How to use iOS UITextField

UITextField inherits from UIControl and has the related characteristics and methods of UIControl.

UITextField is a control used to accept user input. It can be created through code, xib, and storyboard. It has corresponding proxy methods:

- (void)viewDidLoad {
    [super viewDidLoad];
    self.accountTextF.delegate = self;
    [self.accountTextF addTarget:self action:@selector(textChanged) forControlEvents:UIControlEventEditingChanged];
    self.passWordTF.delegate = self;
    [self.passWordTF addTarget:self action:@selector(textChanged) forControlEvents:UIControlEventEditingChanged];
}

#pragma mark - 监测tf输入编辑事件

- (void)textChanged{
    if (self.accountTextF.text.length > 0 && self.passWordTF.text.length > 0) {
        self.loginButton.enabled = YES;
    }else{
        self.loginButton.enabled = NO;
    }
}

#pragma mark - TextFild delegate function

// 是否开始进入编辑状态
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
    return YES;
}

// 是否结束编辑状态
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField{
    return YES;
}

// 是否改变编辑的字符串(可用于判断是否允许输入)
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string{
    return YES;
}

// 是否清除
- (BOOL)textFieldShouldClear:(UITextField *)textField{
    return YES;
}

// 结束编辑时调用
- (void)textFieldDidEndEditing:(UITextField *)textField{
    
}

// 开始编辑时调用
- (void)textFieldDidBeginEditing:(UITextField *)textField{
    
}