小编Ume*_*sif的帖子

我已经筋疲力尽了4天让我的listview滚动但我不能然后有人建议使用RecyclerView,因为我使用的是CoordinatorLayout所以我做了.现在了解并实施RecyclerView之后仍然存在同样的错误.它现在不滚动我应该做什么??? 我想放弃.我无处可去.

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_contacts_list, container, false);
    DataBaseOperations hell = new DataBaseOperations(getActivity());
    SQLiteDatabase db = hell.getReadableDatabase();
    String[] columns = {mDatabase.Tableinfo.ID,mDatabase.Tableinfo.Contacts_phone,mDatabase.Tableinfo.Contacts_name,mDatabase.Tableinfo.Contact_pic};
    Cursor Contacts = db.query(mDatabase.Tableinfo.contacts, columns, null, null, null, null, null);
    Toast.makeText(getContext(),"come on"+Contacts.getCount(),Toast.LENGTH_SHORT).show();
    RecyclerView contacts = (RecyclerView) view.findViewById(R.id.contacts);
    contacts.hasFixedSize();
        RecyclerView.LayoutManager llv = new LinearLayoutManager(getContext(),LinearLayoutManager.VERTICAL,false);
        contacts.setLayoutManager(llv);
        Context t = getContext();
        MyContactsRecyclerViewAdapter lv = new MyContactsRecyclerViewAdapter(Contacts,t);
        contacts.setAdapter(lv);

            return view;
}

这里是我的list.xml的xml,它是在寻呼机,如果我也发布代码????

<android.support.v7.widget.RecyclerView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/contacts"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginLeft="16dp"
    android:layout_marginRight="16dp"
    android:scrollbars="vertical"
     tools:listitem="@layout/fragment_contacts" /> …

我正在尝试从Gallery中获取图像并将其设置为imageview,但在Android 6中存在一些权限问题.以下是要求许可的方法.我应该要求读外部存储还是写外部存储？

这是我到目前为止所做的:

    private static final int READ_CONTACTS_PERMISSIONS_REQUEST = 1;


    public void getPermissionToReadExternalStorage() {

    if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.READ_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED) {

        if (shouldShowRequestPermissionRationale(
                Manifest.permission.READ_EXTERNAL_STORAGE)) {

            requestPermissions(new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
                    READ_CONTACTS_PERMISSIONS_REQUEST);
        }}}
    @Override
            public void onRequestPermissionsResult(int requestCode,
                                                   @NonNull String permissions[],
                                                   @NonNull int[] grantResults){
                // Make sure it's our original READ_CONTACTS request
                if (requestCode == READ_CONTACTS_PERMISSIONS_REQUEST) {
                    if (grantResults.length == 1 &&
                            grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                        Toast.makeText(getActivity(), "Read Contacts permission granted", Toast.LENGTH_SHORT).show();

                    } else {
                        Toast.makeText(getActivity(), "Read Contacts permission denied", Toast.LENGTH_SHORT).show();
                    }
                } else { …