在Swift

Question

我想在Swift中从多个UIBezierPaths的数组创建一个UIImage。

我尝试了以下代码：

func convertPathsToImage(paths: [UIBezierPath]) -> UIImage{

    let imageWidth: CGFloat = 200
    let imageHeight: CGFloat  = 200

    let colorSpace:CGColorSpace = CGColorSpaceCreateDeviceRGB()!
    let bitmapInfo = CGBitmapInfo(rawValue: CGImageAlphaInfo.PremultipliedLast.rawValue)
    let context = CGBitmapContextCreate(nil, Int(imageWidth), Int(imageHeight), 8, 0, colorSpace, bitmapInfo.rawValue)

    CGContextBeginPath(context);

    UIColor.blackColor().set()

    for path in paths{
        path.stroke()
    }

    let newImageRef = CGBitmapContextCreateImage(context);
    let newImage = UIImage(CGImage: newImageRef!)

    return newImage
}

结果是空图像。

有人可以解释一下我做错了什么吗？非常感谢你！

Answer 1

我不能告诉你你做错了什么，但我遇到了类似的问题，这段代码对我有用。

func convertPathsToImage(paths: [UIBezierPath]) -> UIImage
{
    let imageWidth: CGFloat = 200
    let imageHeight: CGFloat  = 200
    let strokeColor:UIColor = UIColor.blackColor()

    // Make a graphics context
    UIGraphicsBeginImageContextWithOptions(CGSize(width: imageWidth, height: imageHeight), false, 0.0)
    let context = UIGraphicsGetCurrentContext()

    CGContextSetStrokeColorWithColor(context, strokeColor.CGColor)

    for path in paths {
        path.stroke()
    }
    let image = UIGraphicsGetImageFromCurrentImageContext()

    UIGraphicsEndImageContext()

    return image
}