UITextView计算字数 限制字数

要做字数限制，网上看了一些，都不是很好用，要不就是不能同时兼顾ios6,7 。在textViewDidChange：事件进行添加

- (void)textViewDidChange:(UITextView *)textView{if(![textView markedTextRange]){if(textView.text.length > 20){UIAlertView *alter_view = [[UIAlertView alloc] initWithTitle:@"内容过长" message:nil delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];[alter_view show];textView.text = [textView.text substringToIndex:20];}NSLog(@"%@",[NSString stringWithFormat:@"%d/20",textView.text.length]);//_label_textCount.text = [NSString stringWithFormat:@"%d/20",textView.text.length];}}

另外附上点击回收键盘

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{if ([text isEqualToString:@"\n"] && ![textView markedTextRange]){[textView resignFirstResponder];return NO;}return YES;}