Android 为什么PackageManager不能从检测注册表（UI自动机）中找到活动？

为什么来自检测注册表UI automator的PackageManager找不到活动

意图{pkg=com.me.Activity1}

我的申请有3个入口点。三个活动，每个活动由一个图标表示

我正在尝试运行ui自动机测试，以按下图标并启动相应的活动

在Android Studio 2.2中，当我选择app并按Run时，它会正确运行并启动活动。但是，在ui自动机中，它在Nexus 5设备和模拟器上都失败

但是，按照文档中提供的示例，意图为空。 我发现了这一点，并试图修改。由于意图是显式创建的，因此它不再为null，但它不会启动活动-logcat显示它没有启动

调试显示resolveInfos.size为零。我猜上下文或检测注册表有问题

    Collections.sort(resolveInfos, new ResolveInfo.DisplayNameComparator(pm));

我也试过。。。getTargetContext而不是getContext，但失败

    Context context = InstrumentationRegistry.getTargetContext();

谢谢你的帮助

@Test
public void userLaunchesActivity1() {
    launchApp("com.me.Activity1");
}

   void launchApp(String BASIC_SAMPLE_PACKAGE) {
        Log.d("userLaunchesActivity1", "BASIC_SAMPLE_PACKAGE:"+BASIC_SAMPLE_PACKAGE);
        // Initialize UiDevice instance
        mDevice = UiDevice.getInstance(InstrumentationRegistry.getInstrumentation());

    // Start from the home screen
    mDevice.pressHome();

    // Wait for launcher
    final String launcherPackage = mDevice.getLauncherPackageName();
    assertThat(launcherPackage, notNullValue());
    mDevice.wait(Until.hasObject(By.pkg(launcherPackage).depth(0)),
            LAUNCH_TIMEOUT);

    // Launch the app
    Context context = InstrumentationRegistry.getContext();
    // ======== example from android.com documentation - intent is null ====
    // Description
   // final Intent intent = context.getPackageManager()
     //       .getLaunchIntentForPackage(BASIC_SAMPLE_PACKAGE);
    // Clear out any previous instances
    //intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
    //context.startActivity(intent);
    //

    //=======stack overflow answer - does not launch activity====================
    Intent intent = new Intent();
    intent.setPackage(BASIC_SAMPLE_PACKAGE);

    PackageManager pm = context.getPackageManager();
    List<ResolveInfo> resolveInfos = pm.queryIntentActivities(intent, 0);
    Collections.sort(resolveInfos, new ResolveInfo.DisplayNameComparator(pm));

    //======= this is not entered at all ===================
    if(resolveInfos.size() > 0) {
        ResolveInfo launchable = resolveInfos.get(0);
        ActivityInfo activity = launchable.activityInfo;
        ComponentName name = new ComponentName(activity.applicationInfo.packageName,
                activity.name);
        Intent i = new Intent(Intent.ACTION_MAIN);

        i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
        i.setComponent(name);

        context.startActivity(i);
    }
    //===========================

    // Wait for the app to appear
    mDevice.wait(Until.hasObject(By.pkg(BASIC_SAMPLE_PACKAGE).depth(0)),
            LAUNCH_TIMEOUT);
}