self.mTextView =[[UITextView alloc]initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH - 100, 28)];

    self.mTextView.backgroundColor =[UIColor whiteColor];

    self.mTextView.delegate = self;

    self.mTextView.text = @"我来说几句....";

    [self.mSecondaryBackView addSubview:self.mTextView];

 

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(textDidChanged:) name:UITextViewTextDidChangeNotification object:nil];

 

- (void)textDidChanged:(NSNotification *)notif //监听文字改变 换行时要更改输入框的位置

{

    CGSize contentSize = self.mTextView.contentSize;

    UILabel *holdPlace = (UILabel *)[self.mTextView viewWithTag:1500];

    if (holdPlace) {

            holdPlace.text = @"";

    }

   

    if (contentSize.height > 140){

        return;

    }

    CGFloat minus = 3;

    CGRect selfFrame = self.mBackView.frame;

    CGFloat selfHeight = self.mTextView.superview.frame.origin.y * 2 + contentSize.height - minus + 2 * 2;

    CGFloat selfOriginY = selfFrame.origin.y - (selfHeight - selfFrame.size.height);

    selfFrame.origin.y = selfOriginY;

    selfFrame.size.height = selfHeight;

    self.mBackView.frame = selfFrame;

    self.mSecondaryBackView.frame =CGRectMake(10, 10, 230, selfHeight-20);

    NSLog(@"文字改变");

}