小编kol*_*ach的帖子

是否可以onClick使用数据绑定库将自定义参数传递给方法？我有我的布局xml文件,我需要使用onClickListener:

<?xml version="1.0" encoding="utf-8"?>
<layout ...>

    <data>
        <variable
            name="viewModel"
            type="com.productivity.tiktak.ui.tracker.viewModel.CategoryViewModel"/>
        <variable
            name="callback"
            type="com.productivity.tiktak.ui.tracker.TrackerAdapter"/>
    </data>

    <android.support.v7.widget.CardView
        android:onClick="@{callback.onCategoryClick(viewModel)}"
        ...
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

       <!-- ... Some stuff -->

    </android.support.v7.widget.CardView>
</layout>

我在这里有我的点击处理程序代码:

public void onCategoryClick(View view, CategoryViewModel categoryViewModel)
{
    //handler code...
}

是否可以将我的CategoryViewModel对象从xml传递到单击处理程序？

当用户靠近给定地点时，我需要通知他。我为此使用地理围栏 API。当我使用模拟位置在 Android 模拟器上测试应用程序时，一切正常。对于带有模拟位置的真实设备也是如此。但是，当我走路并且手机处于深度睡眠模式时，地理围栏会在 5 - 10 分钟后触发。如果我在地理围栏半径内并且解锁手机，请打开任何使用地理围栏立即触发的位置的应用程序。（Android 5.1、摩托罗拉 moto G 第一代）

以下是我注册地理围栏的方式：

  public void registerLocation(RegisterAlarmRequestModel data) {
    if (isLocationDetectionAllowed() && isConnected) {
        GeofencingRequest geofencingRequest = prepareGeofencingRequest(prepareGeofence(data));
        PendingIntent pendingIntent = prepareIntent(data.getId());
        PendingResult<Status> result = GeofencingApi.addGeofences(
                googleApiClient, geofencingRequest, pendingIntent);
        Status status = result.await();
        if (status.isSuccess())
            Log.d("Location", "Geofence " + data.getId() + " has been registered");
    }
}

//preparing Geofence Pending Intent which will be triggered 
private PendingIntent prepareIntent(int alarmId) {
    Intent intent = new Intent(context, LocationRingingService.class);
    intent.putExtra(LocationRingingService.KEY_ALARM_ID, alarmId);
    return PendingIntent.getService(context, 0, …

当我尝试在片段类中为Notificatoin Manager分配值时,我有Null Pointer Exception.

    private NotificationManager m_notificationMgr;

public void CreateNotification() {
    Log.d(TAG, "created");

    m_stopwatch = new Stopwatch();
    m_notificationMgr = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);//null pointer exception

    createNotification();
    Log.d(TAG, "ok");
}

错误日志

05-15 12:31:16.127: E/AndroidRuntime(2216): FATAL EXCEPTION: main
05-15 12:31:16.127: E/AndroidRuntime(2216): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.timetracker/com.example.timetracker.MainActivity}: java.lang.NullPointerException
05-15 12:31:16.127: E/AndroidRuntime(2216):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211)
05-15 12:31:16.127: E/AndroidRuntime(2216):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
05-15 12:31:16.127: E/AndroidRuntime(2216):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-15 12:31:16.127: E/AndroidRuntime(2216):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
05-15 12:31:16.127: E/AndroidRuntime(2216):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-15 12:31:16.127: E/AndroidRuntime(2216):     at android.os.Looper.loop(Looper.java:137)
05-15 12:31:16.127: E/AndroidRuntime(2216):     at android.app.ActivityThread.main(ActivityThread.java:5103)
05-15 12:31:16.127: …