C# 如何在xamarin Android中裁剪旋转图像？

我的要求是在旋转后裁剪图像

样本：

我的真实形象：

轮换后：

在这里，我将图像旋转了45度。现在我只想裁剪高亮显示的（红色矩形）矩形区域。

代码：

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请告诉我如何在旋转后找到图像坐标点。

您可以裁剪屏幕视图并自定义屏幕框架

例如，

CustomShot

方法如下：

public Bitmap CustomShot(Activity activity, int x, int y, int w, int h)
{
    // get the top view of windows
    View view = activity.Window.DecorView;
    view.BuildDrawingCache();

    // get the height of status bar
    Rect rect = new Rect();
    view.GetWindowVisibleDisplayFrame(rect);
    int statusBarHeights = rect.Top;
    Display display = activity.WindowManager.DefaultDisplay;

    // get the width and height of screen
    if (w == 0)
    {
        w = display.Width;
    }
       
    int heights = display.Height;

    // allow cache
    view.DrawingCacheEnabled = true;

    // custom the crop frame
    Bitmap bmp = Bitmap.CreateBitmap(view.GetDrawingCache(true), x,
            y, w, h);

    // clear cache
    view.DestroyDrawingCache();

    return bmp;
}

private void Cropbutton_Click(object sender, System.EventArgs e)
{
    if(imageBitmap == null){
        imageBitmap = ViewToBitmap();
        this.imageView.SetImageBitmap(GetCroppedBitmap(imageBitmap, points));
    }else{
        this.imageView.SetImageBitmap(CustomShot( this, 0, 300, 0, 500));
        this.imageView.SetScaleType(ImageView.ScaleType.FitCenter);
        this.imageView.Rotation = 0;
    }
}

然后在

Cropbutton\u单击
方法中使用，如下所示：

public Bitmap CustomShot(Activity activity, int x, int y, int w, int h)
{
    // get the top view of windows
    View view = activity.Window.DecorView;
    view.BuildDrawingCache();

    // get the height of status bar
    Rect rect = new Rect();
    view.GetWindowVisibleDisplayFrame(rect);
    int statusBarHeights = rect.Top;
    Display display = activity.WindowManager.DefaultDisplay;

    // get the width and height of screen
    if (w == 0)
    {
        w = display.Width;
    }
       
    int heights = display.Height;

    // allow cache
    view.DrawingCacheEnabled = true;

    // custom the crop frame
    Bitmap bmp = Bitmap.CreateBitmap(view.GetDrawingCache(true), x,
            y, w, h);

    // clear cache
    view.DestroyDrawingCache();

    return bmp;
}

private void Cropbutton_Click(object sender, System.EventArgs e)
{
    if(imageBitmap == null){
        imageBitmap = ViewToBitmap();
        this.imageView.SetImageBitmap(GetCroppedBitmap(imageBitmap, points));
    }else{
        this.imageView.SetImageBitmap(CustomShot( this, 0, 300, 0, 500));
        this.imageView.SetScaleType(ImageView.ScaleType.FitCenter);
        this.imageView.Rotation = 0;
    }
}

其效果是：