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[iOS]UITextView 输入字数限制

程序员文章站 2022-03-21 13:13:43
- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text { return textView.text.length + (text.length - range.length) <= 30;}...

 1.超过长度的字符不允许输入

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text {
    return textView.text.length + (text.length - range.length) <= 30;
}

2.输入后截取指定长度字符串

// 监听键盘
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textChangeAction:) name:UITextViewTextDidChangeNotification object:nil];

- (void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}
- (void)textChangeAction:(NSNotification*)notf {
    [self textViewMaxTextCount:self.inputTextView AndMaxCount:200];
}

// UITextView字数限制
- (void)textViewMaxTextCount:(UITextView *)textView AndMaxCount:(NSInteger)maxCount {
    NSString *toBeString = textView.text;
    NSString *lang = [[UIApplication sharedApplication] textInputMode].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 > maxCount) {
                textView.text = [toBeString substringToIndex:maxCount];
                [MBProgressHUD showError:[NSString stringWithFormat:@"字数不能超过%ld字",(long)maxCount]];
            }
        } 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 > maxCount) {
            textView.text = [toBeString substringToIndex:maxCount];
            [MBProgressHUD showError:[NSString stringWithFormat:@"字数不能超过%ld字",(long)maxCount]];
        }
    }
    _alertLab.text = [NSString stringWithFormat:@"%lu/%ld字",(unsigned long)textView.text.length,(long)_dataModel.limitNum];
}

 

本文地址:https://blog.csdn.net/u012881779/article/details/100584008

相关标签: [iOS]学习笔记