iOS: textField

关于在使用textfield的过程中,经常会遇到限制长度的要求,接下来说一下自己写的oc以及swift的用法:

例如:限制手机号输入框为11位

1.打开textfield的代理,然后在代理方法-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{

    if (range.length + range.location > textField.text.length){

         return NO;

}

    NSUInteger newLength = [textField.text length] + [string length] - range.length;

    return newLength <= 11;

}

Swift:

//手机号长度判断

func textField(textField: UITextField, shouldChangeCharactersInRange range: NSRange, replacementString string: String) -> Bool{

if (range.length + range.location > textField.text?.characters.count){

return false

}

let newLength:NSInteger = (textField.text?.characters.count)!+string.characters.count-range.length

return newLength<=11

}