URL(string:) 无法调用非函数类型“字符串"的值 [英] URL(string:) Cannot call value of non-function type 'String'

问题描述

我有以下代码，但出现错误.

I have the follow code but I am getting an error.

if let userImageURL = user.image {
    let url = URL(string: userImageURL)
}

我应该如何创建网址?URL(string:) 应该带一个 String 不是吗?这就是 userImageURL 的含义.

How am I supposed to create url? URL(string:) is supposed to take a String isn't it? And that's what userImageURL is.

这是我试图实现的代码示例.即使在这个例子中，对于 catPictureURL

Here's an example of the code I'm trying to implement. Even in this example, I'm getting the same error for catPictureURL

let catPictureURL = URL(string: "http://i.imgur.com/w5rkSIj.jpg")!

// Creating a session object with the default configuration.
// You can read more about it here https://developer.apple.com/reference/foundation/urlsessionconfiguration
let session = URLSession(configuration: .default)

// Define a download task. The download task will download the contents of the URL as a Data object and then you can do what you wish with that data.
let downloadPicTask = session.dataTask(with: catPictureURL) { (data, response, error) in
    // The download has finished.
    if let e = error {
        print("Error downloading cat picture: \(e)")
    } else {
        // No errors found.
        // It would be weird if we didn't have a response, so check for that too.
        if let res = response as? HTTPURLResponse {
            print("Downloaded cat picture with response code \(res.statusCode)")
            if let imageData = data {
                // Finally convert that Data into an image and do what you wish with it.
                let image = UIImage(data: imageData)
                // Do something with your image.
            } else {
                print("Couldn't get image: Image is nil")
            }
        } else {
            print("Couldn't get response code for some reason")
        }
    }
}

downloadPicTask.resume()

推荐答案

你需要像这样制作URL的对象

You need to make object of URL like this

let url = Foundation.URL(string:"your_url_string")

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