如何在WPF中裁剪图像并保存到ImageSource？ [英] How to crop image and save into ImageSource in WPF?

问题描述

我是WPF的新学员。我有一个问题。
我有一张图片，宽度：360，高度：360。在这里，我想裁剪如下图像：

（0,0）到（120,120）保存到第一个ImageSource对象，

（120,0）到（240,120）保存到第二个ImageSource对象，

（240,0）到（360,120）保存到第三个ImageSource对象;，

......

请参阅下图中的更多详情：

我的代码示例如下：

  private void CutImage（string img）
 {
 int iLeft = 0; 
 int iTop = 0; 
 int count = 0; 
 
 Image thisImg = new Image（）; 
 BitmapImage src = new BitmapImage（）; 
 src.BeginInit（）; 
 src.UriSource = new Uri（img，UriKind.Relative）; 
 src.CacheOption = BitmapCacheOption.OnLoad; 
 src.EndInit（）; 
 thisImg.Source = src; 
 
 for（int i = 0; i< 3; i ++）
 {
 iTop = i * 120; 
 for（int j = 0; j< 3; j ++）
 {
 iLeft = j * 120; 
 
 Canvas canvas = new Canvas（）; 
 
 Rectangle destRect = new Rectangle（）; 
 destRect.SetValue（Canvas.LeftProperty，（double）0）; 
 destRect.SetValue（Canvas.TopProperty，（double）0）; 
 destRect.Width = destRect.Height = 120; 
 
 Rect srcRect = new Rect（）; 
 srcRect.X = iLeft; 
 srcRect.Y = iTop; 
 srcRect.Width = srcRect.Height = 120; 
 
 
 thisImg.Clip = new RectangleGeometry（srcRect）; 
 
 thisImg.Clip.SetValue（Canvas.TopProperty，（double）iTop）; 
 thisImg.Clip.SetValue（Canvas.LeftProperty，（double）iLeft）; 
 thisImg.Clip.SetValue（Canvas.WidthProperty，（double）120）; 
 thisImg.Clip.SetValue（Canvas.HeightProperty，（double）120）; 
 
 objImg [count ++] =（ImageSource）thisImg.GetValue（Image.SourceProperty）; 
} 
} 
} 
  

但它不起作用正如我所料，似乎所有的ImageSource对象都存储相同的图像，而不是corping部分。任何人都可以帮助我吗？使用 CroppedBitmap 执行此操作：

  private void CutImage（string img）
 {
 int count = 0; 
 
 BitmapImage src = new BitmapImage（）; 
 src.BeginInit（）; 
 src.UriSource = new Uri（img，UriKind.Relative）; 
 src.CacheOption = BitmapCacheOption.OnLoad; 
 src.EndInit（）; 
 
 for（int i = 0; i< 3; i ++）
 for（int j = 0; j< 3; j ++）
 objImg [count ++] = new CroppedBitmap（src，new Int32Rect（j * 120，i * 120,120,120））; 
} 
  

I am new learner to WPF. here I got a question. I have a image, width:360, height:360. Here I want to crop this image like below:

( 0,0 ) to (120,120) save to the first ImageSource object,

(120,0 ) to (240,120) save to the second ImageSource object,

(240,0 ) to (360,120) save to the third ImageSource object;,

……

pls see more details in below picture:

My code sample below:

    private void CutImage(string img)
    {
        int iLeft = 0;
        int iTop = 0;
        int count = 0;

        Image thisImg = new Image();
        BitmapImage src = new BitmapImage();
        src.BeginInit();
        src.UriSource = new Uri(img, UriKind.Relative);
        src.CacheOption = BitmapCacheOption.OnLoad;
        src.EndInit();
        thisImg.Source = src;

        for (int i = 0; i < 3; i++)
        {
            iTop = i * 120;
            for (int j = 0; j < 3; j++)
            {
                iLeft = j * 120;

                Canvas canvas = new Canvas();

                Rectangle destRect = new Rectangle();
                destRect.SetValue(Canvas.LeftProperty, (double)0);
                destRect.SetValue(Canvas.TopProperty,(double)0);
                destRect.Width = destRect.Height = 120;

                Rect srcRect = new Rect();
                srcRect.X = iLeft;
                srcRect.Y = iTop;
                srcRect.Width = srcRect.Height = 120;


                thisImg.Clip = new RectangleGeometry(srcRect);

                thisImg.Clip.SetValue(Canvas.TopProperty, (double)iTop);
                thisImg.Clip.SetValue(Canvas.LeftProperty, (double)iLeft);
                thisImg.Clip.SetValue(Canvas.WidthProperty, (double)120);
                thisImg.Clip.SetValue(Canvas.HeightProperty,(double)120);

                objImg[count++] = (ImageSource)thisImg.GetValue(Image.SourceProperty);
            }
        }
      }

but it doesn't work as I expected, seems that all the ImageSource objects store the same image, not the corping part. Any one can help me ? thx.

解决方案

Use CroppedBitmap to do this:

private void CutImage(string img)
{
    int count = 0;

    BitmapImage src = new BitmapImage();
    src.BeginInit();
    src.UriSource = new Uri(img, UriKind.Relative);
    src.CacheOption = BitmapCacheOption.OnLoad;
    src.EndInit();

    for (int i = 0; i < 3; i++)
        for (int j = 0; j < 3; j++)
            objImg[count++] = new CroppedBitmap(src, new Int32Rect(j * 120, i * 120, 120, 120));
}

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