UIImage PNG 着色 [英] UIImage PNG coloration
本文介绍了UIImage PNG 着色的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想在用户点击时为 PNG 着色.
I would like to color a PNG when user clicks on it.
我在 Xcode 中找到了一个例子 在这里但是当我在 C# 中尝试时,我无法检索图像.
I found an example in Xcode here but when I try it in C# I can't Retrieve the image.
这是我写的代码:
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;
}
推荐答案
刚刚尝试了您的代码.一切正常,但您没有选择要在 PNG 中填充的颜色.
Just tried your code. Everything is right but you didn't choose the color you want to fill in your PNG.
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);
这篇关于UIImage PNG 着色的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
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