095实现一个播放器的活动指示器

效果如下：

ViewController.h

1 #import <UIKit/UIKit.h>
2
3 @interface ViewController : UIViewController
4 @property (strong, nonatomic) UIActivityIndicatorView *activityIndicatorView;
5
6 @end

ViewController.m

 1 #import "ViewController.h"
 2
 3 @interface ViewController ()
 4 - (void)layoutUI;
 5 - (void)playDidPush:(UIBarButtonItem *)sender;
 6 - (void)pauseDidPush:(UIBarButtonItem *)sender;
 7 - (void)changeDidPush:(UIBarButtonItem *)sender;
 8 @end
 9
10 @implementation ViewController
11
12 - (void)viewDidLoad {
13     [super viewDidLoad];
14
15     [self layoutUI];
16 }
17
18 - (void)didReceiveMemoryWarning {
19     [super didReceiveMemoryWarning];
20     // Dispose of any resources that can be recreated.
21 }
22
23 - (void)viewWillAppear:(BOOL)animated {
24     [super viewWillAppear:animated];
25     [self.navigationController setNavigationBarHidden:NO animated:animated];
26     [self.navigationController setToolbarHidden:NO animated:animated];
27 }
28
29 - (void)layoutUI {
30     self.view.backgroundColor = [UIColor lightGrayColor];
31     self.navigationItem.title = @"实现一个播放器的活动指示器";
32
33     UIBarButtonItem *barBtnPlay = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemPlay target:self action:@selector(playDidPush:)];
34     UIBarButtonItem *barBtnPause = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemPause target:self action:@selector(pauseDidPush:)];
35     UIBarButtonItem *barBtnFastForward = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemFastForward target:self action:@selector(changeDidPush:)];
36     [self setToolbarItems:@[barBtnPlay, barBtnPause, barBtnFastForward]];
37
38     //设置活动指示器视图
39     _activityIndicatorView = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleWhiteLarge]; //设置活动指示器视图样式；默认值是UIActivityIndicatorViewStyleWhite，设置的枚举值决定了活动指示器loading图片的宽高大小
40     _activityIndicatorView.layer.borderColor = [UIColor redColor].CGColor;
41     _activityIndicatorView.layer.borderWidth = 2.0;
42     [self.view addSubview:_activityIndicatorView];
43
44     /* 官方定义内容，仅供查看
45      typedef NS_ENUM(NSInteger, UIActivityIndicatorViewStyle) {
46         UIActivityIndicatorViewStyleWhiteLarge,
47         UIActivityIndicatorViewStyleWhite,
48         UIActivityIndicatorViewStyleGray,
49     };
50      */
51 }
52
53 - (void)playDidPush:(UIBarButtonItem *)sender {
54     if (_activityIndicatorView.activityIndicatorViewStyle == UIActivityIndicatorViewStyleWhiteLarge) {
55         _activityIndicatorView.frame = CGRectMake(0, 0, 100, 100);
56     } else {
57         _activityIndicatorView.frame = CGRectMake(0, 0, 50, 50);
58     }
59     _activityIndicatorView.center = self.view.center;
60     [_activityIndicatorView startAnimating];
61 }
62
63 - (void)pauseDidPush:(UIBarButtonItem *)sender {
64     _activityIndicatorView.hidesWhenStopped = NO; //设置活动指示器视图是否停止后隐藏；默认值是YES
65     [_activityIndicatorView stopAnimating];
66 }
67
68 - (void)changeDidPush:(UIBarButtonItem *)sender {
69     [self pauseDidPush:sender];
70     if (++_activityIndicatorView.activityIndicatorViewStyle > UIActivityIndicatorViewStyleGray) {
71         _activityIndicatorView.activityIndicatorViewStyle = UIActivityIndicatorViewStyleWhiteLarge;
72     }
73     [self playDidPush:sender];
74 }
75
76 @end

AppDelegate.h

1 #import <UIKit/UIKit.h>
2
3 @interface AppDelegate : UIResponder <UIApplicationDelegate>
4 @property (strong, nonatomic) UIWindow *window;
5 @property (strong, nonatomic) UINavigationController *navigationController;
6
7 @end

AppDelegate.m

 1 #import "AppDelegate.h"
 2 #import "ViewController.h"
 3
 4 @interface AppDelegate ()
 5 @end
 6
 7 @implementation AppDelegate
 8
 9 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
10     _window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
11     ViewController *viewController = [[ViewController alloc] init];
12     _navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
13     _window.rootViewController = _navigationController;
14     //[_window addSubview:_navigationController.view]; //当_window.rootViewController关联时，这一句可有可无
15     [_window makeKeyAndVisible];
16     return YES;
17 }
18
19 - (void)applicationWillResignActive:(UIApplication *)application {
20 }
21
22 - (void)applicationDidEnterBackground:(UIApplication *)application {
23 }
24
25 - (void)applicationWillEnterForeground:(UIApplication *)application {
26 }
27
28 - (void)applicationDidBecomeActive:(UIApplication *)application {
29 }
30
31 - (void)applicationWillTerminate:(UIApplication *)application {
32 }
33
34 @end