c# - 如何在Monotouch Xamarin中裁剪图像

我在UIImageview中显示图像，我想裁剪图像，这是我的要求。

选择裁剪图标应显示一个固定大小（600X600）的正方形，该正方形固定在图像上并带有网格线，以帮助拉直图像。将有一个控件，允许在网格下旋转图像。

最佳答案

这就是我最终用来对图像进行中心裁剪的内容。

//Crops an image to even width and height
public UIImage CenterCrop(UIImage originalImage)
{
    // Use smallest side length as crop square length
    double squareLength = Math.Min(originalImage.Size.Width, originalImage.Size.Height);

    nfloat x, y;
    x = (nfloat)((originalImage.Size.Width - squareLength) / 2.0);
    y = (nfloat)((originalImage.Size.Height - squareLength) / 2.0);

    //This Rect defines the coordinates to be used for the crop
    CGRect croppedRect = CGRect.FromLTRB(x, y, x + (nfloat)squareLength, y + (nfloat)squareLength);

    // Center-Crop the image
    UIGraphics.BeginImageContextWithOptions(croppedRect.Size, false, originalImage.CurrentScale);
    originalImage.Draw(new CGPoint(-croppedRect.X, -croppedRect.Y));
    UIImage croppedImage = UIGraphics.GetImageFromCurrentImageContext();
    UIGraphics.EndImageContext();

    return croppedImage;
}