android - InputMethodService 的仪器测试用例

Question

我已经扩展了 InputMethodService类来创建我的自定义 IME。但是，我正在努力编写有效的 Instrumentation 测试用例来验证行为。以前是 Service , 可以使用 ServiceTestCase<YourServiceClass> 进行测试.但它似乎已被弃用，新格式看起来像 this .现在在给定的指导方针中，我正在努力处理这个 fragment :

CustomKeyboardService service =
            ((CustomKeyboardService.LocalBinder) binder).getService();

因为我要扩展 InputMethodService , 它已经抽象出 IBinder , 我怎样才能获得 LocalBinder让这段代码运行？目前，此代码段抛出以下异常:

java.lang.ClassCastException: android.inputmethodservice.IInputMethodWrapper cannot be cast to com.osrc.zdar.customkeyboard.CustomKeyboardService$LocalBinder

扩展类如下所示:

public class CustomKeyboardService extends InputMethodService {

    // Some keyboard related stuff

    public class LocalBinder extends Binder {

        public CustomKeyboardService getService() {
            // Return this instance of LocalService so clients can call public methods.
            return CustomKeyboardService.this;
        }
    }

    // Some keyboard related stuff

}

我如何扩展我的自定义类使得 CustomKeyboardService service = ((CustomKeyboardService.LocalBinder) binder).getService();不返回错误？

这是我的测试用例代码:

@RunWith(AndroidJUnit4.class)
public class ExampleInstrumentedTest2 {
    @Rule
    public final ServiceTestRule mServiceRule = new ServiceTestRule();

    @Test
    public void testWithBoundService() throws TimeoutException {
        // Create the service Intent.
        Intent serviceIntent =
                new Intent(InstrumentationRegistry.getTargetContext(), CustomKeyboardService.class);

        // Bind the service and grab a reference to the binder.
        IBinder binder = mServiceRule.bindService(serviceIntent);

        // Get the reference to the service, or you can call public methods on the binder directly.
        //  This Line throws the error
        CustomKeyboardService service =
                ((CustomKeyboardService.LocalBinder) binder).getService();
    }

}

您还可以查看 OimeKeyboard在 Github 上获取完整的源代码，并提交带有有效仪器测试用例的 PR。

Answer 1

同样的问题发生在我身上，请查看下面链接的解决方案。
更新了链接中的代码 fragment :

@Rule
public final ServiceTestRule mServiceRule = new ServiceTestRule();

private MyKeyboard retrieveMyKeyboardInstance(IBinder binder) {
    try {
        Class wrapperClass = Class.forName("android.inputmethodservice.IInputMethodWrapper");
        Field mTargetField = wrapperClass.getDeclaredField("mTarget");
        mTargetField.setAccessible(true);

        WeakReference<MyKeyboard> weakReference = (WeakReference<MyKeyboard>) mTargetField.get(binder);
        return weakReference.get();
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}

public void validateEditTextWithKeyboardInput() throws TimeoutException {
    ...
    Intent serviceIntent = new Intent(InstrumentationRegistry.getTargetContext(), MyKeyboard.class);
    IBinder binder = mServiceRule.bindService(serviceIntent);
    MyKeyboard keyboard = retrieveMyKeyboardInstance(binder);

    ...
}

发件人:https://github.com/sealor/prototype-Android-Espresso-Keyboard-Testing