如何在Swift3中的另一个函数之后运行一个函数-HowtorunafunctionafteranotherfunctioninSwift3

2  

Try with this, as I said in my first comment I think you only need call self.tableView.reloadData after print(self.shopItems)

试试这个,正如我在第一篇评论中所说,我认为你只需要在打印后调用self.tableView.reloadData(self.shopItems)

self.shopItems = [String]()
databaseRef.observe(FIRDataEventType.value, with: { (snapshot) in
    for child in snapshot.children {
        let snap = child as! FIRDataSnapshot
        let dictiOnary= snap.value as! [String: AnyObject]
        self.shopItems.append(dictionary["Name"] as! String)

        print(self.shopItems)
    }
    self.tableView.reloadData()
})

And correctly implement this method

并正确实现此方法

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return self.shopItems.count
}

Also update your cellForRow to this

还要将cellForRow更新为此

 func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    var cell = tableView.dequeueReusableCell(withIdentifier: 
    self.cellReuseIdentifier, for: indexPath) as UITableViewCell

    cell.textLabel?.text = self.shopItems[indexPath.row]
    return cell
}

Hope this helps

希望这可以帮助

1  

You are badly confused. You don't call tableView(_:cellForRowAt:). The system calls it.

你非常困惑。你不要调用tableView(_:cellForRowAt :)。系统调用它。

If you want to wait and reload your table once the data has finished loading, you should put a call to reloadData inside your databaseRef.observe method's closure:

如果要在数据加载完成后等待并重新加载表,则应在databaseRef.observe方法的闭包内调用reloadData:

    databaseRef.observe(FIRDataEventType.value, with: { (snapshot) in
            for child in snapshot.children {
                let snap = child as! FIRDataSnapshot
                let dictiOnary= snap.value as! [String: AnyObject]
                self.shopItems.append(dictionary["Name"] as! String)

                print(self.shopItems)

                //Add the line below. 
                //Note that if the closure is called from the background, you'll 
                //need to use GCD to call this method on the main thread.
        }
        self.tableView.reloadData()
    }

And, if the completion code in your databaseRef.observe method gets called on a background thread then you'll need to wrap that in a call to Dispatch.main.async() (or a similar method to invoke the code on the main thread.)

并且,如果在后台线程上调用databaseRef.observe方法中的完成代码,则需要在调用Dispatch.main.async()时调用它(或者在主线程上调用代码的类似方法) 。)

DispatchQueue.main.async() {
    self.tableView.reloadData()
}

0  

The second function runs when data in the tableview is loaded. When the tableview is created it loads the data from shopitems array into the view. If there are no objects in the array the tableview will appear empty. In order to reflect changes to the shopitems array, in other words reflect that in item has been appended to the array you have to call the appropriate tableview function .

第二个函数在加载tableview中的数据时运行。创建tableview后,它会将shopitems数组中的数据加载到视图中。如果数组中没有对象,则tableview将显示为空。为了反映shopitems数组的更改,换句话说,反映在项目中已经附加到数组,您必须调用相应的tableview函数。

The correct way to do this is to use:

正确的方法是使用:

    databaseRef.observe(FIRDataEventType.value, with: { (snapshot) in
            for child in snapshot.children {
                let snap = child as! FIRDataSnapshot
                let dictiOnary= snap.value as! [String: AnyObject]
                self.shopItems.append(dictionary["Name"] as! String)

                let row = self.shopItems.index(of:self.shopItems.last!)
                let indexPath = IndexPath(row:row, section:0)
                tableView.insertItemsAtIndexPaths([indexPath])

                print(self.shopItems)
        }

    })

.You will have to create an indexPath using the index of the object in the shopitems array.

。您将必须使用shopitems数组中对象的索引创建indexPath。

The other method is to reload all the data in the tableview after append.

另一种方法是在追加后重新加载tableview中的所有数据。

    databaseRef.observe(FIRDataEventType.value, with: { (snapshot) in
            for child in snapshot.children {
                let snap = child as! FIRDataSnapshot
                let dictiOnary= snap.value as! [String: AnyObject]
                self.shopItems.append(dictionary["Name"] as! String)



                print(self.shopItems)
        }

              DispatchQueue.main.async {
            self.tableView.reloadData()
           }

    })