无法将UITextView调整为其内容的大小

Question

Here's the code for a UITextView that I want to size to the height of its content.

If I write the textView.frame height explicitly like:

    textView.frame = CGRectMake(100, 12, 320, 458);

the textView sizes to it's content as expected.

If, however, I write it like the following. It doesn't even display although the NSLog statement says that there's a value to textView.contentSize.height

UITextView *textView = [[UITextView alloc] init];
textView.layer.borderWidth = 5.0f;

textView.layer.borderColor = [[UIColor redColor] CGColor];

textView.text = [item objectForKey:@"description"];

textView.frame = CGRectMake(100, 12, 320, textView.contentSize.height);


NSLog(@"%f textviewcontnet size", textView.contentSize.height);

textView.editable = NO;

[self.view addSubview:textView];

When I log the output of:

NSLog(@"%f textviewcontent size", textView.contentSize.height);

I get "458.000000 textviewcontent size"

thanks for any help

Answer 1

I'd suggest trying:

UITextView *textView = [[UITextView alloc] init];
textView.layer.borderWidth = 5.0f;
textView.layer.borderColor = [[UIColor redColor] CGColor];
textView.text = [item objectForKey:@"description"];
textView.frame = CGRectMake(100, 12, 320, 458);    
textView.editable = NO;

[self.view addSubview:textView];

textView.frame = CGRectMake(100, 12, 320, textView.contentSize.height);    

I've heard that textView.contentSize.height doesn't work until it's been added to a view (though that's not my experience). More importantly, I don't know how it would interpret textView.contentSize.height if it doesn't yet know what the width of the control is. So go ahead, set the initial frame , do addSubview and then readjust the size based upon textView.contentSize.height .

Answer 2

Quickly copied out of one of my projects:

AppDelegate *appDelegate;

CGSize  textSize1, textSize2;

appDelegate = (AppDelegate*)[[UIApplication sharedApplication] delegate];

textSize1 = [self.subjectLabel.text sizeWithFont:[appDelegate fontNormal] constrainedToSize:CGSizeMake(300.0f, 10000.0f) lineBreakMode:NSLineBreakByWordWrapping];
self.subjectLabel.frame = CGRectMake(10, 5, 300, textSize1.height);
textSize2 = [self.descriptionLabel.text sizeWithFont:[appDelegate fontNormal] constrainedToSize:CGSizeMake(300.0f, 10000.0f) lineBreakMode:NSLineBreakByWordWrapping];
self.descriptionLabel.frame = CGRectMake(10, 5 + textSize1.height + 5, 300, textSize2.height);

[appDelegate fontNormal] just returns a UIFont object, the one that I am using for all "normal" text items. Don't worry about that too much. But it is important that you use the same font that is used for the text view too.

My example is a bit easier because it is a UILable. That works with a text view too but you will have to consider the insects. Easy solution, just substract some "fuzzy offset" from the width compared to the frame width of your text view.