Xamarin Mac - 调整图像大小

Question

我正尝试像以前在 iOS-应用程序中那样调整我的 Mac-应用程序中的图像大小。问题是 NSImage 不包含 UIImage 的所有方法。这是我用于 iOS

的代码

public static UIImage MaxResizeImage(this UIImage sourceImage, float maxWidth, float maxHeight)
    {
        var sourceSize = sourceImage.Size;
        var maxResizeFactor = Math.Max(maxWidth / sourceSize.Width, maxHeight / sourceSize.Height);
        if (maxResizeFactor > 1) return sourceImage;
        float width = (float)(maxResizeFactor * sourceSize.Width);
        float height = (float)(maxResizeFactor * sourceSize.Height);
        UIGraphics.BeginImageContext(new SizeF(width, height));
        sourceImage.Draw(new RectangleF(0, 0, width, height));
        var resultImage = UIGraphics.GetImageFromCurrentImageContext();
        UIGraphics.EndImageContext();
        return resultImage;
    }

如何为 Mac-App 重写它？感谢您的帮助

Answer 1

我的 Mac 应用程序有一个可用功能，重写它以适合您的功能。尚未测试此版本，但它应该可以工作。

public static NSImage MaxResizeImage(this NSImage sourceImage, float maxWidth, float maxHeight)
{
    var sourceSize = sourceImage.Size;
    var maxResizeFactor = Math.Max(maxWidth / sourceSize.Width, maxHeight / sourceSize.Height);
    if (maxResizeFactor > 1) return sourceImage;
    float width = (float)(maxResizeFactor * sourceSize.Width);
    float height = (float)(maxResizeFactor * sourceSize.Height);
    var targetRect = new CoreGraphics.CGRect(0,0,width, height);
    var newImage = new NSImage (new CoreGraphics.CGSize (width, height));
    newImage.LockFocus ();
    sourceImage.DrawInRect(targetRect, CoreGraphics.CGRect.Empty, NSCompositingOperation.SourceOver, 1.0f);
    newImage.UnlockFocus ();

    return newImage;
}

Xamarin Mac - 调整图像大小

Xamarin Mac - Resize Image

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