如何处理NSData并返回UIImage(Swift) [英] How to handle NSData and return UIImage (Swift)

问题描述

我正在尝试从无后端数据库&的URL中检索图像.将其转换为图像，然后使用UIImageView返回该函数.如何在此代码中处理NSError并仍然返回UIImageView?

I am trying to retrieve an image from a URL from a backendless database & convert this into an image, and return the function with a UIImageView. How do I handle a NSError in this code, and still return the UIImageView?

func getImage() -> UIView {

    let imageLink = backendless.userService.currentUser.getProperty("Avatar")

    let URL = NSURL(string: imageLink as! String)

    let data = NSData(contentsOfURL: URL!)

    let image: UIImage!

    image = UIImage(data: data!)

    return UIImageView(image: image!)
}

推荐答案

根据评论更新了我的答案.

Updated my answer based on the comments.

如果您要查找的占位符图像不可用，您可以返回一个占位符图像:

You can return a placeholder image if the one you are looking for is not available:

所以您的方法将如下所示:

So your method will look like the following:

func getImage() -> UIImage {

    var imageLink = backendless.userService.currentUser.getProperty("Avatar")

    guard let imageUrl = imageLink as? String,
        let URL = NSURL(string: imageUrl),
        let data = NSData(contentsOfURL: URL)
         else {
            return UIImage(named: "placeholder")
    }

    return UIImage(data: data)
}

这是您的使用方式:

func koloda(koloda: KolodaView, viewForCardAtIndex index: UInt) -> UIView {
    return UIImageView(image: getImage())
}

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