How to adjust text label within iOS UIAlertView

Question

I have been trying hard to adjust label for my UIAlertView, and I am not successful. I want to make it resize correctly as per the string length. I read that there is not much one can do except to subclass it, but when I was about to do it, I found a trick to play with it. (code below)

I could successfully resize it, format fonts etc for small strings. I can fit some of my strings (<1000 chars) nicely, but larger strings (>1000 chars) make it ugly:

• Label just refuses to grow to fit extra content
• Text size does not reduce despite I reducing it (it gets reduced for smaller strings where it's not needed. And it remains bigger where it is needed smaller)
• The label shows with white background (the one seen in IB at design time) for larger strings, with trailing part of strings buried up because larger text.

The whole thing looks completely messed up.

Here is how I sneaked into UIAlertView appearance code:

-(void)willPresentAlertView:(UIAlertView *)alertView
{
    UILabel *body = [alertView valueForKey:@"_bodyTextLabel"]; 

    body.lineBreakMode = UILineBreakModeWordWrap;
    // body.adjustsFontSizeToFitWidth = YES;

    CGRect  alFrame = body.frame;

    CGFloat pointSize;

    UIFont * font = [UIFont fontWithName:@"Verdana" size:10];

    CGSize labelSize = [body.text sizeWithFont:font minFontSize:8   actualFontSize:&pointSize forWidth:alFrame.size.width  lineBreakMode:UILineBreakModeWordWrap];

    NSLog (@"%f", labelSize.height);
    UIFont *actualFont = [UIFont fontWithName:@"Verdana" size:10];
    CGSize sizeWithCorrectHeight = [body.text sizeWithFont:actualFont];

    alFrame.size.height = sizeWithCorrectHeight.height*10;
    NSLog (@"%f - %f", alFrame.size.height, alFrame.size.width);
    body.numberOfLines = 8;
    body.frame = alFrame;
    body.font = actualFont;    
}

Note that commented lines are things which I have tried with thousand twists. And uncommented ones too produce the same effect. Smaller text adjust just as I have coded here. I just need a solution that can make my label display all text, irrespective of string length - I know there is plenty of room on it still but it just doesn't resize for larger strings that's it.

Answer 1

Here is a hack that I have used successfully in many shipping apps.

1. Use sizeWithFont to figure out how much space you need (from the message text).
2. Set the message to an appropriate number of @"\n".
3. Insert a new transparent UILabel as a subview of the alert view with your text.

If you need really long texts, you could try inserting a UITextView, which theoretically can be scrolled. (Please tell me if it works if you try it.) However, I would strongly advise not to use this design and construct a proper view controller instead.

[alertView addSubview:label];

Answer 2

Firstly, you should not use the sizeWithFont... methods to calculate the size of your UILabels.

UILabel implements the standard UIKit sizeToFit and sizeThatFits: methods which you should use instead.

If you wish the label to wrap across multiple lines, first set numberOfLines to 0. Then use this code to calculate the required size:

CGSize requiredSize = [label sizeThatFits:CGSizeMake(availableWidth, CGFLOAT_MAX)];
labelFrame.size = requiredSize;
// ...

Alternatively, you can set the label's width first, then call [label sizeToFit]. It will size itself to fit its current width.