How do I size a UITextView to its content?

Is there a good way to adjust the size of a UITextView to conform to its content? Say for instance I have a UITextView that contains one line of text:

"Hello world"

I then add another line of text:

"Goodbye world"

Is there a good way in Cocoa Touch to get the rect that will hold all of the lines in the text view so that I can adjust the parent view accordingly?

As another example, look at the notes' field for events in the Calendar application - note how the cell (and the UITextView it contains) expands to hold all lines of text in the notes' string.

This works for both iOS 6.1 and iOS 7:

- (void)textViewDidChange:(UITextView *)textView
{
    CGFloat fixedWidth = textView.frame.size.width;
    CGSize newSize = [textView sizeThatFits:CGSizeMake(fixedWidth, MAXFLOAT)];
    CGRect newFrame = textView.frame;
    newFrame.size = CGSizeMake(fmaxf(newSize.width, fixedWidth), newSize.height);
    textView.frame = newFrame;
}

Or in Swift

let fixedWidth = textView.frame.size.width
let newSize = textView.sizeThatFits(CGSize(width: fixedWidth, height: CGFloat.greatestFiniteMagnitude))
textView.frame.size = CGSize(width: max(newSize.width, fixedWidth), height: newSize.height)

If you want support for iOS 6.1 then you should also:

textview.scrollEnabled = NO;

This no longer works on iOS 7 or above

There is actually a very easy way to do resizing of the UITextView to its correct height of the content. It can be done using the UITextView contentSize .

CGRect frame = _textView.frame;
frame.size.height = _textView.contentSize.height;
_textView.frame = frame;

One thing to note is that the correct contentSize is only available after the UITextView has been added to the view with addSubview . Prior to that it is equal to frame.size

This will not work if auto layout is ON. With auto layout, the general approach is to use the sizeThatFits method and update the constant value on a height constraint.

CGSize sizeThatShouldFitTheContent = [_textView sizeThatFits:_textView.frame.size];
heightConstraint.constant = sizeThatShouldFitTheContent.height;

heightConstraint is a layout constraint that you typically setup via a IBOutlet by linking the property to the height constraint created in a storyboard.

Just to add to this amazing answer, 2014, if you:

[self.textView sizeToFit];

there is a difference in behaviour with the iPhone6+ only:

With the 6+ only (not the 5s or 6) it does add "one more blank line" to the UITextView. The "RL solution" fixes this perfectly:

CGRect _f = self.mainPostText.frame;
_f.size.height = self.mainPostText.contentSize.height;
self.mainPostText.frame = _f;

It fixes the "extra line" problem on 6+.

To make a dynamically sizing UITextView inside a UITableViewCell , I found the following combination works in Xcode 6 with the iOS 8 SDK:

tableView.estimatedRowHeight = 150;
tableView.rowHeight = UITableViewAutomaticDimension;

For read-only dynamically sizing UITextView s, that's it. If you're allowing users to edit the text in your UITextView , you also need to:

- (void)textViewDidChange:(UITextView *)textView;
{
    [tableView beginUpdates];
    [tableView endUpdates];
}

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