UIImage PNG着色

Question

我想在用户单击它时着色PNG。

我在Xcode here中找到了一个例子，但是当我在C＃中尝试时，我无法检索图像。

这里是我写的代码：

public UIImage DrawSelectedBorder(UIImage image) 
{ 
    UIGraphics.BeginImageContextWithOptions(image.Size, false, image.CurrentScale); // for correct resolution on retina, thanks @MobileVet 
    CGContext context = UIGraphics.GetCurrentContext(); 

    context.TranslateCTM(0, image.Size.Height); 
    context.ScaleCTM((System.nfloat)1.0, (System.nfloat)(-1.0)); 

    CGRect rect = new CGRect(0, 0, image.Size.Width, image.Size.Height); 

    context.SetBlendMode(CGBlendMode.Normal); 
    context.SetFillColor(UIColor.Black.CGColor); 
    context.FillRect(rect); 


    // draw original image 
    context.SetBlendMode(CGBlendMode.Normal); 
    context.DrawImage(rect,image.CGImage); 

    // tint image (losing alpha) - the luminosity of the original image is preserved 
    context.SetBlendMode(CGBlendMode.Color); 
    context.FillRect(rect); 

    // mask by alpha values of original image 
    context.SetBlendMode(CGBlendMode.DestinationIn); 
    context.DrawImage(rect, image.CGImage); 

    UIImage coloredImage = UIGraphics.GetImageFromCurrentImageContext(); 
    UIGraphics.EndImageContext(); 

    return coloredImage; 
} 

Answer 1

只是想你的代码。一切都是正确的，但是你并没有选择你想要填入PNG的颜色。

变化：

// tint image (losing alpha) - the luminosity of the original image is preserved 
context.SetBlendMode(CGBlendMode.Color); 
context.FillRect(rect); 

到：

// tint image (losing alpha) - the luminosity of the original image is preserved 
context.SetBlendMode(CGBlendMode.Color); 
context.SetFillColor(UIColor.Red.CGColor); 
context.FillRect(rect);