【发布时间】：2018-04-16 10:50:24
【问题描述】：
我正在尝试从 MySQL 数据库中填充 RecylerView。我能够使用 volley 库（使用 Toast 测试）正确地从数据库中获取数据，但它没有显示在 RecyclerView 中。我的代码到现在为止。
fragment_notification.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context="in.techbash.androidhiverecyclerview.NotificationFragment">
<!-- TODO: Update blank fragment layout -->
<RelativeLayout
android:id="@+id/relativeLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
<android.support.v7.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical" />
</RelativeLayout>
</FrameLayout>
我的 NotificationFragment 类
NotificationFragment.java
public class NotificationFragment extends Fragment {
private List<Notification> notificationList = new ArrayList<>();
private RecyclerView recyclerView;
NotificationsAdapter notificationsAdapter;
private View rootView;
private RecyclerView.LayoutManager mLayoutManager;
public NotificationFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
rootView = inflater.inflate(R.layout.fragment_notification, container, false);
recyclerView = rootView.findViewById(R.id.recycler_view);
getNotifications();
return rootView;
}
private void getNotifications() {
final String get_notifications = "http://192.168.1.102/notification/get_notifications.php";
final String user_id = "327875";
Map<String, String> parameters = new HashMap<String, String>();
parameters.put("user_id", user_id);
JSONObject jsonObj = new JSONObject(parameters);
JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(Request.Method.POST,
get_notifications, jsonObj, new Response.Listener<JSONObject>() {
@Override
public void onResponse(JSONObject response) {
try {
JSONArray jsonArray = response.getJSONArray("result");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
//adding the product to product list
notificationList.add(new Notification(
jsonObject.getString("msg_title"),
jsonObject.getString("message"),
jsonObject.getString("sender_name")
));
}
//creating adapter object and setting it to recyclerview
NotificationsAdapter adapter = new NotificationsAdapter(getActivity(), notificationList);
recyclerView.setAdapter(adapter);
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
}
}) {
@Override
public String getBodyContentType() {
return "application/json; charset=utf-8";
}
};
MySingleton.getInstance(getActivity()).addToRequestQueue(jsonObjectRequest);
}
}
我的 notification_list_row.xml 文件
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?android:attr/selectableItemBackground"
android:clickable="true"
android:focusable="true"
android:orientation="vertical"
android:paddingBottom="@dimen/row_padding_vertical"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/row_padding_vertical">
<TextView
android:id="@+id/title"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:textColor="@color/title"
android:textSize="16dp"
android:textStyle="bold" />
<TextView
android:id="@+id/message"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/title" />
<TextView
android:id="@+id/sender"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:textColor="@color/year" />
</RelativeLayout>
NotificationsAdapter.java
public class NotificationsAdapter extends
RecyclerView.Adapter<NotificationsAdapter.MyViewHolder> {
private List<Notification> notificationsList;
private Context mCtx;
public NotificationsAdapter(Context mCtx, List<Notification> notificationsList){
this.mCtx = mCtx;
this.notificationsList = notificationsList;
}
@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//inflating and returning our view holder
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.notification_list_row, parent, false);
return new MyViewHolder(view);
}
@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
Notification notification = notificationsList.get(position);
holder.title.setText(notification.getTitle());
holder.message.setText(notification.getMessage());
holder.sender.setText(notification.getSender());
}
@Override
public int getItemCount() {
return notificationsList.size();
}
public class MyViewHolder extends RecyclerView.ViewHolder {
public TextView title, message, sender;
public MyViewHolder(View itemView) {
super(itemView);
title = (TextView) itemView.findViewById(R.id.title);
message = (TextView) itemView.findViewById(R.id.message);
sender = (TextView) itemView.findViewById(R.id.sender);
}
}
}
我的通知获取器/设置器
public class Notification {
String sender, title, message;
public Notification(String title, String message, String sender){
this.title = title;
this.message = message;
this.sender = sender;
}
public String getSender() {
return sender;
}
public void setSender(String sender) {
this.sender = sender;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
}
我是安卓新手。请帮我解决这个问题。
【问题讨论】：
-
面临什么问题？
-
@VishalG.Gohel 数据未显示在 RecyclerView 中。但用 Toast 测试，它显示在里面。
-
缺少布局管理器。
-
向我们展示 logcat 。
标签： android mysql android-volley