Mac OS X Cocoa 多视图应用程序导航

我已经花了整整 2 天的时间试图弄清楚如何使用 NSViewControllers 来创建多视图应用程序。

这就是我所做的。

我有 2 个视图控制器和 MainMenu.xib 的窗口。 我还有一个 AppController，它是两个视图控制器的委托。

当我启动该应用程序时，首先映入眼帘的是 MainMenu.xib 的窗口视图，其中包含一个按钮。单击此按钮后，IBAction 会发送到 appController 并要求 SecondViewController 显示其笔尖。到目前为止，一切都很好，nib 文件也正确显示。

在 SecondViewController 上，有另一个按钮将另一个 IBAction 发送到 appController 并要求显示 FirstViewController 但没有任何反应， 没有崩溃，没有警告...任何帮助将不胜感激... 预先感谢您的耐心等待...

这是 AppController.h 的代码：

#import <Foundation/Foundation.h>
#import "SecondViewController.h"
#import "FirstViewController.h"

@interface AppController : NSObject

@property (strong) IBOutlet NSWindow *mainWindow;

@property (strong) IBOutlet SecondViewController *secondViewController;
@property (strong) IBOutlet FirstViewController *firstViewController;


- (IBAction)secondButtonfromsecondViewControllerClicked:(id)sender;

- (IBAction)buttonClicked:(id)sender;

@end

这是 AppController.m 的代码：

#import "AppController.h"


@implementation AppController
@synthesize mainWindow = mainwindow;
@synthesize secondViewController;
@synthesize firstViewController;

- (IBAction)buttonClicked:(id)sender {

     NSLog(@"button from second View Controller clicked");

     self.secondViewController = [[SecondViewController  
     alloc]initWithNibName:@"SecondViewController" bundle:nil];
     self.mainWindow.contentView = self.secondViewController.view;
     [self.secondViewController.view setAutoresizingMask:NSViewWidthSizable | 
     NSViewHeightSizable];
}

 - (IBAction)secondButtonfromsecondViewControllerClicked:(id)sender {

     NSLog(@"button from first ViewController clicked");

     self.firstViewController = [[FirstViewController 
     alloc]initWithNibName:@"FirstViewController" bundle:nil];
     self.mainWindow.contentView = [self.firstViewController view];

}


@end

好吧，任何人都可以帮助我，我只需要一个单一视图应用程序，它显示第一个 ViewController，第一个 viewController 上有一个按钮，将我带到第二个视图控制器，第二个按钮将我带回我的第一个视图控制器......我已经花了一个多星期的时间了……徒劳无功…… PS：我不想在 mainMenu.xib 窗口或选项卡上有任何按钮。

这就是我的问题的解决方案。

这是 AppDelegate.h 的代码：

  //  AppDelegate.h


 #import <Cocoa/Cocoa.h>
 #import "FirstViewController.h"
 #import "SecondViewController.h"

 //We need to declare the AppDelegate class as being the delegate for both 
 //FirstViewController and SecondViewController

 @interface AppDelegate : NSObject <NSApplicationDelegate, 
 FirstViewControllerDelegate, SecondViewControllerDelegate>

 @property (strong, nonatomic) NSWindow *window;
 @property (strong) FirstViewController *firstViewController;
 @property (strong) SecondViewController *secondViewController;

 -(void) goToSecondView;
 -(void) goToFirstView;

 @end

现在，这是 AppDelegate.m：

 //  AppDelegate.m

 #import "AppDelegate.h"


 @implementation AppDelegate

 @synthesize window = _window;
 @synthesize firstViewController;
 @synthesize secondViewController;

 -(void) awakeFromNib {

 [self goToFirstView];
 self.firstViewController.delegate = self;

 }


 -(void) goToSecondView {

        if (self.secondViewController ==nil) {
            self.secondViewController =[[SecondViewController alloc] 
            initWithNibName:@"SecondViewController" bundle:nil];
        }

        self.window.contentView = [self.secondViewController view];
  }

 -(void) goToFirstView {

 if (self.firstViewController ==nil) {
     self.firstViewController =[[FirstViewController alloc] 
     initWithNibName:@"FirstViewController" bundle:nil];
   }

    self.window.contentView = [self.firstViewController view];

 }

 @end

接下来我们需要在 FirstViewController 和 SecondViewController 中设置委托

//  FirstViewController.h

#import <Cocoa/Cocoa.h>
#import "SecondViewController.h"

//We declare the delegation protocole:

@protocol FirstViewControllerDelegate <NSObject>

-(void)goToSecondView;

@end

@interface FirstViewController : NSViewController

- (IBAction)firstViewControllerButtonClicked:(id)sender;

@property (nonatomic, strong) id <FirstViewControllerDelegate> delegate;

@end

这是 FirstViewController.m：

 //  FirstViewController.m

 #import "FirstViewController.h"

 @implementation FirstViewController
 @synthesize delegate;

 - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{
   self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
   if (self) {

    self.delegate = [NSApp delegate];

    }

   return self;
 }

 - (IBAction)firstViewControllerButtonClicked:(id)sender {

   NSLog(@"button from first View Controller clicked");

   if ([self.delegate respondsToSelector:@selector(goToSecondView)]) {
    [self.delegate goToSecondView];
   }
 }

 @end

现在，SecondViewController 也一样：

 //  SecondViewController.h

 #import <Cocoa/Cocoa.h>

 @protocol SecondViewControllerDelegate <NSObject>

 -(void)goToFirstView;

 @end

 @interface SecondViewController : NSViewController

 @property (nonatomic, strong) id <SecondViewControllerDelegate> delegate;

 - (IBAction)goToFirstViewControllerButtonClicked:(id)sender;

 @end

这是 SecondViewController.m：

  //  SecondViewController.m

  #import "SecondViewController.h"

  @interface SecondViewController ()

  @end

  @implementation SecondViewController

  - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil{
  self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
  if (self) {

      self.delegate = [NSApp delegate];
   }

    return self;
  }

  - (IBAction)goToFirstViewControllerButtonClicked:(id)sender {

    NSLog(@"button from Second View Controller clicked");

    if ([self.delegate respondsToSelector:@selector(goToFirstView)]) {
    [self.delegate goToFirstView];
  }

 }
 @end

好吧，我想这段代码可能会得到改进，如果您有任何建议，请随时告诉我。希望它能帮助其他人。