可可中分布式对象的双向通信

Question

我对Cocoa编程很陌生.我正在学习带有分布式对象的IPC。我做了一个简单的例子，我从服务器上销售对象并在客户端调用它们，我成功地将消息从客户端对象传递到服务器，但是我想将消息从服务器传递到clientBidirectional...How，我做到了吗？

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification {

MYMessageServer   *server = [[MYMessageServer alloc] init];
NSConnection      *defaultConnection=[NSConnection defaultConnection];


[defaultConnection setRootObject:server];
   if ([defaultConnection registerName:@"server"] == NO)
{
    NSLog(@"Error registering server");
}
else
    NSLog(@"Connected");
[[NSRunLoop currentRunLoop] configureAsServer];
}

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

//Getting an Vended Object
server = [NSConnection rootProxyForConnectionWithRegisteredName:@"server" host:nil];


if(nil == server)
{
    NSLog(@"Error: Failed to connect to server.");
}
else
{

    //setProtocolForProxy is a method of NSDistantObject
    [server setProtocolForProxy:@protocol(MYMessageServerProtocol)];
    [server addMessageClient:self];
    [server broadcastMessageString:[NSString stringWithFormat:@"Connected: %@ %d\n",
                                    [[NSProcessInfo processInfo] processName],
                                    [[NSProcessInfo processInfo] processIdentifier]]];
}

}

- (void)appendMessageString:(NSString *)aString

{

NSRange    appendRange = NSMakeRange([[_messageView string] length], 0);

// Append text and scroll if neccessary
[_messageView replaceCharactersInRange:appendRange withString:aString];
[_messageView scrollRangeToVisible:appendRange];

}

- (void)addMessageClient:(id)aClient

{

if(nil == _myListOfClients)
{
    _myListOfClients = [[NSMutableArray alloc] init];
}
[_myListOfClients addObject:aClient];
NSLog(@"Added client");

}

- (BOOL)removeMessageClient:(id)aClient

{

[_myListOfClients removeObject:aClient];
NSLog(@"Removed client");
return YES;

}

- (void)broadcastMessageString:(NSString *)aString

{

NSLog(@"Msg is %@",aString);
self.logStatement = aString;
[_myListOfClients makeObjectsPerformSelector:@selector(appendMessageString:)
                                  withObject:aString];

}

@protocol MYMessageServerProtocol
- (void)addMessageClient:(id)aClient;
- (BOOL)removeMessageClient:(id)aClient;
- (void)broadcastMessageString:(NSString *)aString;

Answer 1

您还没有展示MYMessageServer或MYMessageServerProtocol的代码，特别是-addMessageClient:方法。但是，一旦您向服务器传递了对客户端中某个对象的引用，服务器就可以像往常一样向该对象发送消息，并且该消息将通过D.O.发送给客户端。

因此，客户端通过self向服务器发送-addMessageClient: (其应用程序委托)。服务器可以简单地调用它在-addMessageClient:实现中接收到的对象上的方法，这将调用客户端的应用程序委托对象上的方法。服务器可以将该引用保存在某个地方，例如实例变量中的客户端数组，并在以后的时间继续向客户机发送消息(如果需要的话)。服务器希望在连接关闭时清除该引用，它可以从NSConnection发布的通知中检测到该引用。