开发中问题解决

1.popToViewController的用法

 [self.navigationController popToViewController:[self.navigationController.viewControllers objectAtIndex:1]animated:YES];

 for (UIViewController *temp in self.navigationController.viewControllers) {
                                 if ([temp isKindOfClass:[SubmitOrderController class]]) {
                                     [self.navigationController popToViewController:temp animated:YES];
                                 }
                             }

2.想改变视图的透明度，但不改变视图上控件的透明度

<span style="color:#333333;">self.view.backgroundColor =[UIColor colorWithWhite:0.0f alpha:0.5];</span>

后面的参数表示灰度，从0-1之间表示从黑到白的变化，alpha就是你想调整的透明度