self.headerView = [[WZDraggableSwitchHeaderView alloc] initWithDelegate:self
                                                                      frame:CGRectMake(0,0,self.view.bounds.size.width,50)
                                                          normalStateHeight:20.0f
                                                     heightCanTriggerSwitch:70.0f];
[self.view addSubView:self.headerView];           

#pragma mark - WZDraggableSwitchHeaderViewDelegate

- (void)WZDraggableSwitchHeaderViewDidTriggerDeepDragging;
{
    [self.navigationController.view.layer addAnimation:[WZAnimatingTransition backwardTransition] forKey:@"transition"];
    [self.navigationController popToRootViewControllerAnimated:NO];
}

#pragma mark - UIScrollViewDelegate

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    [self.headerView WZDraggableSwitchHeaderViewDidScroll:scrollView];
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    [self.headerView WZDraggableSwitchHeaderViewDidEndDragging:scrollView];
}

/// The y contentOffset range between normal state and shallow dragging state. If end dragging on this range, `- WZDraggableSwitchHeaderViewDidTriggerShallowDragging` will be invoked.
/// Default is 20.0f.
@property (nonatomic, assign) CGFloat normalStateHeight;

/// The total height of this header view will trace down with. End up dragging on the y contentOffset if less than `heightCanTriggerSwitch`, `- WZDraggableSwitchHeaderViewDidTriggerDeepDragging` will be invoked properly.
/// Default is 70.0f.
@property (nonatomic, assign) CGFloat heightCanTriggerSwitch;

/// The status label shows the text of state.
@property (nonatomic, strong) UILabel *statusLabel;

/// The button can be tapped to return to menu.
@property (nonatomic, strong) UIButton *backButton;

/// The layer of arrow Image.
@property (nonatomic, strong) CALayer *arrowImage;

/// The state of this headerView.
@property (nonatomic, assign) WZDraggableSwitchState state;

/// The text will show in normal state. Default is `ABOUT`.
@property (nonatomic, strong) NSString *normalStateText;

/// The text will show on shallow dragging state. Default is `PULL TO RETURN TO MENU.`
@property (nonatomic, strong) NSString *shallowStateText;

/// The text will show on deep dragging state. Default is `RELEASE TO RETURN TO MENU.`
@property (nonatomic, strong) NSString *deepStateText;