Swift Parse Query如何在對象中創建對象后使用uialertview？

Question

我正在解析查詢，並且想for object in objects {}完成后做UIAlertView！如果我將alertview放在for object in objects{//here}的for object in objects{//here} ，什么也沒發生，我怎么能檢測到何時出現for objects in objects {}完成后，我將顯示alertview？

代碼如下：

var query = PFUser.query()

query = PFQuery(className: "_User")

query.findObjectsInBackgroundWithBlock {

(object: [AnyObject]!, error:NSError?) -> Void in


for object in objects {

// alertview here not working, How can i make it after this loop done?


}

}

有什么幫助嗎？

Answer 1

var query = PFUser.query()

query = PFQuery(className: "_User")

// Heads up, entering background thread, may take some time to update the UI, maybe add an activity indicator even?
query.findObjectsInBackgroundWithBlock {

(objects: [AnyObject]?, error: NSError?) -> Void in

for object in objects as! [PFObject] {

// alertview here not working, How can i make it after this loop done?
// This would make an alert for every found object

}

// Anything after the for loop will happen after it completes, so if you put something here it will execute, suggest dispatching anything UI related to the main queue 

     dispatch_async(dispatch_get_main_queue(), { () -> Void in

        // visual interface stuff should happen here

    })

}