UISegmentedControl text with multiple lines?

问题:

How can I make the text in one of the buttons in my UISegmentedControl span multiple lines?

回答1:

Use UIAppearance to get things done. The below code snippet will work. Call this before creating your segment.

Objective-C

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

Swift

UILabel.appearanceWhenContainedInInstancesOfClasses([UISegmentedControl.self]).numberOfLines = 0

回答2:

I did it this way:

• create a multiline UILabel
• fill the label with N lines of text
• convert the label into an UIImage
• set the image as a segments content

This works smooth on iOS 4, 5, 6

and iOS 7 (just remove the text shadow)

MultiLineSegmentedControl - header file

//
//  MultiLineSegmentedControl.h
//
//  Created by Jens Kreiensiek on 20.07.11.
//  Copyright 2011 SoButz. All rights reserved.
//
#import <Foundation/Foundation.h>

@interface MultiLineSegmentedControl : UISegmentedControl
- (void)setMultilineTitle:(NSString *)title forSegmentAtIndex:(NSUInteger)segment;
@end

MultiLineSegmentedControl - implementation file

//
//  MultiLineSegmentedControl.m
//
//  Created by Jens Kreiensiek on 20.07.11.
//  Copyright 2011 SoButz. All rights reserved.
//
#import "MultiLineSegmentedControl.h"
#import "UIView+LayerShot.h"

@interface MultiLineSegmentedControl()
@property (nonatomic, retain) UILabel *theLabel;
@end

@implementation MultiLineSegmentedControl
@synthesize theLabel;

- (void)dealloc
{
    self.theLabel = nil;
    [super dealloc];
}


- (UILabel *)theLabel
{
    if (!self->theLabel) {

        self->theLabel = [[UILabel alloc] initWithFrame:CGRectZero];
        self->theLabel.textColor = [UIColor whiteColor];
        self->theLabel.backgroundColor = [UIColor clearColor];
        self->theLabel.font = [UIFont boldSystemFontOfSize:13];
        self->theLabel.textAlignment = UITextAlignmentCenter;
        self->theLabel.lineBreakMode = UILineBreakModeWordWrap;
        self->theLabel.shadowColor = [UIColor darkGrayColor];
        self->theLabel.numberOfLines = 0;
    }

    return self->theLabel;
}


- (void)setMultilineTitle:(NSString *)title forSegmentAtIndex:(NSUInteger)segment
{
    self.theLabel.text = title;
    [self.theLabel sizeToFit];

    [self setImage:self.theLabel.imageFromLayer forSegmentAtIndex:segment];
}

@end

UIView+LayerShot - header file

//
//  UIView+LayerShot.h
//
//  Created by Jens Kreiensiek on 29.06.12.
//  Copyright (c) 2012 SoButz. All rights reserved.
//
#import <UIKit/UIKit.h>

@interface UIView (LayerShot)
- (UIImage *)imageFromLayer;
@end

UIView+LayerShot - implementation file

//
//  UIView+LayerShot.m
//
//  Created by Jens Kreiensiek on 29.06.12.
//  Copyright (c) 2012 SoButz. All rights reserved.
//
#import "UIView+LayerShot.h"
#import <QuartzCore/QuartzCore.h>

@implementation UIView (LayerShot)

- (UIImage *)imageFromLayer
{
    UIGraphicsBeginImageContextWithOptions(self.bounds.size, NO, 0);
    [self.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

@end

Use it just like a normal UISegmentedControl:

...

MultiLineSegmentedControl *segment = [[MultiLineSegmentedControl alloc] 
    initWithItems:[NSArray arrayWithObjects:@"A", @"B", nil]];

segment.segmentedControlStyle = UISegmentedControlStyleBar;
segment.frame = CGRectMake(0, 0, 200, segment.frame.size.height * 1.5);

[segment setMultilineTitle:@"Title A\nSubtitle A" forSegmentAtIndex:0];
[segment setMultilineTitle:@"Title B\nSubtitle B" forSegmentAtIndex:1];

[self.view addSubview:segment];
[segment release];

...

回答3:

Swift 3+ syntax based on answer by @Saranya Sivanandham

UILabel.appearance(whenContainedInInstancesOf: [UISegmentedControl.self]).numberOfLines = 0

回答4:

The approach above is better, but for the sake of having an alternative, you can do something like:

for(UIView *subview in segmentedControl.subviews) {
        if([NSStringFromClass(subview.class) isEqualToString:@"UISegment"]) {
            for(UIView *segmentSubview in subview.subviews) {
                if([NSStringFromClass(segmentSubview.class) isEqualToString:@"UISegmentLabel"]) {
                    UILabel *label = (id)segmentSubview;
                    label.numberOfLines = 2;
                    label.text = @"Hello\nWorld";
                    CGRect frame = label.frame;
                    frame.size = label.superview.frame.size;
                    label.frame = frame;
                }
            }
        }
    }

回答5:

Years later...

     for segment in segmented.subviews{
        for label in segment.subviews{
            if let labels = label as? UILabel{
                labels.numberOfLines = 2

            }
        }
    }