleY = 1;if (pixHt > maxHeight)                            scaleY = maxHeight / pixHt;if (pixWt > maxWidth)                            scaleX = maxWidth / pixWt;

double scale = Math.Min(scaleY, scaleX);int newWidth1 = Convert.ToInt32(pixWt * scale);int newHeight1 = Convert.ToInt32(pixHt * scale);

                    resizedImage.SaveJpeg(isfs, newWidth1, newHeight1, 0, 70);                    isfs.Close();                }            }

WriteableBitmap wb = new WriteableBitmap(UiRoot, null);//将UI页面的根元素传入，可将当面页面的截图保存到WriteableBitmap 

MemoryStream ms = new MemoryStream();

wb.SaveJpeg(ms, myWidth, myHeight, 0, 100);//保存到内存MemoryStream 

BitmapImage bmp = newBitmapImage(); //把截图转化为BitmapImage 

bmp.SetSource(ms);

using (var isoFileStream =newIsolatedStorageFileStream("myPicture.jpg",FileMode.OpenOrCreate,IsolatedStorageFile.GetUserStoreForApplication())) {                         wb.SaveJpeg(isoFileStream, myWidth, myHeight,0,100);  //把截图存储到独立存储                  }

public static byte[] ConvertToBytes(String imageLocation)    {        StreamResourceInfo sri = Application.GetResourceStream(new Uri(imageLocation, UriKind.RelativeOrAbsolute));        BinaryReader binary = new BinaryReader(sri.Stream);

byte[] imgByteArray = binary.ReadBytes((int)(sri.Stream.Length));

        binary.Close();        binary.Dispose();return imgByteArray;    }

public static WriteableBitmap ConvertToImage(Byte[] inputBytes)    {        MemoryStream ms = new MemoryStream(inputBytes);        WriteableBitmap img = new WriteableBitmap(400, 400);

        img.LoadJpeg(ms);

return (img);    }