//创建UILabel函数
- (void) creatUILabel{
    //定义并创建一个UILabel对象
    UILabel* label = [[UILabel alloc] init];
    
    //文字赋值,字符串对象，设定字体大小，颜色，阴影，阴影偏移量，对齐方式，显示行数(默认1，设为0时智能按合适的行数显示)
    label.text = @"你好啊，how are you 你好啊，how are you 你好啊，how are you";
    label.font = [UIFont systemFontOfSize:12];
    label.textColor = [UIColor blueColor];
    label.shadowColor = [UIColor grayColor];
    label.shadowOffset = CGSizeMake(2, 1);
    label.textAlignment = NSTextAlignmentCenter;
    label.numberOfLines = 0;
    
    //设定label的显示位置(左坐标，上坐标，宽，高)
    label.frame = CGRectMake(100, 400, 160, 40);
    
    //设定label的背景颜色,clearColor透明色
    label.backgroundColor = [UIColor grayColor];
    
    //将label显示到屏幕上
    //当前.视图 增加子视图：label
    [self.view addSubview:label];

}

//创建普通按钮函数
- (void) createUIRectButton{
    //创建圆角按钮
    UIButton* btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    btn.frame = CGRectMake(100, 100, 100, 60);
    
    //设置按钮文字内容，正常状态和按下状态,设置文字颜色
    [btn setTitle:@"按钮1" forState:UIControlStateNormal];
    [btn setTitle:@"按钮被按下" forState:UIControlStateHighlighted];
    [btn setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
    [btn setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];
    
    //设置背景颜色
    btn.backgroundColor = [UIColor grayColor];
    
    //添加事件
    [btn addTarget:self action:@selector(pressBtn:) forControlEvents:UIControlEventTouchUpInside];
    
    //添加到视图中显示
    [self.view addSubview:btn];
}

//创建显示图片按钮函数
- (void) createImageBtn{
    //创建一个自定义类型的btn
    UIButton* btnImage = [UIButton buttonWithType:UIButtonTypeSystem];
    btnImage.frame = CGRectMake(100, 200, 100, 100);
    
    //显示图片
    UIImage* icon01 = [UIImage imageNamed:@"2.png"];
    [btnImage setImage:icon01 forState:UIControlStateNormal];
    
    //添加事件
    [btnImage addTarget:self action:@selector(pressBtn:) forControlEvents:UIControlEventTouchUpInside];
    
    [self.view addSubview:btnImage];
    
    //添加按钮唯一标记
    btnImage.tag = 101;
    
}

//响应按钮按下事件函数
- (void) pressBtn:(UIButton*) btn{
    if(btn.tag == 101){
        NSLog(@"hahaha...");
    }else{
        NSLog(@"hehehe...");
        btn.backgroundColor = [UIColor redColor];
    }

}

//程序入口
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    //调用创建UI函数
    [self creatUILabel];
    [self createUIRectButton];
    [self createImageBtn];
}



//按钮显示网络图片
int all_number = (int)[responseObject[@"data"] count];
for (NSInteger i = 0; i < all_number; i++) {
    NSURL * imageUrl = [NSURL URLWithString: responseObject[@"data"][i][@"avatar"]];
    UIImage * image = [UIImage imageWithData: [NSData dataWithContentsOfURL: imageUrl]];

    //设置图片图片为主，不拉伸
    //[self.four_site[i] setImage:image forState:normal];

    //设置按钮背景图片，按钮为主，图片上的字依然会显示，按钮变大图片会拉伸
    [self.four_site[i] setBackgroundImage: image forState: normal];
}