objective-c - 如何创建 GUI 并以编程方式对 Cocoa 事件使用react？

Question

我找到了如何以编程方式在 Cocoa 中创建窗口，但不知道如何对事件使用react。窗口没有对退出请求或按钮单击使用react。

我尝试添加以下 Controller 并使用 setDelegate/setTarget 但没有成功:

    @interface AppController : NSObject {
    }
    - (IBAction)doSomething:(id)sender;
    @end

    @implementation AppController
    - (IBAction)doSomething:(id)sender;
    {
        printf("Button clicked!\n");
    }
    @end

    int main(int argc, char **args){
        NSRect frame = NSMakeRect(0, 0, 200, 200);

        AppController *controller = [[AppController alloc] init];

>       [[NSApplication sharedApplication] setDelegate:controller];
        NSWindow* window  = [[NSWindow alloc] initWithContentRect:frame
                                            styleMask:NSBorderlessWindowMask|NSClosableWindowMask|NSMiniaturizableWindowMask|NSResizableWindowMask
                                            backing:NSBackingStoreBuffered
                                            defer:NO];
        [window setBackgroundColor:[NSColor blueColor]];

        NSButton *button = [ [ NSButton alloc ] initWithFrame: NSMakeRect( 30.0, 20.0, 80.0, 50.0 ) ];
        [ button setBezelStyle:NSRoundedBezelStyle];
        [ button setTitle: @"Click" ];
>       [ button setAction:@selector(doSomething:)];
>       [ button setTarget:controller];
        [ [ window contentView ] addSubview: button ];

        [window makeKeyAndOrderFront:NSApp];

        [[NSRunLoop currentRunLoop] run];
        return 0;
    }

Answer 1

您需要调用 -[NSApplication run] 而不是 -[[NSRunLoop currentRunLoop] run]。如果你看一下方法的基本结构，原因应该很清楚:

- (void)run
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];

    [self finishLaunching];

    shouldKeepRunning = YES;
    do
    {
        [pool release];
        pool = [[NSAutoreleasePool alloc] init];

        NSEvent *event =
            [self
                nextEventMatchingMask:NSAnyEventMask
                untilDate:[NSDate distantFuture]
                inMode:NSDefaultRunLoopMode
                dequeue:YES];

        [self sendEvent:event];
        [self updateWindows];
    } while (shouldKeepRunning);

    [pool release];
}

NSApplication 封装了很多关于如何获取事件、如何调度它们以及如何更新窗口的内容。