wpf，vb，位图剪裁的方法

‘ 貌似WPF对GDI+不提供支持，要达到剪裁图像的方法，可以使用image.clip,
’不过clip只是对图片的一个遮挡拦截效果，并不改变本身的图片资源。
‘下面的代码提供了剪裁图片资源的方法。




        Dim path = "C:\Users\Administrator\Desktop\image\image\Images\tori_gaku_02.png"
        Dim bitmap As BitmapSource = New BitmapImage(New Uri(path, UriKind.Absolute))
        ‘获得位图宽度，高度
        Dim width = bitmap.PixelWidth
        Dim height = bitmap.PixelHeight
        Dim bytePerPixel = bitmap.Format.BitsPerPixel / 8
        Dim stride = width * bytePerPixel
        ‘储存位图像素信息
        Dim pixls(stride * height + 1) As Byte
        Dim dpix = bitmap.DpiX
        Dim dpiy = bitmap.DpiY
        Dim format = bitmap.Format ‘PixelFormats.Bgr32 ‘
        Dim palette = bitmap.Palette ‘ Nothing
        ‘设置剪切矩形
        Dim cut As New Int32Rect(0, 0, width * 0.25, height * 0.25)
        Dim cut2 As New Int32Rect(width * 0.25, height * 0.25, width * 0.25, height * 0.25)
        ‘复制指定区域像素信息
        bitmap.CopyPixels(cut2, pixls, stride, 0) ‘用法2：bitmap.CopyPixels(pixls, stride, 0)
        ‘根据复制的像素信息，新建一个位图
        Dim image As BitmapSource = BitmapSource.Create(width * 0.25, height * 0.25, dpix, dpiy, format, palette, pixls, stride)
        ‘新建一个image控件，显示剪裁的位图
        Dim image2 As New Image
        image2.Stretch = Stretch.Fill
        image2.Width = width * 0.25
        image2.Height = height * 0.25
        image2.Source = image
        grid1.Children.Add(image2)