uitextview 字數限制

不多說了，這只是簡單的判斷長度了，沒區分中英文等

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{
    NSInteger number ;
    number = [textView.text length]+text.length;
    
    if (number > 25) {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"字符個數不能大於25" delegate:self cancelButtonTitle:@"確定" otherButtonTitles:nil];
        [alert show];
        
        textView.text = [NSString stringWithFormat:@"%@%@",textView.text,text];
        textView.text = [textView.text substringToIndex:25];

        return NO;
    }else{
        if (number>25) {
            return NO;
        }else
            return YES;
    }
    
}