Ios 将字符串强制转换为NSURL将返回nil

我正在尝试从url获取图像，如下所示：

var string = "https://maps.googleapis.com/maps/api/staticmap?key=AIzaSyAJeHxZaZuNsYimNCJ4r0yuO-OYM8cINOI&center=6.241381,-75.595083&zoom=13&size=600x300&path=color:0x0000ff|weight:5|6.241381,-75.595083&signature=u7sM3m2h-qFSJoARR7cqD0CSBvU="

let url = NSURL(string: string.stringByRemovingPercentEncoding!)

if let data = NSData(contentsOfURL: url){
      let image = UIImage(data: data)
}

https://maps.googleapis.com/maps/api/staticmap?key=AI...OI&center=6.241381%2B-75.595083&zoom=13&size=600x300&path=color%3A0x0000ff%7Cweight%3A5%7C6.241381%2B-75.595083&&signature=u7...=

但是它在

url

中返回nil。似乎url不存在，但确实存在，如果您转到url，您将看到一个图像

---

那么演员阵容有什么问题？或者我怎样才能得到这个图像

这就是我如何使用

编辑 您的url包含对url无效的|，因此您可以使用百分比编码

这里有一个例子

let strurl = "https://maps.googleapis.com/maps/api/staticmap?key=AIzaSyAJeHxZaZuNsYimNCJ4r0yuO-OYM8cINOI&center=6.241381,-75.595083&zoom=13&size=600x300&path=color:0x0000ff|weight:5|6.241381,-75.595083&signature=u7sM3m2h-qFSJoARR7cqD0CSBvU="
let myURL = NSURL(string: strurl.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet())!)
self.imgView.af_setImageWithURL(myURL!, placeholderImage: nil, filter: nil,  imageTransition: .CrossDissolve(0.5), runImageTransitionIfCached: false, completion:  { (error) in
            // do Something when asynchronous image loading is completed
        })

---

问题在于URL查询部分的垂直条（

|

）。应将其转义为

%7C

下面是我将如何构造自动转义查询部分的URL：

var components = NSURLComponents(string: "https://maps.googleapis.com/maps/api/staticmap")!
components.query = "key=AIzaSyAJeHxZaZuNsYimNCJ4r0yuO-OYM8cINOI&center=6.241381,-75.595083&zoom=13&size=600x300&path=color:0x0000ff|weight:5|6.241381,-75.595083&signature=u7sM3m2h-qFSJoARR7cqD0CSBvU="

if let url = components.url {
    // ...
}

---

如果您使用的是Swift 3，

NSURLComponents

将重命名为

URLComponents

，您必须按如下方式向查询中添加百分比编码：

Swift 2.3

let domainAPI = "https://maps.googleapis.com/maps/api/staticmap?"
let query = "key=AIzaSyAJeHxZaZuNsYimNCJ4r0yuO-OYM8cINOI&center=6.241381,-75.595083&zoom=13&size=600x300&path=color:0x0000ff|weight:5|6.241381,-75.595083&signature=u7sM3m2h-qFSJoARR7cqD0CSBvU="
if let queryPercentEncoded = query.stringByAddingPercentEncodingWithAllowedCharacters(.URLQueryAllowedCharacterSet()),
    let url = NSURL(string: domainAPI + queryPercentEncoded) {
    print(url)
}

if let queryPercentEncoded = query.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed),
    let url = URL(string: domainAPI + queryPercentEncoded) {
    print(url)
}

Swift 3

let domainAPI = "https://maps.googleapis.com/maps/api/staticmap?"
let query = "key=AIzaSyAJeHxZaZuNsYimNCJ4r0yuO-OYM8cINOI&center=6.241381,-75.595083&zoom=13&size=600x300&path=color:0x0000ff|weight:5|6.241381,-75.595083&signature=u7sM3m2h-qFSJoARR7cqD0CSBvU="
if let queryPercentEncoded = query.stringByAddingPercentEncodingWithAllowedCharacters(.URLQueryAllowedCharacterSet()),
    let url = NSURL(string: domainAPI + queryPercentEncoded) {
    print(url)
}

if let queryPercentEncoded = query.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed),
    let url = URL(string: domainAPI + queryPercentEncoded) {
    print(url)
}

（我没有使用基于密钥的身份验证，因此某些部分可能需要修改。）

首先，您需要一个不带签名的正确转义URL字符串：

let key = "AI...OI" // better hide your actual key in a public space...
let rawURLString = "https://maps.googleapis.com/maps/api/staticmap?key=\(key)&center=6.241381%2B-75.595083&zoom=13&size=600x300&path=color%3A0x0000ff%7Cweight%3A5%7C6.241381%2B-75.595083"
//`rawURLString` needs to be a valid string representation of URL.
assert(NSURL(string: rawURLString) != nil)

然后，为URL字符串生成base64编码的签名：

let encodedSignature: String = generateEncodedSignature(rawURLString, secret: yourSecretKey)

let signedURLString = "\(rawURLString)&signature=\(encodedSignature)"

之后，您可以创建一个签名URL字符串：

let encodedSignature: String = generateEncodedSignature(rawURLString, secret: yourSecretKey)

let signedURLString = "\(rawURLString)&signature=\(encodedSignature)"

（我相信你有一些功能可以在你的应用程序中生成签名或签名url，请根据它修改上述代码。）

signedURLString

的内容应如下所示：

var string = "https://maps.googleapis.com/maps/api/staticmap?key=AIzaSyAJeHxZaZuNsYimNCJ4r0yuO-OYM8cINOI&center=6.241381,-75.595083&zoom=13&size=600x300&path=color:0x0000ff|weight:5|6.241381,-75.595083&signature=u7sM3m2h-qFSJoARR7cqD0CSBvU="

let url = NSURL(string: string.stringByRemovingPercentEncoding!)

if let data = NSData(contentsOfURL: url){
      let image = UIImage(data: data)
}

https://maps.googleapis.com/maps/api/staticmap?key=AI...OI&center=6.241381%2B-75.595083&zoom=13&size=600x300&path=color%3A0x0000ff%7Cweight%3A5%7C6.241381%2B-75.595083&&signature=u7...=

（

签名

不能以“u7”开头。）

并使用

signedURLString

创建

NSURL

。不要删除百分比编码

let url = NSURL(string: signedURLString)

---

您是在真正的iOS设备浏览器上输入该URL，还是使用计算机的浏览器？@LeoDabus我尝试了，但没有删除百分比和相同的内容。@rmaddy我正在使用计算机的浏览器。您必须使用从实际的iOS设备工作的URL。使用Mobile Safari测试URL并查看您得到了什么。它在iOS设备@rmaddyTry上使用给定的URL工作。问题是我的NSURL返回零，因此您无法下载图像。我使用新的

NSURL

收到此消息：您得到此消息是因为管道“|”已转换为“%7C”.@Mr.UB那么我能做些什么来查看图像呢？有一种方法可以使不同的url成为通用的，看看url是从谷歌地图给出的一些坐标来的，那么如果url带有其他参数呢。。。

组件。查询

也可以吗？