Swift: UITextField IBAction - EditingChanged -按钮保持启用，即使textfield值被更改?

I have two IBActions for when two different text field's EditingChanged. Inside of these methods, I have an if statement that enables a button if two UITextFields both contain integers. The problem is, when the button becomes enabled, is stays enabled, even though if I edit the text field and change them so they have characters besides integers. How can I fix it? Please be thorough and clear when you provide the code because I am new to programming. Here's the code I have so far if you were wondering:I have two IBActions for when two different tex