合并 CATextLayer 和 UIImage答案

【问题标题】：Merge CATextLayer and UIImage合并 CATextLayer 和 UIImage
【发布时间】：2015-12-04 22:12:24
【问题描述】：

我想将我的 CATextLayer 与 UIImage 合并为一个 UIImage。我正在使用此代码：

let textViewLayer = CATextLayer()
        textViewLayer.frame = CGRect(origin: CGPoint(x: lockText.imagePositionX, y: lockText.imagePositionY), size: lockImageView.frame.size)
        textViewLayer.string = lockText.textText
        textViewLayer.font = lockText.textFont.fontName
        textViewLayer.fontSize = lockText.textFontSize
        textViewLayer.foregroundColor = lockText.color.CGColor

        let textView = UIView(frame: lockImageView.frame)
        textView.layer.addSublayer(textViewLayer)

        lockImageView.addSubview(textView)

        UIGraphicsBeginImageContext(lockImageView.frame.size)
        textViewLayer.renderInContext(UIGraphicsGetCurrentContext()!)
        image = UIGraphicsGetImageFromCurrentImageContext()


        UIGraphicsEndImageContext();

但是 UIGraphicsGetCurrentContext 是 NIL。谁能告诉我，我做错了什么？

【问题讨论】：

你为什么不改用NString.drawInRect:withAttributes呢？例如，您不需要创建文本层来组合带有文本水印的图像。

标签： ios uiimage calayer uigraphicscontext

【解决方案1】：

我正在使用这段代码来解决我的问题：

UIGraphicsBeginImageContext(image.size);
            image.drawInRect(CGRectMake(0, 0, image.size.width, image.size.height))
            let rect = CGRectMake(lockText.imagePositionX, lockText.imagePositionY, image.size.width, image.size.height);
            lockText.color.set()

            let text = lockText.textText as NSString
            text.drawInRect(rect, withAttributes: [NSFontAttributeName : lockText.textFont, NSForegroundColorAttributeName : lockText.color])
            image = UIGraphicsGetImageFromCurrentImageContext();
            UIGraphicsEndImageContext();

【讨论】：