Question

我是Cocoa的新手，我在编写一个示例应用程序时遇到了一些麻烦：

@implementation DeviceDetection    
- (id) init {
    self = [super init];
    if (self) {

        notCenter = [[NSWorkspace sharedWorkspace] notificationCenter];
        [notCenter addObserver:self
                      selector:@selector(discMounted:)
                          name:@"NSWorkspaceDidMountNotification" 
                        object:[NSWorkspace sharedWorkspace]]; // Register for all notifications
    }

    return self;
}

- (void)discMounted:(NSNotification *)notification
{
    NSLog(@"COUCOU");
}    
@end



#import <Foundation/Foundation.h>

@interface DeviceDetection : NSObject {

    NSNotificationCenter *notCenter;

}

- (void) discMounted:(NSNotification *)notification;


@end




@implementation AppDelegate
@synthesize window = _window;

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    // Insert code here to initialize your application
    DeviceDetection* d = [[DeviceDetection alloc] init];

    [d value];
} 
@end

使用那段代码，当我插入USB驱动器时，我收到以下错误：

[NSRunLoop discMounted:]: unrecognized selector sent to instance 0x10054c5a0

有什么理由？

THX

Answer 1

您需要定义dealloc -

的DeviceDetection方法

-(void)dealloc {
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

编辑1 -

DrivesOnDock[5207:707] -[DeviceDetection value]: unrecognized selector sent to instance 0x100475b40 when the app starts.

发生上述错误是因为您未在value类中定义DeviceDetection。

NotificationCenter： - [NSRunLoop]：发送到实例的无法识别的选择器

1 个答案: