image1.Source = new BitmapImage(new Uri(@"image file path", Urikind.RelativeOrAbsolute));

System.IO.FileStream fs = new System.IO.FileStream(filepath, System.IO.FileMode.Open, System.IO.FileAccess.Read);

byte[] buffer = new byte[fs.Length]; fs.Read(buffer, 0, buffer.Length);
fs.Close(); fs.Dispose();
System.IO.MemoryStream ms = new System.IO.MemoryStream(buffer);
BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = ms;
bitmapImage.CacheOption = BitmapCacheOption.OnLoad; bitmapImage.EndInit();
ms.Dispose();
image1.Source = bitmapImage;

BitmapImage bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.UriSource = new Uri(szPath);//szPath为图片的全路径
bitmapImage.EndInit();
bitmapImage.Freeze();
image1.Source = bitmapImage;

private BitmapImage BitmapToBitmapImage(System.Drawing.Bitmap bitmap)
{
BitmapImage bitmapImage = new BitmapImage();
using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
{
　　bitmap.Save(ms, bitmap.RawFormat);
　　bitmapImage.BeginInit();
　　bitmapImage.StreamSource = ms;
　　bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
　　bitmapImage.EndInit();
　　bitmapImage.Freeze();
}
　　return bitmapImage;
}

image1.Source = BitmapToBitmapImage(bitmap);

/*-------------------------------------------------------------------------
//Imaging.CreateBitmapSourceFromHBitmap方法，基于所提供的非托管位图和调色板信息的指针，
//返回一个托管的BitmapSource
---------------------------------------------------------------------------*/
Bitmap bitmap = CaptureScreen.GetDesktopImage();
IntPtr ip = bitmap.GetHbitmap();//从GDI+ Bitmap创建GDI位图对象

BitmapSource bitmapSource = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(ip, IntPtr.Zero, Int32Rect.Empty,
System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());

image1.Source = bitmapSource;

BitmapSource m = (BitmapSource)image1.Source;

System.Drawing.Bitmap bmp = new System.Drawing.Bitmap(m.PixelWidth, m.PixelHeight, System.Drawing.Imaging.PixelFormat.Format32bppPArgb); 

System.Drawing.Imaging.BitmapData data = bmp.LockBits(
new System.Drawing.Rectangle(System.Drawing.Point.Empty, bmp.Size), System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppPArgb); 

m.CopyPixels(Int32Rect.Empty, data.Scan0, data.Height * data.Stride, data.Stride); bmp.UnlockBits(data);