Windows Phone 8.1的自定义Xaml裁剪控件

Question

I am writing a Windows Phone 8.1 app that requires me to crop an image to produce another square image (250 by 250) . I need xaml and code behind sample code that I can be use to do the cropping. The examples found online are for the old WP8 and they are not very helpful.Any assistance will be appreciated.

Answer 1

I did find a solution, there is this article I came across and it has two parts. Part 1 and Part 2 proved helpful in finding a solution with minimal modifications such as using WriteableBitmapEx methods for cropping instead. I hope this will help someone in future and save them the pain I went through.

Here is also some code I used to center crop my image

 public static WriteableBitmap centerCropImage(WriteableBitmap image)
    {


        int originalWidth = image.PixelWidth;
        int originalHeight = image.PixelHeight;

        //Getting the new width
        int newWidth = originalWidth > originalHeight? originalHeight : originalWidth;

        //Calculating the cropping points
        int cropStartX, cropStartY;
        if(originalWidth > originalHeight){
            cropStartX = (originalWidth - newWidth)/2;
            cropStartY = 0; 
        }
        else{
            cropStartY = (originalHeight - newWidth)/2;
            cropStartX = 0; 
        }

        //Then use the following values to get the cropped image

        var cropped = image.Crop(new Rect(cropStartX, cropStartY, newWidth, newWidth));

        //Then resize the new square image to 250 by 250 px
        var resized = WriteableBitmapExtensions.Resize(cropped, 250, 250, WriteableBitmapExtensions.Interpolation.NearestNeighbor);

        return resized;
    }