How to resize text (font) to fit in UISegment of UISegmentedControl?

I found the issue, Actually it was my mistake!!! I was setting numberOfLines,adjustsFontSizeToFitWidth,minimumScaleFactor and TitleTextAttributes toghether. If we set titleTextAttribute then minimumScaleFactor can't work.

Update : (As asked by @HawkEye1194 in comment of another answer)

I have end up with below solution,

 //this will allow multiple lines in label contained by every segment in segmentedcontroller

[[UILabel appearanceWhenContainedIn:[UISegmentedControl class], nil] setNumberOfLines:0];


UISegmentedControl *segment = [[UISegmentedControl alloc]initWithItems:option];
segment.frame = CGRectMake(20, 50, self.view.frame.size.width - 40, 50);
segment.tintColor = [UIColor grayColor];
segment.selectedSegmentIndex = 0;
segment.backgroundColor = [UIColor whiteColor];
segment.tag = segmentedControllerBaseTag;


[segment addTarget:self action:@selector(segmentChanged:) forControlEvents:UIControlEventValueChanged];

[segment setTitleTextAttributes:@{NSFontAttributeName :[UIFont fontWithName:@"HelveticaNeue" size:17.0], NSForegroundColorAttributeName : [UIColor darkGrayColor] } forState:UIControlStateNormal];
[segment setTitleTextAttributes:@{NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue" size:17.0],NSForegroundColorAttributeName : [UIColor whiteColor]} forState:UIControlStateSelected];

If your not setting title textattribute as above then you can use below code

// ********** if titletextattributes are not set then below method works ***********

   for(uint i=0;i<[segment subviews].count;i++)
   {
    for(UIView *view in [[[segment subviews] objectAtIndex:i] subviews])
    {
        if([view isKindOfClass:[UILabel class]])
        {

            [(UILabel*)view setNumberOfLines:0];
            [(UILabel*)view setAdjustsFontSizeToFitWidth:YES];
            [(UILabel*)view setMinimumScaleFactor:0.7];


        }
    }
}

You can adjust single segment's size as per it's content by below code,

 //*************** adjust single segment size as per content

 segment.apportionsSegmentWidthsByContent = YES;

Try this, I hope this will help you and you will get an idea how this works-

I have a UISegmentedControl i.e. _userProfileSagmentOutlet having three segments. Here is sample code-

CGFloat fontSize = 15;

[_userProfileSagmentOutlet setTitleTextAttributes:@{NSFontAttributeName:[UIFont fontWithName:@"Roboto-medium" size:fontSize],
                                                    NSForegroundColorAttributeName:[UIColor whiteColor]}
                                         forState:UIControlStateSelected];

[_userProfileSagmentOutlet setTitleTextAttributes:@{NSFontAttributeName:[UIFont fontWithName:@"Roboto-medium" size:fontSize],
                                                    NSForegroundColorAttributeName:[UIColor whiteColor]}
                                         forState:UIControlStateNormal];

this is the previous code which truncate tail of title like below image-

here is the main logic which fit each title in segments with same font size-

CGFloat fontSize = 15;

NSAttributedString* firstTitle = [[NSAttributedString alloc] initWithString:@"Membership History" attributes:@{NSFontAttributeName: [UIFont fontWithName:@"Roboto-medium" size:fontSize]}];

NSAttributedString* secondTitle = [[NSAttributedString alloc] initWithString:@"Event History" attributes:@{NSFontAttributeName: [UIFont fontWithName:@"Roboto-medium" size:fontSize]}];

NSAttributedString* thirdTitle = [[NSAttributedString alloc] initWithString:@"Booked Classes" attributes:@{NSFontAttributeName: [UIFont fontWithName:@"Roboto-medium" size:fontSize]}];


float maxW=MAX(MAX(firstTitle.size.width, secondTitle.size.width), thirdTitle.size.width);

while (maxW > _userProfileSagmentOutlet.subviews[0].frame.size.width) {

    fontSize--;

    firstTitle = [[NSAttributedString alloc] initWithString:@"Membership History" attributes:@{NSFontAttributeName: [UIFont fontWithName:@"Roboto-medium" size:fontSize]}];

    secondTitle = [[NSAttributedString alloc] initWithString:@"Event History" attributes:@{NSFontAttributeName: [UIFont fontWithName:@"Roboto-medium" size:fontSize]}];

    thirdTitle = [[NSAttributedString alloc] initWithString:@"Booked Classes" attributes:@{NSFontAttributeName: [UIFont fontWithName:@"Roboto-medium" size:fontSize]}];

    maxW=MAX(MAX(firstTitle.size.width, secondTitle.size.width), thirdTitle.size.width);


}
[_userProfileSagmentOutlet setTitleTextAttributes:@{NSFontAttributeName:[UIFont fontWithName:@"Roboto-medium" size:fontSize],
                                                    NSForegroundColorAttributeName:[UIColor whiteColor]}
                                         forState:UIControlStateSelected];

[_userProfileSagmentOutlet setTitleTextAttributes:@{NSFontAttributeName:[UIFont fontWithName:@"Roboto-medium" size:fontSize],
                                                    NSForegroundColorAttributeName:[UIColor whiteColor]}
                                         forState:UIControlStateNormal];

after using this code image look like this(same font size and text fit to segment and works fine)-

Here is Swift extension if someone needed-

    var fontSize:CGFloat = 15.0;

    var firstTitle = NSMutableAttributedString.init(string: "Membership History", attributes:[NSFontAttributeName: UIFont.systemFontOfSize(fontSize)])

    var secondTitle = NSMutableAttributedString.init(string: "Events History" ,attributes:[NSFontAttributeName: UIFont.systemFontOfSize(fontSize)]);

    var thirdTitle = NSMutableAttributedString.init(string: "Booked Classes" ,attributes:[NSFontAttributeName: UIFont.systemFontOfSize(fontSize)]);

    var maxW:CGFloat = max(max(firstTitle.size().width, secondTitle.size().width), thirdTitle.size().width);

    while (maxW > userProfileSagmentOutlet.subviews[0].frame.size.width) {

        fontSize--;

         firstTitle = NSMutableAttributedString.init(string: "Membership History", attributes:[NSFontAttributeName: UIFont.systemFontOfSize(fontSize)])

         secondTitle = NSMutableAttributedString.init(string: "Events History" ,attributes:[NSFontAttributeName: UIFont.systemFontOfSize(fontSize)]);

         thirdTitle = NSMutableAttributedString.init(string: "Booked Classes" ,attributes:[NSFontAttributeName: UIFont.systemFontOfSize(fontSize)]);

         maxW = max(max(firstTitle.size().width, secondTitle.size().width), thirdTitle.size().width);

    }
    userProfileSagmentOutlet.setTitleTextAttributes([NSFontAttributeName: UIFont.systemFontOfSize(fontSize),NSForegroundColorAttributeName:UIColor.whiteColor()], forState:UIControlState.Normal)

    userProfileSagmentOutlet.setTitleTextAttributes([NSFontAttributeName: UIFont.systemFontOfSize(fontSize),NSForegroundColorAttributeName:UIColor.whiteColor()], forState:UIControlState.Selected)

SWIFT 4

allow multiple lines in label

if #available(iOS 9.0, *) {
    UILabel.appearance(whenContainedInInstancesOf: [UISegmentedControl.self]).numberOfLines = 0
}