Question

我让委托工作，因为数据正从模态传递到呈现视图控制器。但是呈现视图控制器没有显示它从模态接收的数据。我查看了其他帖子，他们说要使用委托/协议方法，但不解释如何/为什么呈现VC刷新。我假设我的委托设置不正确。否则，刷新数据的方法是什么？我已经检查过了，并且没有调用viewWillAppear和viewDidAppear。

SCCustomerDetailVC.h（呈现VC）

#import "SCCustomersVC.h"

@interface SCCustomerDetailVC : UIViewController <SCCustomersVCDelegate>

@property (atomic, strong) SCCustomer *customer;
@property (strong, nonatomic) IBOutlet UIButton *changeCustomerButton;

- (IBAction)changeCustomerButtonPress:(UIButton *)sender;

@end

SCCustomerDetailVC.m（呈现VC）

- (IBAction)changeCustomerButtonPress:(UIButton *)sender 
{    
    UINavigationController *customersNC = [self.storyboard instantiateViewControllerWithIdentifier:@"customersNC"];
    SCCustomersVC *customersVC = (SCCustomersVC *)customersNC.topViewController;
    customersVC.delegate = self;
    [self presentViewController:customersNC animated:YES completion:nil];
}

//Protocol methods
- (void)passCustomer:(SCCustomer *)customer
{
    self.customer = customer;

    //At this point, self.customer has the correct reference

    [self dismissViewControllerAnimated:YES completion:nil];
}

SCCustomersVC.h（Modal VC）

#import "SCCustomersVCDelegate.h"

@class SCCustomerDetailVC;

@interface SCCustomersVC : UIViewController <UITableViewDelegate, UITableViewDataSource, UISearchBarDelegate>

@property (weak, nonatomic) id <SCCustomersVCDelegate> delegate;

@end

SCCustomersVC.m（Modal VC）

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    SCCustomer *customer = [self customerAtIndexPath:indexPath];
    [self.delegate passCustomer:customer];
}

SCCustomersVCDelegate.h

@class SCCustomer;

@protocol SCCustomersVCDelegate <NSObject>
@optional

- (void)passCustomer:(SCCustomer *)customer;

@end

Answer 1

我觉得你快到了。编辑 - 刚刚了解here，在iOS＆gt; 5中，viewWillAppear行为有所不同。您仍然希望视图将以模型状态更新您的视图，因为它需要在初始演示时执行此操作。

可以从模态vc或委托方法中调用它。因此，请向viewWillAppear添加代码，以使用视图控制器的模型状态更新视图...

// SCCustomerDetailVC.m
- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];

    // making up an IBOutlet called someLabel
    // making up a model method (description) that returns a string representing your model
    self.someLabel.text = [self.customer description];
}

然后，从显示的vc或委托中，调用viewViewWillAppear：

- (void)passCustomer:(SCCustomer *)customer
{
    self.customer = customer;
    [self viewWillAppear:YES];
    [self dismissViewControllerAnimated:YES completion:^{}];
}

Answer 2

您应该在设置“customer”

后重新加载UI

- (void)passCustomer:(SCCustomer *)customer
{
    self.customer = customer;

    //At this point, self.customer has the correct reference

    [self dismissViewControllerAnimated:YES completion:^{
            // reload your UI here or call a method which will reload your ui
            // e.g. for tableView it will be [tableView reload];
        }];
}

在通过委托解除其呈现的模态视图控制器后，刷新UIViewController中的数据

2 个答案: