Alert instead of keyboard for input in textfield --> cursor stays in textfield Swift2

Question

I'm attempting to make an alert the input view for a textfield, since i have max. 3 choices to make and my customer wants to have it look this way.

Basically no problem, i can tap on the textfield, resulting in showing the alert. After choosing the value in the textfield gets updated correctly, but then, the cursor stays in the textfield (im assuming because of the tap, the textfield is first responder)

The problem now is, when i tap on that very same textfield again while the cursor is in it, the default keyboard opens. So what can i do to stop it from doing this?

I have tried the following things on various locations in code:

resignFirstResponder()
becomeFirstResponder()

Also, when im currently editing another textfield with the keyboard, im able to show the alert when tapping the corresponding textfield. this results in the keyboard covering the alert, since im also not able to close the keyboard when this occurs.

Attempt against this: (Written in Event methods of other textfields

    if (alertView != nil) {
        alertView?.dismiss()
    } //Not very professional, but still in development :)

Here are some important code snippets to understand how i built it up:

This function is the EditingDidBegin Event of the textfield

@IBAction func TextboxUnitEditing(sender: UITextField) {
    //One try of preventing the cursor (not working)
    tableView.endEditing(true)

    ...
    /* Unrelated Code here */
    ...

    alertView = SwiftAlertView(...)

            ...
    /* Unrelated Code here */
    ...

    alertView.show()
}

Delegate method of the alert

func alertView(alertView: SwiftAlertView, clickedButtonAtIndex buttonIndex: Int) {
    //buttonIndex == 1 means, cancel was tapped
    if (buttonIndex == -1) {
        currentCell = nil
        tableView.endEditing(true)
        return
    }

    ...
    /* Change value in textfield */
}

So my question is, what goes wrong? What do i need to call to get rid of the cursor? If there is anything more you need to know, please tell me and i can provide more information.

Thanks in advance.

EDIT:

Solved. Instead of:

    self.tableView.endEditing(true)

i had to do this:

    dispatch_async(dispatch_get_main_queue(),{
        self.tableView.endEditing(true)
    })

Answer 1

Instead of

self.tableView.endEditing(true)

It has to be done on the main thread

dispatch_async(dispatch_get_main_queue(),{
    self.tableView.endEditing(true)
})

Otherwise this line will be skipped