小编Rea*_*hed的帖子

我花了一些时间试图找出一种方法来添加一个标题RecyclerView,但没有成功.这是我到目前为止所得到的:

@Override
protected void onCreate(Bundle savedInstanceState) {
    ...

    layouManager = new LinearLayoutManager(getActivity());
    recyclerView.setLayoutManager(layouManager);

    LayoutInflater inflater = (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    headerPlaceHolder = inflater.inflate(R.layout.view_header_holder_medium, null, false);
    layouManager.addView(headerPlaceHolder, 0);

   ...
}

在LayoutManager似乎是处理的配置对象RecyclerView的项目.因为我无法找到任何addHeaderView(View view)方法,我决定去与LayoutManager的addView(View view, int position)方法,并增加我的头鉴于第一位置,像一个头.

Aaand这是事情变得更加丑陋的地方:

java.lang.NullPointerException: Attempt to read from field 'android.support.v7.widget.RecyclerView$ViewHolder android.support.v7.widget.RecyclerView$LayoutParams.mViewHolder' on a null object reference
    at android.support.v7.widget.RecyclerView.getChildViewHolderInt(RecyclerView.java:2497)
    at android.support.v7.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:4807)
    at android.support.v7.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:4803)
    at com.mathieumaree.showz.fragments.CategoryFragment.setRecyclerView(CategoryFragment.java:231)
    at com.mathieumaree.showz.fragments.CategoryFragment.access$200(CategoryFragment.java:47)
    at com.mathieumaree.showz.fragments.CategoryFragment$2.success(CategoryFragment.java:201)
    at com.mathieumaree.showz.fragments.CategoryFragment$2.success(CategoryFragment.java:196)
    at retrofit.CallbackRunnable$1.run(CallbackRunnable.java:41)
    at android.os.Handler.handleCallback(Handler.java:739)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:135) …

我希望所有来自Firebase的子列表都在android中.

我已经实现了这个代码,但它不起作用.

mFirebaseRef = new Firebase(FIREBASE_URL);

mFirebaseRef.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        List<String> td = (ArrayList<String>) dataSnapshot.getValue();
        //notifyDataSetChanged();
    }

    @Override
    public void onCancelled(FirebaseError firebaseError) {

    }
});

有人可以给我一个关于如何使用maven-publish gradle插件发布带有aar和source jar的com.android.library项目/模块的提示吗？我可以使用旧的maven插件执行此操作 - 但我想使用新的maven-publish插件.

我打算开发一个应用程序,在其中显示一些动态数据recyclerCardView.所以我决定 在我的主要内部添加一个recyclerView名字.这是我的应用程序的代码:CheckBoxRecyclerViewrecyclerView

我的主要活动:

setContentView(R.layout.activity_startup);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
reminderView = (RecyclerView) findViewById(R.id.reminder_recycler_view);
RlayoutManager = new LinearLayoutManager(this);
reminderView.setLayoutManager(RlayoutManager);

setSupportActionBar(toolbar);
cardView = (CardView) findViewById(R.id.card_first);
cardView.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Intent intent = new Intent(getApplicationContext() , ReminderActivity.class);
        startActivity(intent);
    }
});
ReminderHelper helper = new ReminderHelper(getApplicationContext());
ReminderAdapter reminderAdapter = new ReminderAdapter(helper);
ContentValues reminderValues = new ContentValues();
ContentValues checkboxValues = new ContentValues();
// Devlopment Part ->
reminderValues.put("reminderTitle" , "A Reminder Title");
reminderValues.put("reminderLastModDate" , 0); …

正如我正在尝试使用带有postman chrome附加组件的spring boot和webservices.

在邮递员content-type="multipart/form-data"和我得到以下例外.

HTTP Status 500 - Request processing failed; 
nested exception is org.springframework.web.multipart.MultipartException: Could not parse multipart servlet request; 
nested exception is java.io.IOException: 
org.apache.tomcat.util.http.fileupload.FileUploadException: the request was rejected because no multipart boundary was found

在Controller中我指定了以下代码

@ResponseBody
@RequestMapping(value = "/file", headers = "Content-Type= multipart/form-data", method = RequestMethod.POST)

public String upload(@RequestParam("name") String name,
        @RequestParam(value = "file", required = true) MultipartFile file)
//@RequestParam ()CommonsMultipartFile[] fileUpload
{
    // @RequestMapping(value="/newDocument", , method = RequestMethod.POST)
    if (!file.isEmpty()) {
        try {
            byte[] fileContent …

我正在开发一个大学项目,让用户在地图上放置一个点,然后设置叠加对象的标题和描述.问题是,第二个EditText框覆盖了第一个框.这是我的对话框代码.

//Make new Dialog
AlertDialog.Builder dialog = new AlertDialog.Builder(mapView.getContext());
dialog.setTitle("Set Target Title & Description");
dialog.setMessage("Title: ");

final EditText titleBox = new EditText(mapView.getContext());
dialog.setView(titleBox);

dialog.setMessage("Description: ");
final EditText descriptionBox = new EditText(mapView.getContext());
dialog.setView(descriptionBox);

任何帮助,将不胜感激!!谢谢!

我们如何知道用户是向下滚动还是向上滚动RecyclerView？

我尝试过RecyclerView#OnScrollListener,它给出了垂直滚动量和滚动状态.滚动状态空闲时,如何在开始拖动和滚动位置时获取最后一个滚动位置.

谢谢.

这似乎是一个简单的解决方案,但似乎设置

private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private LinearLayoutManager mLayoutManager;

.... // More code

    mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recycler_view);

    // Add item decoration
    mRecyclerView.addItemDecoration(new SpacesItemDecoration(DIVIDER_SPACE));

    // use this setting to improve performance if you know that changes
    // in content do not change the layout size of the RecyclerView
    mRecyclerView.setHasFixedSize(true);

    // use a linear layout manager
    mLayoutManager = new LinearLayoutManager(getActivity());
    mLayoutManager.setReverseLayout(true); // THIS ALSO SETS setStackFromBottom to true
    mRecyclerView.setLayoutManager(mLayoutManager);

似乎还要从底部设置要堆叠的项目

我试图设置setStackFromBottom为false但是没有做任何事情,什么是扭转项目顺序但仍然从顶部填充的最佳方法？我应该使用Custom Comparator类吗？我希望这比创建另一个类更容易.

我getBluetoothService() called with no BluetoothManagerCallback在Android应用程序中经常出错.

我不知道是什么导致了这个或任何关于蓝牙管理器回调.任何人都可以让我很好地了解可能导致此问题的原因或从哪里开始寻找.

对于ListView,如果我们想要选择特定项目,我们使用"setSelection"方法.如果是回收商View我们如何做到这一点