TextView限制输入文字个数

TextField 、TextView限制输入文字个数-2019-01-03

- (void)textViewDidChange:(UITextView *)textView {
    //最大长度
    NSInteger kMaxLength = 300;
    NSString *toBeString = textView.text;
    NSString *lang = [[UIApplication sharedApplication]textInputMode].primaryLanguage; //ios7之前使用[UITextInputMode currentInputMode].primaryLanguage
    if ([lang isEqualToString:@"zh-Hans"]) { //中文输入
        UITextRange *selectedRange = [textView markedTextRange];
        //获取高亮部分
        UITextPosition *position = [textView positionFromPosition:selectedRange.start offset:0];
        if (!position) {// 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 (toBeString.length > kMaxLength) {
                textView.text = [toBeString substringToIndex:kMaxLength];
                [textView resignFirstResponder];
            }
        }
        else{//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
        if (toBeString.length > kMaxLength) {
            textView.text = [toBeString substringToIndex:kMaxLength];
        }
    }
}