從菜單項（OS X）重新加載WebView

Question

我想在每次單擊某個菜單項時重新加載WebView 。 這是我的代碼不起作用。 （假定.h文件中的普通聲明。）

---

// AppDelegate.m

#import "AppDelegate.h"
// #import "ViewController.h" (in AppDelegate.h)

@interface AppDelegate ()
@end

@implementation AppDelegate

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {
  // Insert code here to initialize your application
}
- (void)applicationWillTerminate:(NSNotification *)aNotification {
  // Insert code here to tear down your application
}

// Menu Item triggers this:
- (IBAction)reloadWebView:(id)sender {
  NSLog(@"AppDelegate reloadWebView");
  ViewController * vc = [[ViewController alloc] init];
  [vc reloadWebView:sender]; // tried this,
  [vc.webview reload:sender]; // and this,
  [[vc.webview mainFrame] reload]; // and this,
  [[vc.webview mainFrame] loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://example.com/"]]]; // and this.
}

@end

---

// ViewController.m

#import "ViewController.h"

// @property (assign) IBOutlet WebView *webview; (in ViewController.h)

@implementation ViewController

@synthesize webview;

- (void)viewDidLoad {
  [super viewDidLoad];
  [[webview mainFrame] loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://example.com/"]]]; // this works
}

- (void)setRepresentedObject:(id)representedObject {
  [super setRepresentedObject:representedObject];
  // Update the view, if already loaded.
}

// Called in AppDelegate:
- (void)reloadWebView:(id)sender {
  NSLog(@"ViewController reloadWebView");
  // The problem here seems to be: webview == nil
  [webview reload:sender]; // also tried this,
  [[webview mainFrame] reload]; // and this,
  [[webview mainFrame] loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://example.com/"]]]; // and this.
}

@end

---

這就是我的全部代碼。 我剛剛開始從事這個項目。

我試過使用ViewController的按鈕。 那行得通，但我需要將此作為菜單項。

提前致謝！

Answer 1

而不是創建新的視圖控制器：

    ViewController * vc = [[ViewController alloc] init];

嘗試：

    ViewController * vc = (ViewController *)[[[NSApplication sharedApplication] mainWindow] contentViewController];

調用當前的視圖控制器