iOS中来自CALayer的UIImage [英] UIImage from CALayer in iOS

问题描述

在我的应用程序中，我创建了一个CALayer(具有几个子层-CALayer由添加为子层的形状组成).

In my application, I have created a CALayer (with a few sublayers - the CALayer is composed of shapes added as sublayers).

我正在尝试创建一个UIImage，我可以将其上传到服务器(我有相应的代码). 但是，我不知道如何将CALayer添加到UIImage.

I am trying to create a UIImage that I will be able to upload to a server (I have the code for this). However, I can't figure out how to add the CALayer to a UIImage.

这可能吗?

推荐答案

听起来像您想将图层渲染到UIImage中.在这种情况下，下面的方法应该可以解决问题.只需将其添加到您的视图或控制器类中，或在CALayer上创建一个类别.

Sounds like you want to render your layer into a UIImage. In that case, the method below should do the trick. Just add this to your view or controller class, or create a category on CALayer.

Obj-C

- (UIImage *)imageFromLayer:(CALayer *)layer
{
  UIGraphicsBeginImageContextWithOptions(layer.frame.size, NO, 0);

  [layer renderInContext:UIGraphicsGetCurrentContext()];
  UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();

  UIGraphicsEndImageContext();

  return outputImage;
}

快速

func imageFromLayer(layer:CALayer) -> UIImage {
    UIGraphicsBeginImageContextWithOptions(layer.frame.size, layer.isOpaque, 0)
    layer.render(in: UIGraphicsGetCurrentContext()!)
    let outputImage = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return outputImage!
}

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