Question

我有一个使用https://github.com/googlesamples/android-Camera2Video示例的Cordova插件。我想在相机中禁用后退按钮。

要做到这一点，我相信Fragments不能接受后退按钮事件，所以已经为插件添加了一个Activity。我可以成功运行插件，相机和活动，禁用后退按钮。

然而，当我关闭插件时，它出现错误：

java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState

为了解决这个问题，我使用了commitAllowingStateLoss而不是commit但是当我第二次打开插件时，它出错了：

java.lang.NullPointerException: Attempt to invoke interface method 'android.app.Activity org.apache.cordova.CordovaInterface.getActivity()' on a null object reference

我认为我没有正确停止活动，并且允许状态丢失，这会导致第二个错误。我该如何解决这个问题？

我尝试过这种方法，但没有运气： PhoneGap Android Plugin - close the plugin Activity

我已将我的代码放在此处的分支中： https://github.com/kmturley/cordova-plugin-media-custom/tree/feature/back-button

添加更改摘要：

的plugin.xml

<config-file target="AndroidManifest.xml" parent="/manifest/application">
    <activity android:name="com.example.android.camera2video.MediaCustomActivity" android:label="@string/activity_name" android:theme="@style/Theme.Transparent">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</config-file>
<source-file src="src/android/MediaCustom.java" target-dir="src/com/example/android/camera2video" />
<source-file src="src/android/MediaCustomActivity.java" target-dir="src/com/example/android/camera2video" />
<source-file src="src/android/Camera2VideoFragment.java" target-dir="src/com/example/android/camera2video" />

MediaCustom.java

public void show() {
    if (cameraFragment != null) {
        return;
    }
    cameraFragment = Camera2VideoFragment.newInstance(cordova, callbackContext);
    cordova.getActivity().runOnUiThread(new Runnable() {
         @Override
         public void run() {
            cordova.getActivity().setContentView(resources.getIdentifier("activity_camera", "layout", packageName));
            FragmentManager fragmentManager = cordova.getActivity().getFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
            fragmentTransaction.replace(resources.getIdentifier("container", "id", packageName), cameraFragment);
            fragmentTransaction.commit();

            MediaCustomActivity.start(cordova.getActivity());
        }
    });
}

public void hide() {
    if (cameraFragment == null) {
        return;
    }
    cordova.getActivity().runOnUiThread(new Runnable() {
        @Override
        public void run() {
            MediaCustomActivity.stop(cordova.getActivity());

            cordova.getActivity().setContentView(getView());
            FragmentManager fragmentManager = cordova.getActivity().getFragmentManager();
            FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
            fragmentTransaction.remove(cameraFragment);
            fragmentTransaction.commitAllowingStateLoss(); // commit();
            cameraFragment = null;
        }
    });
}

MediaCustomActivity.java

public static void start(Activity activity) {
    Intent intent = new Intent(activity, MediaCustomActivity.class);
    activity.startActivity(intent);
}

public static void stop(Activity activity) {
    // what can we do here?
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    super.init();

    Window window = this.getWindow();
    window.setFlags(WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE, WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE);
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK) {
        return false;
    }
    return super.onKeyDown(keyCode, event);
}

Cordova插件停止/重新启动活动

0 个答案: