106设置滚动条的颜色（扩展知识：将滚动条设置为分页的形式）

效果如下：

ViewController.h

1 #import <UIKit/UIKit.h>

2 

3 @interface ViewController : UIViewController

4 @end

ViewController.m

 1 #import "ViewController.h"

 2 #import "KMLabelViewController.h"

 3 

 4 @interface ViewController ()

 5 - (void)layoutUI;

 6 @end

 7 

 8 @implementation ViewController

 9 #define kNumberOfPages 3

10 

11 - (void)viewDidLoad {

12     [super viewDidLoad];

13     

14     [self layoutUI];

15 }

16 

17 - (void)didReceiveMemoryWarning {

18     [super didReceiveMemoryWarning];

19     // Dispose of any resources that can be recreated.

20 }

21 

22 - (void)layoutUI {

23     CGFloat viewWidth = self.view.frame.size.width;

24     CGFloat viewHeight = self.view.frame.size.height;

25     

26     UIScrollView *scrVCustom = [[UIScrollView alloc] initWithFrame:self.view.bounds];

27     //为了能进行画面水平翻滚，设置滚动视图scrVCustom内容的水平长度

28     scrVCustom.contentSize = CGSizeMake(viewWidth * kNumberOfPages, viewHeight);

29     //设置是否以页为单位翻滚；默认值为NO

30     scrVCustom.pagingEnabled = YES;

31     //设置是否显示水平和垂直滚动条；默认值都为YES

32     scrVCustom.showsHorizontalScrollIndicator = YES;

33     scrVCustom.showsVerticalScrollIndicator = NO;

34     //设置是否允许滚动到顶部；默认值为YES

35     scrVCustom.scrollsToTop = NO;

36     

37     //设置滚动条的颜色

38     //UIScrollViewIndicatorStyleDefault（白色框包围黑色线条，大多数背景下适用）；默认值

39     //UIScrollViewIndicatorStyleBlack（黑色条）

40     //UIScrollViewIndicatorStyleWhite（白色条）

41     scrVCustom.indicatorStyle = UIScrollViewIndicatorStyleDefault;

42     

43     for (NSInteger i=0; i<kNumberOfPages; i++) {

44         KMLabelViewController *lblViewController = [[KMLabelViewController alloc] initWithNumber:i];

45         lblViewController.view.frame = CGRectMake(viewWidth * i, 0, viewWidth, viewHeight);

46         [scrVCustom addSubview:lblViewController.view];

47     }

48     [self.view addSubview:scrVCustom];

49 }

50 

51 @end

KMLabelViewController.h

1 #import <UIKit/UIKit.h>

2 

3 @interface KMLabelViewController : UIViewController

4 - (id)initWithNumber:(NSInteger)number;

5 

6 @end

KMLabelViewController.m

 1 #import "KMLabelViewController.h"

 2 

 3 @interface KMLabelViewController ()

 4 @end

 5 

 6 @implementation KMLabelViewController

 7 

 8 - (void)viewDidLoad {

 9     [super viewDidLoad];

10 }

11 

12 - (void)didReceiveMemoryWarning {

13     [super didReceiveMemoryWarning];

14     // Dispose of any resources that can be recreated.

15 }

16 

17 - (id)initWithNumber:(NSInteger)number {

18     if (self = [super init]) {

19         UILabel *lblCustom = [[UILabel alloc] initWithFrame:CGRectInset(self.view.bounds, 0, 0)];

20         lblCustom.text = [NSString stringWithFormat:@"%ld", (long)number];

21         lblCustom.textAlignment = NSTextAlignmentCenter;

22         lblCustom.textColor = [UIColor performSelector:NSSelectorFromString(number % 2 == 1 ? @"whiteColor" : @"blackColor")];

23         lblCustom.backgroundColor = [UIColor performSelector:NSSelectorFromString(number % 2 == 1 ? @"blackColor" : @"whiteColor")];

24         lblCustom.font = [UIFont boldSystemFontOfSize:64];

25         [self.view addSubview:lblCustom];

26     }

27     return self;

28 }

29 

30 @end