什么时候调用Application的onCreate()方法? [英] When does Application's onCreate() method get called?

问题描述

在我的Android应用程序中，我有一个DefaultApplication类扩展了android.app.Application，在其onCreate()中，我绑定了一些服务，这些服务将由该应用程序中的其他活动使用.

In my Android application, I have a DefaultApplication class which extends android.app.Application, and in its onCreate() I bind some services which will be used by my other Activities in this app.

我还有一个BroadcastReceiver，它监听和接收C2DM消息.当接收方在应用程序未运行时收到消息时，它将触发一个对话框，其中显示即将出现的消息，并将启动我的应用程序的活动.

Also I have a BroadcastReceiver which listens and receives C2DM Messages. When this receiver receives a message when the application is not running, it will fire a dialog which shows the upcoming message and it will start an Activity of my application.

我的问题是，当我在不与DefaultApplication进行任何交互的情况下启动活动时，由于该应用程序的活动已启动，我的DefaultApplication的onCreate()是否会被调用?

My question is, when I start an activity without any interaction with DefaultApplication, will my DefaultApplication's onCreate() get called because an Activity of that application has started?

这是我的DefaultApplication的定义和清单:

Here are the definition and Manifest of my DefaultApplication:

public class DefaultApplication extends Application {

    @Override
    public void onCreate() {
        super.onCreate();

        doBindService();

    }

    void doBindService() {

        // Establish a connection with the service. We use an explicit
        // class name because we want a specific service implementation that
        // we know will be running in our own process (and thus won't be
        // supporting component replacement by other applications).

        bindService(new Intent(DefaultApplication.this, SocketService.class),
                socketServiceConnection, Context.BIND_AUTO_CREATE);

        mIsBound = true;
    }

    void doUnbindService() {
        if (mIsBound) {
            // Detach our existing connection.
            unbindService(socketServiceConnection);
            mIsBound = false;
        }
    }
}

清单看起来像这样:

<application android:icon="@drawable/icon" android:label="@string/app_name"
        android:name="com.mypackage.DefaultApplication"
        android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
        android:debuggable="true">
<service android:name="com.mypackage.services.SocketService"></service>
<activity android:name="TestActivity"
            android:screenOrientation="landscape"></activity>
</application>

推荐答案

只有第一次.

启动Activity且未加载应用程序时，将同时调用两个onCreate()方法.

When Activity is started and application is not loaded, then both onCreate() methods will be called.

但是对于后续的Activity启动，将不会调用应用程序的onCreate().

But for subsequent starts of Activity, the onCreate() of application will not be called.

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