macOS Limit textfield character length

[abcdefg12345]

I'm trying to limit character length in an app but i have no idea what I'm doing so i made a sample calculator app if anyone can add a code to it that limit how many characters u can inter in the field.

 

[LinusR]

I'm trying to limit character length in an app but i have no idea what I'm doing so i made a sample calculator app if anyone can add a code to it that limit how many characters u can inter in the field.

You can create a delegate referring to the specific NSTextField and overwrite the method

textShouldBeginEditing:

. It returns a bool, so you can either allow or disallow entering letters depending on how many characters have already been entered.