UILabel is not auto-shrinking text to fit label size

Question

I have this strange issue, and im dealing with it for more than 8 hours now.. Depending on situation i have to calculate UILabels size dynamically,
e.g

Answer 1

Here's how to do it.Suppose the following messageLabel is the label you want to have the desired effect.Now,try these simple line of codes:

    //SET THE WIDTH CONSTRAINTS FOR LABEL.
    CGFloat constrainedWidth = 240.0f;//YOU CAN PUT YOUR DESIRED ONE,THE MAXIMUM WIDTH OF YOUR LABEL.
 //CALCULATE THE SPACE FOR THE TEXT SPECIFIED.
    CGSize sizeOfText=[yourText sizeWithFont:yourFont constrainedToSize:CGSizeMake(constrainedWidth, CGFLOAT_MAX) lineBreakMode:UILineBreakModeWordWrap];
    UILabel *messageLabel=[[UILabel alloc] initWithFrame:CGRectMake(20,20,constrainedWidth,sizeOfText.height)];
    messageLabel.text=yourText;
    messageLabel.numberOfLines=0;//JUST TO SUPPORT MULTILINING.