禁止边缘手势

- (void)viewDidAppear:(BOOL)animated{
    [super viewDidAppear:YES];
    // 禁用iOS7返回手势
    self.navigationController.interactivePopGestureRecognizer.enabled = NO;
    
}
-(void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:YES];
    // 开启
    self.navigationController.interactivePopGestureRecognizer.enabled = YES;
}