从颜色创建的图像未添加到视图中？

Question

我尝试从颜色（tutorial）创建一个图像，但它不为我工作：验证码不显示任何图像：

import UIKit 

class ViewController: UIViewController { 

    override func viewDidAppear(animated: Bool) { 
     super.viewDidAppear(animated) 
     let image = ViewController.imageFromColor(UIColor.redColor(), size: CGSizeMake(320,49), radius: 0) 
     println("image \(image.size)") 

     let imageView = UIImageView(image: image) 
     imageView.center = self.view.center 
     self.view.addSubview(imageView) 
    } 

    class func imageFromColor(color:UIColor, size:CGSize, radius:CGFloat)->UIImage 
    { 
     let rect = CGRectMake(0,0, size.width, size.height) 
     UIGraphicsBeginImageContext(rect.size) 
     let context = UIGraphicsGetCurrentContext() 
     CGContextSetFillColorWithColor(context, color.CGColor) 
     var image = UIGraphicsGetImageFromCurrentImageContext() 
     UIGraphicsEndImageContext() 

     UIGraphicsBeginImageContext(size) 
     UIBezierPath(roundedRect: rect, cornerRadius: radius).addClip() 
     image.drawInRect(rect) 
     image = UIGraphicsGetImageFromCurrentImageContext() 
     UIGraphicsEndImageContext() 

     return image 
    } 

} 

日志中的图像大小为320,49，在的viewController在故事板和文件之间连接良好。

感谢

Answer 1

我认为它缺少CGContextFillRect(context, rect);

尝试

let rect = CGRectMake(0, 0, size.width, size.height); 
UIGraphicsBeginImageContext(rect.size); 
let context = UIGraphicsGetCurrentContext(); 

CGContextSetFillColorWithColor(context, color.CGColor); 
CGContextFillRect(context, rect); 

var image = UIGraphicsGetImageFromCurrentImageContext(); 
UIGraphicsEndImageContext(); 

UIGraphicsBeginImageContext(size) 
UIBezierPath(roundedRect: rect, cornerRadius: radius).addClip() 
image.drawInRect(rect) 
image = UIGraphicsGetImageFromCurrentImageContext() 
UIGraphicsEndImageContext() 

return image;