左右侧滑原理与实现方式

左右侧滑的原理在于把左边的vc.view,右边的vc.view和主视图控制器的view加到同一个vc。view上去，为主视图控制器的view加上拖拽和单点手势，做相应的处理控制相应的试图的frame就可以了。好了，下面我们来自己试试。第一步：为容器视图控制器声明一个方法：
-(instancetype)initWithLeftCtrl:(UIViewController *)leftCtrl withMainCtrl:(UIViewController *)maiCtrl withRightCtrl:(UIViewController *)rightCtrl;
在。m文件中实现这个方法实现方式如下：

-(instancetype)initWithLeftCtrl:(UIViewController *)leftCtrl withMainCtrl:(UIViewController *)maiCtrl withRightCtrl:(UIViewController *)rightCtrl
{
    self=[super initWithNibName:nil bundle:nil];
    if(self){
        _leftCtrl=leftCtrl;
        _mainCtrl=maiCtrl;
        _rightCtrl=rightCtrl;
        
        _isMain=YES;
        
        _panRecognizer=[[UIPanGestureRecognizer alloc]initWithTarget:self action:@selector(handpan:)];
        _panRecognizer.maximumNumberOfTouches=1;
        
        _tapRecognizer=[[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(handTap:)];
        
        [_mainCtrl.view addGestureRecognizer:_tapRecognizer];
        [_mainCtrl.view addGestureRecognizer:_panRecognizer];

        
        _leftCtrl.view.frame=CGRectMake(-WIDTH, 0, WIDTH, HEIGHT);
        _rightCtrl.view.frame=CGRectMake(self.view.bounds.size.width+WIDTH,
0, WIDTH, HEIGHT);
        [self.view addSubview:_leftCtrl.view];
        [self.view addSubview:_mainCtrl.view];
        [self.view addSubview:_rightCtrl.view];
    }
    return self;
}
第三步：实现拖拽手势和单点手势的方法：

-(void)handpan:(UIPanGestureRecognizer *)pan
{
    CGPoint
point=[pan
translationInView:_mainCtrl.view];
    if(_isMain){
//point.x>0表示右滑，显示左视图
        if(point.x>0){
            [self showLeftCtrl];
        }else{
            [self showRightCtrl];
        }
    }
}

-(void)handTap:(UITapGestureRecognizer *)tap
{
    //单点主视图的view显示主视图
    [self
showMainCtrl];
}
showMainCtrl与showLeftCtrl与showRightCtrl方法实现如下：

-(void)showMainCtrl
{
    _isMain=YES;
    [UIView animateWithDuration:0.35
animations:^{
        _leftCtrl.view.frame=CGRectMake(-WIDTH,
0,WIDTH, HEIGHT);
        _mainCtrl.view.frame=CGRectMake(0,
0, self.view.bounds.size.width,
HEIGHT);
        _rightCtrl.view.frame=CGRectMake(self.view.bounds.size.width+WIDTH,
0, WIDTH,
HEIGHT);
    }];
}

-(void)showLeftCtrl
{
    _isMain=NO;
    [UIView animateWithDuration:0.35
animations:^{
        _leftCtrl.view.frame=CGRectMake(0,
0,WIDTH, HEIGHT);
        _mainCtrl.view.frame=CGRectMake(WIDTH,
0, self.view.bounds.size.width,
HEIGHT);
        _rightCtrl.view.frame=CGRectMake(self.view.bounds.size.width+WIDTH+WIDTH,
0, WIDTH,
HEIGHT);
    }];
}

-(void)showRightCtrl
{
    _isMain=NO;
    [UIView animateWithDuration:0.35
animations:^{
        _rightCtrl.view.frame=CGRectMake(self.view.bounds.size.width-WIDTH,
0, WIDTH,
HEIGHT);
        _leftCtrl.view.frame=CGRectMake(-WIDTH-WIDTH,
0,WIDTH, HEIGHT);
        _mainCtrl.view.frame=CGRectMake(-WIDTH,
0, self.view.bounds.size.width,
HEIGHT);
        
    }];
}
这里的_isMain表示是否显示的不是主视图，便于过滤不需要的效果