UITextView的placehoder背景文字实现带并限制文字字数

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iOS textView 限制字数

1.在viewdidload中添加一个默认字体的lable

placeHoderLable = [[UILabel alloc]initWithFrame:CGRectMake(3, 3, DeviceWidth-6, 40)];//根据情况调节位置placeHoderLable.enabled = NO;placeHoderLable.text = @"请在这里输入您要预测的内容，您的预言需要经过其他用户的审核才能发布。";placeHoderLable.numberOfLines=0;placeHoderLable.font =  [UIFont systemFontOfSize:12];placeHoderLable.textColor = [UIColor lightGrayColor];[_myTextView addSubview:placeHoderLable];_myTextView.delegate=self;//记得设置textview的代理_myTextView.returnKeyType=UIReturnKeyDone;

2.在textview的代理方法中实现以下代码

-(void)textViewDidChange:(UITextView *)textView      {        if ([_myTextView.text length] == 0) {            [placeHoderLable setHidden:NO];        }else{            [placeHoderLable setHidden:YES];        }    }- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:                                (NSString *)text{    if([text isEqualToString:@"\n"]){        [textView resignFirstResponder];        return NO;    }    if (range.location>=100)    {        _yuNumLable.text=@"还能输入0字";        return  NO;    }    else    {        _yuNumLable.text=[NSString stringWithFormat:@"还能输入%lu字",100-range.location];        return YES;    }}

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