组件回调的问题

[梧桐168]

我写了一个com组件，用javascript来调用其中的一个方法，但调用完之后，我会不断的有返回状态回来，显示在网页上
想问下怎么回调给javascript，或者有什么其它的方法

[梧桐168]

非常感谢楼上各位的回复，我试试看，刚开始搞这 xpcom开发，很多细节还不熟悉

[ccpaishi]

JavaScript是可以接收回调函数的啊，你直接实现回调不行吗？？

[雪影]

js声明一个函数,COM组件内部事件触发时调用该函数.

[梧桐168]

我在网上找到了COM组件中调用JavaScript函数的方法
http://faceye.com/wiki/topic/402881b12625f10601262619531c0748
但我做的是xpcom在mozilla里调用，xpcom里类似的VARIANT是怎么用的

[SullenSun]

up。。

[sgzwiz]

可以采用nsIObserverService接口
https://developer.mozilla.org/en/nsIObserverService

[sgzwiz]

function myObserver()
{
  this.register();
}
myObserver.prototype = {
  observe: function(subject, topic, data) {
     // Do your stuff here.
  },
  register: function() {
    var observerService = Components.classes["@mozilla.org/observer-service;1"]
                          .getService(Components.interfaces.nsIObserverService);
    observerService.addObserver(this, "myTopicID", false);
  },
  unregister: function() {
    var observerService = Components.classes["@mozilla.org/observer-service;1"]
                            .getService(Components.interfaces.nsIObserverService);
    observerService.removeObserver(this, "myTopicID");
  }
}

Instantiation - this should be fired once you're ready to start observing (ex: a window's load event).

observer = new myObserver();

Destruction - this should be fired once you're done observing (ex: a window's unload event). Failure to do so may result in memory leaks.

observer.unregister();

nsresult
nsWebShellWindow::NotifyObservers( const nsString &aTopic, const nsString &someData )  {
    nsresult rv = NS_OK;
    // Get observer service.
    nsIObserverService *svc = 0;
    rv = nsServiceManager::GetService( "@mozilla.org/observer-service;1",
                                       NS_GET_IID(nsIObserverService),
                                       (nsISupports**)&svc );
    if ( NS_SUCCEEDED( rv ) && svc ) {
        // Notify observers as instructed; the subject is "this" web shell window.
        nsCAutoString topic; topic.Assign(prefix);
        topic.Append(";");
        topic.AppendWithConversion(aTopic);
        rv = svc->NotifyObservers( (nsIWebShellWindow*)this, topic.get(), someData.get() );
        // Release the service.
        nsServiceManager::ReleaseService( "@mozilla.org/observer-service;1", svc );
    } else {
    }
    return rv;
} 

[梧桐168]

我写了一个小例子，但没成功，不知道哪里有问题，大致代码如下

NS_IMETHODIMP CMyXPCOM1::NotifyObservers(nsISupports *aSubject, const char *aTopic, const PRUnichar *someData)
{
	if (m_pObserver)
		m_pObserver->Observe(aSubject, aTopic, someData);
	return NS_OK;
}


/* long Add (in long a, in long b); */
NS_IMETHODIMP CMyXPCOM1::Add(PRInt32 a, PRInt32 b, PRInt32 *_retval)
{
	*_retval = a + b;
	NotifyObservers(this, "aaa", L"bbb");
	return NS_OK;
}

[梧桐168]

//*
function myObserver()
{
  this.register();
}

myObserver.prototype = 
{
  observe: function(subject, topic, data) 
  {
    alert('Performing 3+4'); 
  },
  
  register: function() 
  {
    const cid = "@yoursite.com/MyXPCOM1;1";
    var obj = Components.classes[cid].createInstance();
	obj = obj.getService(Components.interfaces.nsIObserverService);
    obj.addObserver(this, "myTopicID", false);
  },
  
  unregister: function() 
  {
    var observerService = Components.classes['@yoursite.com/MyXPCOM1;1'].getService(Components.interfaces.nsIObserverService);
    observerService.removeObserver(this, "myTopicID");
  }
}
//*/
var my_xpcom = null; 
var my_observer = new myObserver(); 
function MyComponentTestGo() 
{    
	try {
		netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
		const cid = "@yoursite.com/MyXPCOM1;1";
		my_xpcom = Components.classes[cid].createInstance();
		my_xpcom = my_xpcom.QueryInterface(Components.interfaces.IMyXPCOM1);
		my_xpcom.observer = my_observer; 

	} catch (err) {
		alert(err);
		return;
	}
	var res = my_xpcom.Add(3, 4);
	alert('Performing 3+4. Returned ' + res + '.');
}

[firmbird]

有这么复杂吗？组件提供一个事件不就行了