我正在开发我的第一个Android应用程序。我的应用程序中有三个活动,并且用户经常在这些活动之间切换。我还有一个远程服务,处理telnet连接。应用程序需要绑定到此服务才能发送/接收telnet消息。
编辑
感谢BDLS提供的详细答案。在您对bindService()
作为独立函数或在startService()
之后使用的区别进行了澄清后,我重新编写了代码,现在仅在使用返回按钮循环浏览活动时偶尔出现泄漏错误消息。
我的连接活动具有以下onCreate()
和onDestroy()
:
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
/*
* Initialize the ServiceConnection. Note that this is the only place startService() is run.
* It is also the only time bindService is run without dependency on connectStatus.
*/
conn = new TelnetServiceConnection();
//start the service which handles telnet
Intent i = new Intent();
i.setClassName( "com.wingedvictorydesign.LightfactoryRemote", "com.wingedvictorydesign.LightfactoryRemote.TelnetService" );
startService(i);
//bind to the service
bindService(i, conn, 0);
setContentView(R.layout.connect);
setupConnectUI();
}//end OnCreate()
@Override
protected void onDestroy() {
super.onDestroy();
//unbind the service and null it out
if (conn != null) {
unbindService(conn);
conn = null;
}
if(connectStatus == 0) {
//stop the service
Intent i = new Intent();
i.setClassName( "com.wingedvictorydesign.LightfactoryRemote", "com.wingedvictorydesign.LightfactoryRemote.TelnetService" );
stopService(i);
Log.d("LightfactoryRemote", "Connect onDestroy() attempted to stop service");
}
Log.d("LightfactoryRemote", "Connect onDestroy()");
}//end onDestroy()
因此,服务在活动启动时启动,在未成功建立telnet连接的情况下(connectStatus == 0
)在活动销毁时停止。其他活动仅在成功建立连接(connectStatus == 1
,保存到共享首选项)后绑定到该服务。这是它们的 onResume()
和 onDestroy()
:
@Override
protected void onResume() {
super.onResume();
//retrieve the shared preferences file, and grab the connectionStatus out of it.
SharedPreferences settings = getSharedPreferences(PREFS_NAME, MODE_WORLD_WRITEABLE);
connectStatus = settings.getInt("connectStatus", 0);
Log.d("LightfactoryRemote", "Focus onResume with " + connectStatus);
//if a telnet connection is active, start the service and bind to it
if (connectStatus == 1) {
conn = new TelnetServiceConnection();
Intent i = new Intent();
i.setClassName("com.wingedvictorydesign.LightfactoryRemote", "com.wingedvictorydesign.LightfactoryRemote.TelnetService");
bindService(i, conn, 0);
//TODO write restore texview code
}//end if
}//end onResume
@Override
protected void onDestroy() {
super.onDestroy();
//unbind the service and null it out.
if (conn != null) {
Log.d("LightfactoryRemote", "Focus onDestroy() attempted to unbind service");
unbindService(conn);
conn = null;
}
Log.d("LightfactoryRemote", "Focus onDestroy()");
}//end onDestroy()
所以绑定发生在 onResume()
中,这样它就可以从连接活动中获取更改后的状态,在 onDestroy()
函数中解除绑定(如果必要)。
编辑结束
但是我仍然会不时地收到“Activity has leaked ServiceConnection @438030a8 that was originally bound here”内存泄漏错误消息,当切换活动时。
我做错了什么?
以下是完整的错误消息(来自修改后的代码):
01-02 22:04:26.642: DEBUG/LightfactoryRemote(2024): Focus onStop()
01-02 22:04:26.642: DEBUG/LightfactoryRemote(2024): Focus onDestroy() attempted to unbind service
01-02 22:04:26.642: DEBUG/LightfactoryRemote(2024): Focus onDestroy()
01-02 22:04:26.672: ERROR/ActivityThread(2024): Activity com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote has leaked ServiceConnection com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote$TelnetServiceConnection@439e51e8 that was originally bound here
01-02 22:04:26.672: ERROR/ActivityThread(2024): android.app.ServiceConnectionLeaked: Activity com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote has leaked ServiceConnection com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote$TelnetServiceConnection@439e51e8 that was originally bound here
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.ActivityThread$PackageInfo$ServiceDispatcher.<init>(ActivityThread.java:927)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.ActivityThread$PackageInfo.getServiceDispatcher(ActivityThread.java:822)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.ApplicationContext.bindService(ApplicationContext.java:842)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.content.ContextWrapper.bindService(ContextWrapper.java:319)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote.onResume(LightfactoryRemote.java:102)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1225)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.Activity.performResume(Activity.java:3559)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2838)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2866)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2420)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.ActivityThread.access$2100(ActivityThread.java:116)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.os.Handler.dispatchMessage(Handler.java:99)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.os.Looper.loop(Looper.java:123)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at android.app.ActivityThread.main(ActivityThread.java:4203)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at java.lang.reflect.Method.invokeNative(Native Method)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at java.lang.reflect.Method.invoke(Method.java:521)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at dalvik.system.NativeStart.main(Native Method)
01-02 22:04:26.692: WARN/ActivityManager(558): Unbind failed: could not find connection for android.os.BinderProxy@43c509a8
编辑第二次
再次感谢bdls的建议。我按照您的建议添加了一个onUnBind()
覆盖到服务中。onUnBind()
实际上只有在所有客户端断开与服务之间的连接时才会被触发,但当我按下主页按钮时,它被执行,然后错误消息弹出!这对我来说毫无意义,因为所有客户端都已从服务中解绑,那么被销毁的一个如何泄漏serviceConnection呢?看看这个:
01-03 19:38:30.837: DEBUG/LightfactoryRemote(1118): Focus onPause()1
01-03 19:38:31.577: WARN/IInputConnectionWrapper(1118): showStatusIcon on inactive InputConnection
01-03 19:38:31.587: DEBUG/LightfactoryRemote(1118): Focus onStop()
01-03 19:38:31.600: DEBUG/LightfactoryRemote(1118): Focus onDestroy() attempted to unbind service
01-03 19:38:31.607: DEBUG/LightfactoryRemote(1118): Focus onDestroy()
01-03 19:38:31.677: DEBUG/LightfactoryRemote(1125): TelnetService onUnBind()
01-03 19:38:31.727: ERROR/ActivityThread(1118): Activity com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote has leaked ServiceConnection com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote$TelnetServiceConnection@435baeb0 that was originally bound here
01-03 19:38:31.727: ERROR/ActivityThread(1118): android.app.ServiceConnectionLeaked: Activity com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote has leaked ServiceConnection com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote$TelnetServiceConnection@435baeb0 that was originally bound here
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.ActivityThread$PackageInfo$ServiceDispatcher.<init>(ActivityThread.java:886)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.ActivityThread$PackageInfo.getServiceDispatcher(ActivityThread.java:781)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.ApplicationContext.bindService(ApplicationContext.java:820)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.content.ContextWrapper.bindService(ContextWrapper.java:307)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote.onResume(LightfactoryRemote.java:102)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1225)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.Activity.performResume(Activity.java:3530)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2619)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2647)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2287)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.ActivityThread.access$1800(ActivityThread.java:112)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1692)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.os.Handler.dispatchMessage(Handler.java:99)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.os.Looper.loop(Looper.java:123)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at android.app.ActivityThread.main(ActivityThread.java:3948)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at java.lang.reflect.Method.invokeNative(Native Method)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at java.lang.reflect.Method.invoke(Method.java:521)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:782)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:540)
01-03 19:38:31.727: ERROR/ActivityThread(1118): at dalvik.system.NativeStart.main(Native Method)
01-03 19:38:31.777: WARN/ActivityManager(564): Unbind failed: could not find connection for android.os.BinderProxy@4370f8a8
我认为可能像你所说的那样,当调用unbindService()
时,与服务的绑定尚未完成,但是我尝试在每个活动返回时调用服务上的方法来验证绑定是否完成,它们都通过了。
总的来说,这种行为似乎与我在每个活动中停留的时间无关。然而,一旦第一个活动泄漏其serviceConnection,之后我回退到它们中的所有活动都会出现同样的问题。
还有一件事,如果我在Dev Tools中打开“立即销毁活动”,它就可以防止这种错误。
有什么想法吗?