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,用户来回切换非常频繁。我还有一个远程服务,可以处理 telnet 连接。应用程序需要绑定到这个服务,以便发送/接收 telnet 消息。
感谢 BDLS 提供的信息性答案。根据您对使用 bindService()
作为独立函数与使用 startService()
之后的区别的说明,我已经重写了我的代码,现在我只是在使用后退按钮在活动之间循环时间歇性地得到泄漏错误消息。
我的连接活动有以下 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,如果没有成功的 telnet 连接(connectStatus == 0
) ,则在活动被销毁时停止。其他活动只有在建立了成功的连接(connectStatus == 1
,保存到共享首选项)时才绑定到服务。这是他们的 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()
因此绑定发生在 onResume()
中,这样它就会从连接活动中获取已更改的状态,而在 onDestroy()
函数中,如果需要的话,它是未绑定的。
结束编辑
但是在切换活动时,我仍然会间歇性地收到内存泄漏错误消息“ Activity 已经泄漏了 ServiceConnection@438030a8,它最初是绑定在这里的”。我做错了什么?
预先感谢任何提示或指导! ! !
完整的错误信息如下(来自修订后的代码) :
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$MethodAndArgsCaller.run(ZygoteInit.java:791)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
01-02 22:04:26.672: ERROR/ActivityThread(2024): at dalvik.system.NativeStart.main(Native Method)
01-02 22:04:26.692: WARN/ActivityManager(558): Unbind failed: could not find connection for android.os.BinderProxy@43c509a8
编辑第二部
再次感谢你的建议。我按照你的建议给服务添加了 onUnBind()
覆盖。onUnBind()
实际上只有当所有客户端从服务断开时才会触发,但是当我点击 home 按钮时,它执行了,然后出现了错误消息!这对我来说毫无意义,因为所有的客户端都已经从服务中解除绑定,那么被销毁的客户端怎么会泄露 serviceConnection 呢?看看这个:
01-03 19:38:30.837: DEBUG/LightfactoryRemote(1118): Focus onPause()1
01-03 19:38:31.577: WARN/IInputConnectionWrapper(1118): showStatusIcon on inactive InputConnection
01-03 19:38:31.587: DEBUG/LightfactoryRemote(1118): Focus onStop()
01-03 19:38:31.600: DEBUG/LightfactoryRemote(1118): Focus onDestroy() attempted to unbind service
01-03 19:38:31.607: DEBUG/LightfactoryRemote(1118): Focus onDestroy()
01-03 19:38:31.677: DEBUG/LightfactoryRemote(1125): TelnetService onUnBind()
01-03 19:38:31.727: ERROR/ActivityThread(1118): Activity com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote has leaked ServiceConnection com.wingedvictorydesign.LightfactoryRemote.LightfactoryRemote$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
我想可能是像你说的那样,当调用 unbindService()
时,到服务的绑定是不完整的,但是我尝试在服务上调用一个方法,当我备份每个活动来验证绑定是完整的时候,它们都通过了。
一般来说,这种行为似乎与我在每个活动中停留的时间无关。然而,一旦第一个活动泄露了它的 serviceConnection,它们就会像我在之后返回它们一样进行操作。
还有一件事,如果我在开发工具中打开“立即销毁活动”,它可以防止这个错误。
有什么想法吗?