UIView及其子类

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    // Override point for customization after application launch.    //创建window    self.window = [[UIWindow alloc ]init];    //让window和屏幕的宽高一样，位置也一样    _window.frame =[ UIScreen mainScreen].bounds;//bounds =(0,0,屏幕宽，屏幕高）    _window.backgroundColor = [UIColor yellowColor];    //上面两步相当于    //self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];    //显示屏幕    [_window makeKeyAndVisible];    //创建BlueView试图    //开辟空间并初始化    UIView * blueView = [[UIView alloc]initWithFrame:CGRectMake(100, 100, 100, 100)];    //对视图进行设置    blueView.backgroundColor = [UIColor blueColor];    //将视图添加到window来显示    [_window addSubview:blueView];    //释放视图对象    UIView * redView = [[UIView alloc]initWithFrame:CGRectMake(100, 300, 100, 100)];    //对视图进行设置    redView.backgroundColor = [UIColor redColor];    //将试图添加到window来显示    [_window addSubview:redView];    //释放视图对象    UIView * blackView = [[UIView alloc]initWithFrame:CGRectMake(100, 200, 100, 100)];    blackView.backgroundColor = [ UIColor blackColor];    [_window addSubview:blackView];    //参照blueview（父视图）左上角的起点位置，    UIView * orangeView =[[UIView alloc]initWithFrame:CGRectMake(50, 50, 100, 100)];    orangeView.backgroundColor = [UIColor orangeColor];    [blueView addSubview:orangeView];    //修改中心点位置    //blackView.center = CGPointMake(200, 300);    CGPoint  tempCenter = blackView.center;    tempCenter.x = 200;    tempCenter.y = 350;    blackView.center = tempCenter;    [_window release];    [blueView release];    [redView release];    [blackView release ];    [orangeView release];#pragma mark----frame,center,bounds    //frame:可以改变视图的大小和位置，相对于父视图    //center:只能改变视图的位置    //bounds：能改变视图的大小，但是中心点不会改变，相对于自身。但是它会影响这个视图上所有子视图的布局（位置）。#pragma mark-----添加视图    UIView * grayView =[[UIView alloc]initWithFrame:CGRectMake(50, 50, 100, 100)];    grayView.backgroundColor =[UIColor grayColor];    [_window insertSubview:grayView atIndex:0];    [grayView release];    //将grayview移到最前面（最上面）    [_window bringSubviewToFront:grayView];    //将redView从父视图上移除    //[redView removeFromSuperview];    //UIView的相关属性    //redView.hidden  = YES;//设置视图是否隐藏    redView.alpha = 0.5;//设置透明度，默认1.0   ；    NSLog(@"%@",redView .superview);//获取父视图    NSLog(@"%@",redView.subviews);//获取某视图上的所有子视图    grayView.tag = 100;    UIView * v =[_window viewWithTag:100];    NSLog(@"%@",v);#pragma mark----UILable    UILabel * label = [[UILabel alloc] initWithFrame:CGRectMake(100, 400, 200, 60)];    //设置文本内容（显示的内容）    label.text = @"Hello Baby! Can I make L with you!";    //背景颜色    label.backgroundColor = [UIColor cyanColor];    //文本字体    label.font = [UIFont fontWithName:@"Times New Roman" size:14];    NSLog(@"%@",[UIFont familyNames]);    //文本颜色    label.textColor =   [UIColor redColor];    //设置对齐方式    label.textAlignment= 0 ;    //设置换行模式    label.lineBreakMode= NSLineBreakByWordWrapping ;    //设置行数    label.numberOfLines = 3;    //设置文本阴影    label.shadowColor =[ UIColor blackColor];   //设置阴影的偏移量    label.shadowOffset = CGSizeMake(20,20);    [_window addSubview:label];    [label release];