Question

我想在 swift 为google places api执行请求，之后我会得到结果我想将它们存储在tableview中。我想我以非正统的方式解决了这个问题。我使用dispatch_time 6秒（这是请求获取所有数据的时间）但是在我将它们放入表视图后，表视图有滞后并且移动缓慢。我想以正确的方式做到这一点。有谁知道怎么做？

这是我试过的：

self.fetchPlacesNearCoordinate（self.locValue1，radius：1000，name：＆＃34; food＆＃34;）

      showActivityIndicator()
        let delay = 6 * Double(NSEC_PER_SEC)
        let time = dispatch_time(DISPATCH_TIME_NOW, Int64(delay))
        dispatch_after(time, dispatch_get_main_queue()) {
           self.activities()
            self.hideActivityIndicator()

        }

其中fetchPlacesNearCoordinate（）是我的函数，它使得google的请求放置api

编辑1

这就是fetchPlacesNearCoordinate（）函数的实现方式：

func fetchPlacesNearCoordinate（坐标：CLLocationCoordinate2D，radius：Double，name：String）{ var urlString =＆＃34; https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=(locValue1.latitude),(locValue1.longitude)&rankby=distance&types=food＆＃34; urlString + =＆＃34;＆amp; key =（apiServerKey）＆＃34; urlString = urlString.stringByAddingPercentEscapesUsingEncoding（NSUTF8StringEncoding）！

    var placesTask = session.dataTaskWithURL(NSURL(string: urlString)!)

    if placesTask.taskIdentifier > 0 && placesTask.state == .Running {
        placesTask.cancel()
    }

    UIApplication.sharedApplication().networkActivityIndicatorVisible = true

    do{

        //******************Here's the line that displays error
        placesTask = session.dataTaskWithURL(NSURL(string: urlString)!) {
            (data, response, error) -> Void in
            UIApplication.sharedApplication().networkActivityIndicatorVisible = false
            //var placesArray = [GooglePlace]()
            do {
                if let json = try NSJSONSerialization.JSONObjectWithData(data!, options:[]) as? NSDictionary {
                    if let results = json["results"] as? NSArray {
                        for rawPlace:AnyObject in results {
                           // print(rawPlace)
                            var placename = ""
                            if let name = rawPlace["name"] as? NSString {
                                placename = name as String
                                self.locuri.insert(placename, atIndex: self.ct)
                                //self.locuri[ct] = placename

                            }
                            if let strada = rawPlace["vicinity"] as? NSString {
                                self.strazi.insert(strada as String, atIndex: self.ct)
                            }
                            if let iconurl = rawPlace["icon"] as? NSString {
                                self.iconuri.insert(iconurl as String, atIndex: self.ct)
                            }
                            if let placeid = rawPlace["place_id"] as? NSString {
                                self.placeiduri.insert(placeid as String, atIndex: self.ct)
                            }
                            self.ct++
                        }
                    }
                }
            } catch {
                //handle error
            }

        }


    }

    placesTask.resume()
}

这里这是我向tableview插入数据的方式和时间

func tableView（tableView：UITableView，cellForRowAtIndexPath indexPath：NSIndexPath） - ＆gt; UITableViewCell { if（tableView == self.tblNearby）{

        let cell2 = tableView.dequeueReusableCellWithIdentifier("mycell", forIndexPath: indexPath) as! MyCustomCellTableViewCell
        cell2.myTitleLabel.text = locuri[indexPath.row]
        cell2.StreetLabel.text = strazi[indexPath.row]
        if (iconuri.count != 0){
            if let url = NSURL(string: iconuri[indexPath.row]) {
                if let data = NSData(contentsOfURL: url){
                    //cell2.myImage.contentMode = UIViewContentMode.ScaleAspectFit
                    cell2.myImage.image = UIImage(data: data)
                }
            }
        }

Answer 1

你应该有一个看起来像这样的方法

    func loadPlaces() {
        startActivityIndicator()
        dataProvider.fetchPlacesNearCoordinate(coordinate, radius:searchRadius, types: searchedTypes) { places in

            dispatch_async(dispatch_get_main_queue()) {
                stopActivityIndicator()
               //append places object to your data
               self.tableView.reloadData()
            }

        }
    }

然而如果fetchPlacesNearCoordinate方法没有将clojure / completionBlock的调用分派给主队列，那么它应该看起来像这样

var d = [];
for (var i = 0; i < 3; i++) {
    d.push((function(i) {
        console.log('iterator: ' + i);
    }).bind(this, i));
}
d[0](); // iterator: 0
d[1](); // iterator: 1
d[2](); // iterator: 2

等待谷歌的地方请求

1 个答案: