文字输入高亮状态的判断

WechatIMG8.jpeg

1.对需要做文字输入限制的textField添加监听(_nametext为需要添加监听的textfield)

 [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(textFiledEditChanged:)
                                                    name:@"UITextFieldTextDidChangeNotification"
                                                  object:_nametext];

2.实现监听(kMaxLength为限制字数)

-(void)textFiledEditChanged:(NSNotification *)obj{
    UITextField *textField = (UITextField *)obj.object;
    NSString *toBeString = textField.text;
    NSArray *currentar = [UITextInputMode activeInputModes];
    UITextInputMode *current = [currentar firstObject];
    if ([current.primaryLanguage isEqualToString:@"zh-Hans"]) { // 简体中文输入，包括简体拼音，健体五笔，简体手写
        UITextRange *selectedRange = [textField markedTextRange];
        //获取高亮部分
        UITextPosition *position = [textField positionFromPosition:selectedRange.start offset:0];
        // 没有高亮选择的字，则对已输入的文字进行字数统计和限制
        if (!position) {
            if (toBeString.length > kMaxLength) {
                textField.text = [toBeString substringToIndex:kMaxLength];
            }
        }
        // 有高亮选择的字符串，则暂不对文字进行统计和限制
        else{
            
        }
    }
    // 中文输入法以外的直接对其统计限制即可，不考虑其他语种情况
    else{
        if (toBeString.length > kMaxLength) {
            textField.text = [toBeString substringToIndex:kMaxLength];
        }
    }
}

3.不要忘记监听的移除

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:@"UITextFieldTextDidChangeNotification" object:nil];
}