placeHoderLable = [[UILabel alloc]initWithFrame:CGRectMake(3, 3, DeviceWidth-6, 40)];
//根据情况调节位置 placeHoderLable.enabled = NO;
placeHoderLable.text = @"请在这里输入您要的内容，您的预言需要经过其他用户的才能发布。";
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;
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:@" "]){
[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;
}
}