ShareView | 一个高性能UI优化库，多个布局的管理器，用于多状态UI自由切换，View层的栈结构管理。

You need to use the sort comparator function instead of the comparator property. This allows you to specify a comparator function instead of just the property. For example;

Here is minimal working demo example

In the method button.addTarget(self, action: #selector(optionClicked(_:)), for: .touchUpInside) you need to provide pointer to the viewController which will receive the action.

The easiest way in your case would be to create lazy variable DrawerView with DrawerController on the init and use the drawer controller in the button action.

DrawerView.swift

The .observe(.childAdded) method actually returns the entire set of objects under a node when it is invoked for the first time, and then returns newly added objects thereafter.

Also, a Firebase DB observer is not like a normal API call which you hit by calling it. You have called the observe method for "messages" multiple times in your code. Instead, call the observer just once. A good way to implement this can be to invoke observer in your didLoad just once. It will trigger everytime you perform a change, like deleting an entry.

Also perform the append logic there and reload the tableview in didSet for the questions array. Makes the whole approach a tad bit reactive.

So the root cause for your duplicate entries is that when you add an object, both of your observers in trailingSwipeActionsConfigurationForRowAt and didLoad fire, both appending to the same array.

Also structure your code a bit. It would really help you once you start adding more functionality to your app.

You can use bellow code to fetch address base on latlong

You have to put the delegate method in the ViewController but not in the tableView:didSelectRowAt method:

Your else if indexPath.row == 2 is indented one level too deeply – its else refers to !MFMailComposeViewController.canSendMail(), not the previous indexPath check. You'll need to shift that branch outwards one level to get the effect you want.

For the future, it might be easier to debug if you refactor out a single method for all your mail-composing:

If the problem is likely has something to do with XML namespaces then you really should not omit the namespaces part of your XML form the question since it is fundamental for diagnosing the problem and for writing a working solution.

I suspect the namespace http://tableau.com/api was declared as a default namespaces (the one without prefix) in the XML, in which case all descendant elements without prefix implicitly inherit the same namespace from the ancestor. This would explain why granteeCapabilities didn't work for you, and you should try to add the prefix t here as well :