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）

1 #import <UIKit/UIKit.h>
2 
3 @interface ViewController : UIViewController
4 @end

 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

1 #import <UIKit/UIKit.h>
2 
3 @interface KMLabelViewController : UIViewController
4 - (id)initWithNumber:(NSInteger)number;
5 
6 @end

 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