mUserListLayoutManager = new LinearLayoutManager(getApplicationContext(), LinearLayout.VERTICAL, false);不工作答案

【问题标题】：mUserListLayoutManager = new LinearLayoutManager(getApplicationContext(), LinearLayout.VERTICAL, false); not workingmUserListLayoutManager = new LinearLayoutManager(getApplicationContext(), LinearLayout.VERTICAL, false);不工作
【发布时间】：2020-02-21 16:01:27
【问题描述】：

/*JAVA File*/ArrayList<UserObject> userList;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_find_user);

    initializeRecyclerView();

}

private void initializeRecyclerView() {
    mUserList=findViewById(R.id.userList);
    mUserList.setNestedScrollingEnabled(false);
    mUserList.setHasFixedSize(false);
    mUserListLayoutManager = new LinearLayoutManager(getApplicationContext(), LinearLayout.VERTICAL, false);
    mUserList.setLayoutManager(mUserListLayoutManager);
    mUserListAdapter =new UserList(userList);
    mUserList.setAdapter(mUserListAdapter);
}

XML 文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".FindUserActivity">


<androidx.recyclerview.widget.RecyclerView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/userList"
    android:scrollbars="vertical">

</androidx.recyclerview.widget.RecyclerView>

线：mUserListLayoutManager = new LinearLayoutManager(getApplicationContext(), LinearLayout.VERTICAL, false);

提供警告：必须是 RecyclerView.HORIZONTAL 或 RecyclerView.VERTICAL 之一问题 ID：错误常量

【问题讨论】：

标签： java android android-studio

【解决方案1】：

您应该使用在RecyclerView 中定义的常量作为方向：

mUserListLayoutManager = new LinearLayoutManager(getApplicationContext(), RecyclerView.VERTICAL, false);

【讨论】：

【解决方案2】：

你应该使用这一行：

mUserListLayoutManager = new LinearLayoutManager(getApplicationContext(), 
RecyclerView.VERTICAL, false);

那么你的代码一定是这样的：

private void initializeRecyclerView() {
    mUserList=findViewById(R.id.userList);
    mUserList.setNestedScrollingEnabled(false);
    mUserList.setHasFixedSize(false);
    mUserListLayoutManager = new LinearLayoutManager(getApplicationContext(), 
         RecyclerView.VERTICAL, false);
    mUserList.setLayoutManager(mUserListLayoutManager);
    mUserListAdapter =new UserList(userList);
    mUserList.setAdapter(mUserListAdapter);
}

【讨论】：