我試圖用dispatch_group_notify發送一個HTTP請求,我需要等待繼續我的處理,此命令的結果。迅速使用異步請求dispatch_group_notify不起作用
這裏是下面的調用:
self.save(){(response) in
if let result = response as? Bool {
if(result == true){
dispatch_group_notify(self.myGroup!, dispatch_get_main_queue(), {
print("send carnet finished")
let registrationView = UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("carnetTable") as! CarnetTableViewController
self.navigationController?.pushViewController(registrationView, animated: true)
})
}
}
}
,這裏是誰在發送HTTP命令功能:
func save(callback: (AnyObject) ->()){
dispatch_group_enter(self.myGroup)
let p = pickerDataSource[patients.selectedRowInComponent(0)]
let params = "owner=\(User.sharedInstance.email)&patient=\(p)&carnet=\(commentaires.text!)"
let final_url = url_to_request + "?" + params.stringByAddingPercentEncodingForISOLatin1()!
print("URL addCarnet: \(final_url)")
let url:NSURL = NSURL(string: final_url)!
//let session = NSURLSession.sharedSession()
let configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: configuration,
delegate: self,
delegateQueue:NSOperationQueue.mainQueue())
let request = NSMutableURLRequest(URL: url)
request.HTTPMethod = "GET"
request.cachePolicy = NSURLRequestCachePolicy.ReloadIgnoringCacheData
request.timeoutInterval = 10
let task = session.dataTaskWithRequest(request) {
(
let data, let response, let error) in
guard let _:NSData = data, let _:NSURLResponse = response where error == nil else {
print("error data")
dispatch_group_leave(self.myGroup)
callback(false)
return
}
var result = NSString(data: data!, encoding:NSASCIIStringEncoding)!
print("result: \(result)")
}
task.resume()
dispatch_group_leave(self.myGroup)
callback(true)
}
我想確保保存功能完成前(dispatch_group_leave)打開新的ViewController(CarnetTableViewController),但我可以看到ViewController在dispatch_group結束之前調用...
我該怎麼做確保在打開新的View之前保存功能的結束?