UITextView setContentSize does not work?

Question

I want to change my UITextView's content size, and I tried as below:

[self.textView setContentSize:CGSizeMake(self.textView.contentSize.width, self.textView.contentSize.height+30)];

I found it doesn't work. What's more, I make it in a button's click event to see what will happen.

- (IBAction)click:(id)sender {
    static int y = 0;
    UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0, y, 30, 30)];
    label.text = @"hello";
    y = y+30;
    [self.textView setContentSize:CGSizeMake(self.textView.contentSize.width, self.textView.contentSize.height+30)];
    NSLog(@"%f",self.textView.contentSize.height);
    [self.textView addSubview:label];
}

The result is the setContentSize doesn't work? What's more, contentSize just change for text content changing.

I want to know why, and Is there any method to change the UITextView's contentSize manually?

ADDITION: output for click action

2014-11-17 17:05:56.306 viewControllerAdvance[2371:607] 82.000000 
2014-11-17 17:05:56.455 viewControllerAdvance[2371:607] 82.000000
2014-11-17 17:05:56.638 viewControllerAdvance[2371:607] 82.000000
2014-11-17 17:05:56.772 viewControllerAdvance[2371:607] 82.000000
2014-11-17 17:05:56.923 viewControllerAdvance[2371:607] 82.000000
2014-11-17 17:05:57.072 viewControllerAdvance[2371:607] 82.000000

Answer 1

Try to modify your method like below and check whether it meets your requirement or not.To use below way you need to add your text view on a scroll view and whenever you increase text view's height you suppose to increase scroll view's content size

- (IBAction)click:(id)sender { 

     static int y = 0;
     UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(0, y, 30, 30)];
     label.text = @"hello";
     y = y+30;
     [self.textView addSubview:label];

     CGFloat fixedWidth = textView.frame.size.width;
     CGFloat dynamicHeight = textView.frame.size.height+30;

     CGSize newSize = [textView sizeThatFits:CGSizeMake(fixedWidth, dynamicHeight)];
     CGRect newFrame = textView.frame;
     newFrame.size = CGSizeMake(fixedWidth, fmaxf(newSize.height, dynamicHeight));
     textView.frame = newFrame;

 }

Also set textview.scrollEnabled = NO;