//点击空白处事件

    UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(keyboardHide:)];

    //设置成NO表示当前控件响应后会传播到其他控件上，默认为YES。

    tapGestureRecognizer.cancelsTouchesInView = NO;

    //将触摸事件添加到当前view

    [self.view addGestureRecognizer:tapGestureRecognizer];

 

//点击空白处隐藏键盘

-(void)keyboardHide:(UITapGestureRecognizer*)tap{

    [谁发起的键盘写谁 resignFirstResponder];

}

 

a到b b到c c返回直接到a 页面

 // 获取所有的控制器数组

    NSMutableArray *vcArr = [NSMutableArray arrayWithArray:self.navigationController.viewControllers];

    // 将上级页面从数组中移除

    [vcArr removeObjectAtIndex:vcArr.count-2];

    self.navigationController.viewControllers = vcArr;

    

    [self.navigationController popViewControllerAnimated:YES];

     [SVProgressHUD dismiss];