UIWindow ,UIlable

 1  //1.创建window,UIScreen是屏幕类,创建和屏幕等大的窗口
 2     self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
 3     //2.背景颜色
 4     //self.window.backgroundColor = [UIColor greenColor]; 
 9     
10     self.window.backgroundColor = [UIColor whiteColor];
11     //3.将window设为主window,并使之可见
12     [self.window makeKeyAndVisible];
13     //4.设置根试图控制器
14     self.window.rootViewController = [ViewController new];
15 //    /*
16 //     屏幕尺寸(point)
17 //     iPhone 3G/3GS/4/4S  320*480
18 //     iPhone 5C/5S  320*568
19 //     iPhone 6/6S   375*667
20 //     iPhone 6P/6SP 414 *736
21 //     */
22 //   
23 //    NSLog(@"当前屏幕尺寸= %@", NSStringFromCGRect([UIScreen mainScreen].bounds));

1 CGFloat redColor = arc4random()%256/255.0;
2 CGFloat greenColor = arc4random()%256/255.0;
3 CGFloat blueColor = arc4random()%256/255.0;
4  UIView *aView = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
5   aView.backgroundColor = [UIColor colorWithRed:redColor green:greenColor blue:blueColor alpha:1];
6   [self.window addSubview:aView];

1 //    exchangeSubviewAtIndex: withSubviewAtIndex: 交换子视图层级
2     //    insertSubview:atIndex:在指定的index处插入子视图
3     //    insertSubview:aboveSubview:在指定的视图上面添加子视图
4     //    insertSubview:belowSubview:在指定的视图下面添加子视图
5     //    bringSubviewToFront:把指定的子视图移动到最前面
6     //    sendSubviewToBack:把指定的子视图移动到最后面
7     //    exchangeSubviewAtIndex:withSubviewAtIndex:  交换两个指定索引位置的子视图
8     //    removeFromSuperview把视图从父视图上移除
9  //bounds是自身视图左上角相对于自身坐标系的位置,更改bounds对本身没有影响,但是会改变子视图的位置

 1 UIView *view1 = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
 2     view1.backgroundColor = [UIColor cyanColor];
 3     //设置显隐性(默认为NO)
 4     view1.hidden = NO;    //设置透明度
 5 
 6     view1.alpha = 1;
 7     //获取到父视图
 8     NSLog(@"%@",view1.superview);
 9     
10     [self.window addSubview:view1];
11     //获取到子视图
12     NSArray *arr = self.window.subviews;
13     NSLog(@"%@",arr);

//1.创建并初始化
    UILabel *lable = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 200, 200)];
    lable.text = @"不知不觉中来到北京也有一个多月了,在这段时间里我只进行一件事,那就是学习,虽然单调但是也充满了欢乐,幽默的老师,可爱的同学,还有那呆萌的同桌.说的我的同桌,不得不说这个姑娘很喜欢美食,遇到美食两眼放光";
    lable.backgroundColor = [UIColor yellowColor];
    //设置行数,0代表多行,自适应
    lable.numberOfLines = 0;
    //修改字体颜色
    lable.textColor = [UIColor redColor];
    //修改字体大小
    lable.font = [UIFont systemFontOfSize:24];
    //设置对齐方式
    lable.textAlignment = NSTextAlignmentCenter;
    //设置阴影
    lable.shadowOffset = CGSizeMake(2, 2);
    lable.shadowColor = [UIColor blackColor];
    //设置边框
    lable.layer.borderWidth = 3;
    lable.layer.borderColor = [UIColor blueColor].CGColor;
    //设置圆角,内切圆的半径
    lable.layer.cornerRadius = 5;
    //允许切除
    lable.layer.masksToBounds = YES;
    //下面这一句和上面的一句实现的效果完全一样
    //labe.clipsToBounds = YES;
    [self.window addSubview:lable];