如何在 JUnit4 中发送广播？

如何解决如何在 JUnit4 中发送广播？

我有一个活动来处理我想为其编写测试的广播。我已经创建了运行的测试，但是我在广播管理器上得到了一个空对象引用。

这是我的代码：

@RunWith(AndroidJUnit4.class)
public class ManualMoveActivityTest {
    @Rule
    public ActivityTestRule<ManualMoveActivity> activityTestRule =
            new ActivityTestRule<ManualMoveActivity>(ManualMoveActivity.class);

    @Test
    public void FirstScan_ShouldSetSource() {
        Intent i = new Intent();
        i.setAction(ScannerService.ACTION_BARCODE);
        i.putExtra(ScannerService.EXTRA_BARCODE,"CODE");

        LocalbroadcastManager.getInstance(getContext()).sendbroadcast(i);

        Assert.assertEquals(10,activityTestRule.getActivity().gettest());
    }
}

我得到的消息是这样的：

java.lang.NullPointerException: Attempt to invoke virtual method 'android.os.Looper android.content.Context.getMainLooper()' on a null object reference
    at androidx.localbroadcastmanager.content.LocalbroadcastManager.<init>(LocalbroadcastManager.java:115)
    at androidx.localbroadcastmanager.content.LocalbroadcastManager.getInstance(LocalbroadcastManager.java:107)
    at nl.minerall.sapphire.pocket.activities.ManualMoveActivityTest.FirstScan_ShouldSetSource(ManualMoveActivityTest.java:30)
    at java.lang.reflect.Method.invoke(Native Method)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at androidx.test.rule.ActivityTestRule$ActivityStatement.evaluate(ActivityTestRule.java:549)
    at org.junit.rules.RunRules.evaluate(RunRules.java:20)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runchild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runchild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runchildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at androidx.test.runner.AndroidJUnit4.run(AndroidJUnit4.java:104)
    at org.junit.runners.Suite.runchild(Suite.java:128)
    at org.junit.runners.Suite.runchild(Suite.java:27)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runchildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
    at androidx.test.internal.runner.TestExecutor.execute(TestExecutor.java:56)
    at androidx.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:395)
    at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:2205)