当使用谷歌方向Api和请求数据json得到nil数据

Question

我是swift编程和ios开发的新手。我正在尝试绘制两个地点之间的路线，遇到了这个问题。

func getDirections(origin: String!, destination: String!, waypoints: Array<String>!, travelMode: AnyObject!, completionHandler: ((status: String, success: Bool) -> Void)) {
    if let originLocation = origin {
        if let destinationLocation = destination {
            var directionsURLString = baseURLDirections + "origin=" + originLocation + "&destination=" + destinationLocation
            directionsURLString = directionsURLString.stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!
            let directionsURL = NSURL(string: directionsURLString)
            dispatch_async(dispatch_get_main_queue(), { () -> Void in
                let directionsData = NSData(contentsOfURL: directionsURL!)
                println(directionsData)
                var error: NSError?
                let dictionary: Dictionary<NSObject, AnyObject> = NSJSONSerialization.JSONObjectWithData(directionsData!, options: NSJSONReadingOptions.MutableContainers, error: &error) as! Dictionary<NSObject, AnyObject>

我得到错误:

致命错误:在展开可选值

时意外发现nil

我试着打印我收到的数据，结果是nil

let baseURLDirections = "https://maps.googleapis.com/maps/api/directios/json?"

Answer 1

您的请求URL中没有包含API key。

您可以使用NSURLSession来执行指示API请求。当你从API响应中得到数据时，你可以使用NSJSONSerialization.JSONObjectWithData()来解析JSON日期。

 func directionAPITest() {
        let directionURL = "https://maps.googleapis.com/maps/api/directions/json?origin=Toronto&destination=Montreal&key=YOUR_API_KEY"
        let request = NSURLRequest(URL: NSURL(string:directionURL)!)
        let session = NSURLSession.sharedSession()
        session.dataTaskWithRequest(request,
            completionHandler: {(data: NSData!, response: NSURLResponse!, error: NSError!) in
                if error == nil {
                    let object = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: nil) as! NSDictionary
                    println(object)
                    let routes = object["routes"] as! [NSDictionary]
                    for route in routes {
                        println(route["summary"])
                    }
                    dispatch_async(dispatch_get_main_queue()) {
                      //update your UI here 
                    }
                }
                else {
                    println("Direction API error")
                }
        }).resume()
    }

如果你需要更新你的mapView或UITableView，你可以在dispatch_async(dispatch_get_main_queue())闭包内完成。

Answer 2

您没有在您请求的URL Not API key中包含Serverkey…创建一个服务器密钥并等待大约10分钟来激活。