问题
How to hide the placeholder of TextField programmatically using Swift 3x ?
回答1:
You can not hide the placeholder of UITextField, but you can set it to empty String.
self.textField.placeholder = ""
Now textField doesn't show any placeholder later on if you want to show the placeholder simply set it with String that you want.
self.textField.placeholder = "Enter name"
来源：https://stackoverflow.com/questions/41421850/hide-placeholder-programatically-using-swift-3x