ios - 在 ipad 中关闭 ModalView 后调用 MasterView 中的函数

Question

我正在使用 iPad 的主从模板。我有一个 ViewController，我想以模态方式显示它，所以我使用了这段代码

AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];       
        m_ViewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
        m_ViewController.modalPresentationStyle = UIModalPresentationFormSheet;

        [appDelegate.splitViewController presentModalViewController:m_ViewController animated:YES];

这工作正常，ViewController 已模态加载，现在我试图关闭这个 ViewController，所以在 ViewController.m 中，我调用了这行代码

[self dismissModalViewControllerAnimated:YES];

这段代码也可以正常工作，并且 ViewController 被解雇，但是在解雇后我想在我的 MasterView 中调用一个函数。如何做到这一点？

根据与 Moxy 的讨论添加的代码。

AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
        [appDelegate.testViewController testfunction:testImage];

Answer 1

正如 amit3117 指出的那样，您应该使用委托(delegate)。该协议(protocol)至少应该使用一种方法来定义，该方法可以向委托(delegate)传达以模态方式呈现的 View Controller 已完成其工作的信息。

@class ViewController;

@protocol MyViewControllerDelegate <NSObject>

-(void)viewControllerDidFinish:(ViewController *)sender;

@end

编辑:我忘记添加您应该为 ViewController 的委托(delegate)提供一个公共(public)属性

@interface ViewController : UIViewController

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

@end

您可以使用主视图 Controller 作为委托(delegate)。因此，在您的主视图 Controller 实现中，您还会有:

@interface MyMasterViewController () <MyViewControllerDelegate>
@end

@implementation MyMasterViewController

-(void)showViewController
{
    m_ViewController = [[ViewController alloc] initWithNibName:@"ViewController" 
                                                        bundle:nil];
    m_ViewController.modalPresentationStyle = UIModalPresentationFormSheet;
    m_ViewController.delegate = self;
    // –presentModalViewController:animated: is deprecated!
    [self.parentViewController presentViewController:m_ViewController
                                            animated:YES
                                          completion:nil];
}

-(void)viewControllerDidFinish:(ViewController *)sender
{
    // Add any code you want to execute before dismissing the modal view controller
    // –dismissModalViewController:animated: is deprecated!
    [self.parentViewController dismissViewControllerAnimated:YES
                                                  completion:^{
                                                     // code you want to execute after dismissing the modal view controller
                                                  }];
}
@end

当m_ViewController完成其工作时，它应该调用:

[self.delegate viewControllerDidFinish:self];