启动没有主活动的 Android 应用程序，并在启动应用程序时启动服务

在我的应用程序中有以下场景。在我的应用程序中没有 UI; 取而代之的是一个服务，该服务在启动时启动并将持续运行。

如何在没有主活动的情况下配置清单文件？我可以在没有任何活动的情况下启动我的应用程序吗？在启动我的应用程序时，我的服务应该启动。这可能吗？

我不想做一个半透明的活动来启动服务。

120210 次浏览
小开
最佳答案

You said you didn't want to use a translucent Activity, but that seems to be the best way to do this:

  1. In your Manifest, set the Activity theme to Theme.Translucent.NoTitleBar.
  2. Don't bother with a layout for your Activity, and don't call setContentView().
  3. In your Activity's onCreate(), start your Service with startService().
  4. Exit the Activity with finish() once you've started the Service.

In other words, your Activity doesn't have to be visible; it can simply make sure your Service is running and then exit, which sounds like what you want.

I would highly recommend showing at least a Toast notification indicating to the user that you are launching the Service, or that it is already running. It is very bad user experience to have a launcher icon that appears to do nothing when you press it.

小开

Yes you can do that by just creating a BroadcastReceiver that calls your Service when your Application boots. Here is a complete answer given by me.
Android - Start service on boot

If you don't want any icon/launcher for you Application you can do that also, just don't create any Activity with

<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>

Just declare your Service as declared normally.

小开

Android Studio Version 2.3

You can create a Service without a Main Activity by following a few easy steps. You'll be able to install this app through Android Studio and debug it like a normal app.

First, create a project in Android Studio without an activity. Then create your Service class and add the service to your AndroidManifest.xml

<application android:allowBackup="true"
android:label="@string/app_name"
android:icon="@mipmap/ic_launcher"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/AppTheme">
<service android:name="com.whatever.myservice.MyService">
<intent-filter>
<action android:name="com.whatever.myservice.MyService" />
</intent-filter>
</service>
</application>

Now, in the drop down next to the "Run" button(green arrow), go to "edit configurations" and within the "Launch Options" choose "Nothing". This will allow you to install your Service without Android Studio complaining about not having a Main Activity.

Once installed, the service will NOT be running but you will be able to start it with this adb shell command...

am startservice -n com.whatever.myservice/.MyService

Can check it's running with...

ps | grep whatever

I haven't tried yet but you can likely have Android Studio automatically start the service too. This would be done in that "Edit Configurations" menu.

小开

The reason to make an App with no activity or service could be making a Homescreen Widget app that doesn't need to be started.
Once you start a project don't create any activities. After you created the project just hit run. Android studio will say No default activity found.

Click Edit Configuration (From the Run menu) and in the Launch option part set the Launch value to Nothing. Then click ok and run the App.

NOTE: Since the app has no launcher activity, no icon will be shown in the apps menu. Instead, look for it in device's App manager.


提交答案