UIView点击事件。弹出视图，背景虚化。

@interface CountryViewController

//背景

@property (strong, nonatomic) UIView *BackView;

end

//设置背景虚化

-(UIView *)BackView{

    if (!_BackView) {

        _BackView = [[UIView alloc]initWithFrame:self.view.bounds];

        //背景虚化

        UIColor *myColor = [UIColor colorWithWhite:0.5 alpha:0.5];

        _BackView.backgroundColor = myColor;

        [self.view addSubview:self.BackView];

//设置在当前控制器前面

        [self.view bringSubviewToFront:self.BackView];

//一开始隐藏

        self.BackView.hidden = YES;

        

        //添加点击事件

        UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(actiondo)];

        [_BackView addGestureRecognizer:tapGesture];

    }

    return _BackView;

}

//实现方法

-(void)actiondo{

    NSLog(@"1231231231231231231231231231231");

}

 //设置一个按钮事件

-(void)click{

　　//显示UIview

　　self.BackView.hidden = NO;

}