iOS 多个window叠加

window，多个时，[UIApplication sharedApplication].windows[0]和[[UIApplication sharedApplication] delegate] window]获取的是最开始创建的window，而[UIApplication sharedApplication].keyWindow获取的是当前显示的window,不一定是最初的window。window之间的切换时可以的，让不需要出现的window隐藏，不过只有当前显示的window才能响应事件，window隐藏，它上面所添加的VIew都会隐藏。就是window不隐藏，它后面有window添加，那么相当于开始的是隐藏的，它上面的东西不会显示出来。

直接怼代码：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Override point for customization after application launch.
    
    wgj01ViewController *mainTabBarController = [[wgj01ViewController alloc] init];
    UINavigationController *naBar = [[UINavigationController alloc] initWithRootViewController:mainTabBarController];
    
    self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
    self.window.rootViewController = naBar;
    [self.window makeKeyAndVisible];
    
    NSLog(@"root1N:%@,,root1VC:%@",naBar,mainTabBarController);
    
    self.secondWindow = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
    wgj02ViewController *secondVC = [[wgj02ViewController alloc] init];
    self.secondWindow.rootViewController = secondVC;
    [self.secondWindow makeKeyAndVisible];
    self.secondWindow.backgroundColor = [UIColor orangeColor];
//    [self.window addSubview:self.secondWindow];
    
    NSLog(@"root2:%@",secondVC);
    
     NSLog(@"keyW:%@", [UIApplication sharedApplication].keyWindow);
    NSLog(@"windows:count:%ld,具体：%@\n%@",[UIApplication sharedApplication].windows.count ,[UIApplication sharedApplication].windows[0],[UIApplication sharedApplication].windows[1]);
    
    NSLog(@"\n\n\ndelegateW:%@\n%@", [[[UIApplication sharedApplication] delegate] window],[UIApplication sharedApplication].windows[0].rootViewController);
    
    return YES;
}

#import "wgj01ViewController.h"
#import "wgj01push1.h"

@implementation wgj01ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(10, 50, 200, 50)];
    button.backgroundColor = [UIColor orangeColor];
    [button setTitle:@"wgj01ViewControllerAddView" forState:(UIControlStateNormal)];
    [button addTarget:self action:@selector(clickBtn) forControlEvents:(UIControlEventTouchUpInside)];
    [self.view addSubview:button];
    
    
    UIButton *button1 = [[UIButton alloc] initWithFrame:CGRectMake(10, 250, 200, 50)];
    button1.backgroundColor = [UIColor orangeColor];
    [button1 setTitle:@"wgj01ViewControllerPush" forState:(UIControlStateNormal)];
    [button1 addTarget:self action:@selector(clickBtnPush) forControlEvents:(UIControlEventTouchUpInside)];
    [self.view addSubview:button1];
}

- (void)clickBtn
{
    NSLog(@"点击了wgj01ViewController");
    NSLog(@"\n\nself.view.window:%@\n,keyWindow:%@\n,delegateWindow:%@\n,count:%lu\n\n%@\n%@\n",self.view.window,[UIApplication sharedApplication].keyWindow,[[[UIApplication sharedApplication] delegate] window],(unsigned long)[UIApplication sharedApplication].windows.count,[UIApplication sharedApplication].windows[0],[UIApplication sharedApplication].windows[1]);
    
    
    UIView *coverV = [[UIView alloc] initWithFrame:CGRectMake(10, 10, 100, 100)];
    coverV.backgroundColor = [UIColor redColor];
    [[UIApplication sharedApplication].windows[0] addSubview:coverV];
    
    
}

- (void)clickBtnPush
{
    wgj01push1 *ss = [[wgj01push1 alloc] init];
    [self.navigationController pushViewController:ss animated:YES];
    
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
@end

\#import "wgj02ViewController.h"

@implementation wgj02ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(10, 150, 200, 50)];
    button.backgroundColor = [UIColor orangeColor];
    [button setTitle:@"wgj02ViewController" forState:(UIControlStateNormal)];
    [button addTarget:self action:@selector(clickBtn) forControlEvents:(UIControlEventTouchUpInside)];
    [self.view addSubview:button];
}

- (void)clickBtn
{
//    UIView *coverV = [[UIView alloc] initWithFrame:CGRectMake(10, 10, 100, 100)];
//    coverV.backgroundColor = [UIColor redColor];
//    [[UIApplication sharedApplication].windows[0] addSubview:coverV];
//    
//    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
        NSLog(@"点击了wgj02ViewController");
        NSLog(@"\n\n%@",self.view.window);
        [self.view.window resignKeyWindow];
        NSLog(@"%@,%@",[[[UIApplication sharedApplication] delegate] window],[UIApplication sharedApplication].keyWindow  );
        
        self.view.window.hidden = YES;
        
        NSLog(@"%@,%@",[[[UIApplication sharedApplication] delegate] window],[UIApplication sharedApplication].keyWindow  );
//    });
    

    
//    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(10, 10, 300, 300)];
//    view.backgroundColor = [UIColor orangeColor];
//    [[[UIApplication sharedApplication].delegate window] addSubview:view];
//    
//    UIWindow *window = [[UIWindow alloc] initWithFrame:CGRectMake(100, 200, 200, 200)];
//    [window addSubview:view];
//    [window makeKeyAndVisible];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

#import "wgj01push1.h"

@implementation wgj01push1
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(10, 350, 200, 50)];
    button.backgroundColor = [UIColor orangeColor];
    [button setTitle:@"wgj01push1Title" forState:(UIControlStateNormal)];
    [button addTarget:self action:@selector(clickBtn) forControlEvents:(UIControlEventTouchUpInside)];
    [self.view addSubview:button];
}
@end