視圖的層次結構

視圖的層次結構

AppDelegate.m

#import "AppDelegate.h"
#import "TestView.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    
    //設置未讀信息數
//    application.applicationIconBadgeNumber = 9;
    
    /*______________________________frame、bounds和center_____________________________________*/
    //坐標系的零點是在狀態欄上面
    //創建視圖
    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(50, 20, 90, 90)];
    //設置視圖的顏色
    view.backgroundColor = [UIColor redColor];
    
    //以其父視圖的起點為原點
    view.frame = CGRectMake(0, 20, 320, 40);    //center: 160  40
    
    //錯誤，  bounds的x和y必須為零，它可以改變設置大小，不可以改變位置
//    view.bounds = CGRectMake(10, 20, 90, 90);
    
    //center是用來表示視圖的中心位置的，可以改變視圖的位置，不可以改變視圖的大小
//    view.center = CGPointMake(160, 120);
    
    CGRect bounds = view.bounds;
    //NSStringFromCGRect將結構體類型的CGRect轉換成字符串
    NSString *str = NSStringFromCGRect(bounds);
    NSLog(@"str:%@",str);
    
    //添加到window上顯示
    [self.window addSubview:view];
    [view release];

    /*__________________________視圖的層次結構___________________________*/
    
    //創建父視圖
    UIView *superView = [[UIView alloc] initWithFrame:CGRectMake(0, 80, 320, 300)];
    superView.backgroundColor = [UIColor blackColor];
    //添加到window上面顯示
    [self.window addSubview:superView];//retain
    [superView release];
    
    //給superView添加子視圖
    UIView *view1 = [[UIView alloc] initWithFrame:CGRectMake(10, 20, 300, 200)];
    view1.backgroundColor = [UIColor greenColor];
    //添加到supView上面顯示
    [superView addSubview:view1];
    [view1 release];
    
    UIView *view2 = [[UIView alloc] initWithFrame:CGRectMake(20, 40, 300, 160)];
    view2.backgroundColor = [UIColor orangeColor];
    //添加到supView上顯示
//    [superView addSubview:view2];
    
    //將視圖插入到superView子視圖的下面，索引為0
    [superView insertSubview:view2 atIndex:0];
    
    //將view2作為supView的子視圖插入到view1的上面
    [superView insertSubview:view2 aboveSubview:view1];
    
    //將view2作為supView的子視圖插入到view1的下面
    [superView insertSubview:view2 belowSubview:view1];
    
    [view2 release];
    
    //將view2作為supView的子視圖移動到最上面
    [superView bringSubviewToFront:view2];
    
    //將view2作為supView的子視圖移動到最下面
    [superView sendSubviewToBack:view2];
    
    //交換superView兩個子視圖的位置
    [superView exchangeSubviewAtIndex:0 withSubviewAtIndex:1];
    
    //取得當前視圖的父視圖view1.superview;
    NSLog(@"%@",view1.superview);
    
    //如果想判斷一個視圖是否在顯示，可以判斷view.superview是否存在
    
    //將view1從父視圖上移除
    if (view1.superview != nil) {
        [view1 removeFromSuperview];
    }
    //注意：
//    removeFromSuperview只是將視圖從父視圖上面移除，但是不是銷毀，還是在內存中存在的
    NSLog(@"view1:%@",view1);
    
    
    /*__________________________UIView的常用屬性___________________________*/
    
    //1.透明度,范圍是 [0，1]
    //注意：如果你設置父視圖的透明度，子視圖的這個屬性也會跟著變化
//    superView.alpha = .5;
//    view2.alpha = .5;
    
    //2.背景顏色
//    clearColor是透明的
    superView.backgroundColor = [UIColor greenColor];
    //用過三色值設置顏色
//    superView.backgroundColor = [UIColor colorWithRed:<#(CGFloat)#> green:<#(CGFloat)#> blue:<#(CGFloat)#> alpha:<#(CGFloat)#>]
    
    //3.subviews得到視圖的所有子視圖
    NSArray *views = superView.subviews;
    for (UIView *view in views) {
        view.backgroundColor = [UIColor darkGrayColor];
    }
    
    //4.hidden 隱藏
//    view2.hidden = YES;
    
    //5.superview得到當前視圖的父視圖
    NSLog(@"supView:%@",superView);
    NSLog(@"test:%@",view2.superview);
    
    //6.tag：視圖的標簽值
    //如果想通過tag得到視圖，tag設置大於等於100
    
    /*
     注意點：1：在同一個父視圖上面，兩個子視圖不能設置相同的tag
            2:可以用父視圖的父視圖找子視圖，理解查找機制
     */
    superView.tag = 100;
    
    view2.tag = 101;
    
    //7.開啟多點觸摸
    superView.multipleTouchEnabled = YES;
    
    //8.開啟響應觸摸事件
    superView.userInteractionEnabled = NO;
    
    UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    button.backgroundColor = [UIColor redColor];
    button.frame = CGRectMake(90, 90, 90, 90);
    [button addTarget:self action:@selector(buttonAction) forControlEvents:UIControlEventTouchUpInside];
    [superView addSubview:button];
    
    UIView *view3 = [[UIView alloc] initWithFrame:CGRectMake(0, 290, 40, 40)];
    view3.backgroundColor = [UIColor blueColor];
    [superView addSubview:view3];
    /*
     clipsToBounds設置為yes後，會將超過父視圖的子視圖部分截取
     */
    superView.clipsToBounds = YES;
    
    [view3 release];
    
    /*__________________________UIView的內存管理___________________________*/
    TestView *testView = [[TestView alloc] initWithFrame:CGRectMake(0, 400, 320, 60)];
    testView.backgroundColor = [UIColor cyanColor];
    NSLog(@"testView:%d",testView.retainCount);
    
    [self.window addSubview:testView];
    NSLog(@"testView:%d",testView.retainCount);
    
    [testView release];  //1
    NSLog(@"testView:%d",testView.retainCount);
    
    //從父視圖上移除，被釋放
    [testView removeFromSuperview];
    
    return YES;
}

- (void)buttonAction
{
    NSLog(@"buttonAction");
}
//程序進入後台
- (void)applicationDidEnterBackground:(UIApplication *)application
{
    
    //通過tag值取得視圖
//    UIView *view = [self.window viewWithTag:100];
//    view.backgroundColor = [UIColor redColor];
    
    UIView *view = [self.window viewWithTag:101];
    view.backgroundColor = [UIColor orangeColor];
    
}



@end