Java 在片段内显示从url到listview的json文件
我最近了解了android编程。现在,我打算用json从php获取数据到我的android应用程序 这是我的剧本 Bamanual.javaJava 在片段内显示从url到listview的json文件,java,android,listview,android-fragments,Java,Android,Listview,Android Fragments,我最近了解了android编程。现在,我打算用json从php获取数据到我的android应用程序 这是我的剧本 Bamanual.java package com.example.boby.firstapp; import android.os.AsyncTask; import android.support.v4.app.Fragment; import android.os.Bundle; import android.support.annotation.Nullable; impo
package com.example.boby.firstapp;
import android.os.AsyncTask;
import android.support.v4.app.Fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
public class Bamanual extends Fragment {
ListView listView;
ArrayList<HashMap<String, String>> list_data;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_bamanual, container, false);
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
getActivity().setTitle("Menu Ba Manual");
getJSON("http://192.168.3.223:84/fppb/andro_login/fppb");
}
private void loadIntoListView(String json) throws JSONException {
ArrayList<String> items = new ArrayList<String>();
JSONArray jsonArray = new JSONArray(json);
String[] ba = new String[jsonArray.length()];
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject obj = jsonArray.getJSONObject(i);
String name=obj.getString("ItemCode");
String photo=obj.getString("PhotoName");
items.add(name);
}
ArrayAdapter<String> mArrayAdapter = new ArrayAdapter<String>(getActivity(),android.R.layout.simple_expandable_list_item_1, items);
listView = (ListView) listView.findViewById(R.id.listView1);
listView.setAdapter(mArrayAdapter);
//Toast.makeText(getActivity(), jsonArray.toString(), Toast.LENGTH_LONG).show();
}
private void getJSON(final String urlWebService) {
class GetJSON extends AsyncTask<Void, Void, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
try {
loadIntoListView(s);
} catch (JSONException e) {
e.printStackTrace();
}
}
@Override
protected String doInBackground(Void... voids) {
try {
URL url = new URL(urlWebService);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
StringBuilder sb = new StringBuilder();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));
String json;
while ((json = bufferedReader.readLine()) != null) {
sb.append(json + "\n");
}
return sb.toString().trim();
} catch (Exception e) {
return null;
}
}
}
GetJSON getJSON = new GetJSON();
getJSON.execute();
}
}
我不确定是否有任何错误消息,但我认为视图绑定很奇怪。请检查以下代码。从
rootView
中查找listView
,因为您的listView
可以为空
public class Bamanual extends Fragment {
ListView listView;
ArrayList<HashMap<String, String>> list_data;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_bamanual, container, false);
listView = (ListView) rootView.findViewById(R.id.listView1);
return rootView;
}
也请出示你的日志。@Kimkvin请检查我更新的邮件我猜是对的。请检查我的答案。可能是重复的谢谢你,太多了。它解决了我的问题。如果您选中此部分
String name=obj.getString(“ItemCode”);String photo=obj.getString(“PhotoName”);项目。添加(名称)代码>。我想两个都发送,我怎么能做到呢?@YVS1102创建模型对象SomethingPhoto
,它有字符串代码和字符串名称,你只能使用这样的列表。我不知道,我想我会使用谷歌。thanks@YVS1102您需要将ArrayAdapter更改为ArrayAdapter。谢谢你:祝你今天愉快!
12-12 09:59:21.382 14806-15139/com.example.boby.firstapp E/StudioProfiler: JVMTI error: 15(JVMTI_ERROR_THREAD_NOT_ALIVE)
12-12 09:59:21.388 14806-15139/com.example.boby.firstapp E/StudioProfiler: JVMTI error: 15(JVMTI_ERROR_THREAD_NOT_ALIVE)
12-12 09:59:30.235 14806-14806/com.example.boby.firstapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.boby.firstapp, PID: 14806
java.lang.NullPointerException: Attempt to invoke virtual method 'android.view.View android.widget.ListView.findViewById(int)' on a null object reference
at com.example.boby.firstapp.Bamanual.loadIntoListView(Bamanual.java:55)
at com.example.boby.firstapp.Bamanual.access$000(Bamanual.java:25)
at com.example.boby.firstapp.Bamanual$1GetJSON.onPostExecute(Bamanual.java:73)
at com.example.boby.firstapp.Bamanual$1GetJSON.onPostExecute(Bamanual.java:62)
at android.os.AsyncTask.finish(AsyncTask.java:695)
at android.os.AsyncTask.-wrap1(Unknown Source:0)
at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:712)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
public class Bamanual extends Fragment {
ListView listView;
ArrayList<HashMap<String, String>> list_data;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_bamanual, container, false);
listView = (ListView) rootView.findViewById(R.id.listView1);
return rootView;
}
public class Bamanual extends Fragment {
ListView listView;
ArrayList<Photo> list_data;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_bamanual, container, false);
listView = (ListView) rootView.findViewById(R.id.listView1);
return rootView;
}
@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
getActivity().setTitle("Menu Ba Manual");
getJSON("http://192.168.3.223:84/fppb/andro_login/fppb");
}
private void loadIntoListView(String json) throws JSONException {
List<Photo> items = new ArrayList<Photo>();
JSONArray jsonArray = new JSONArray(json);
String[] ba = new String[jsonArray.length()];
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject obj = jsonArray.getJSONObject(i);
String code=obj.getString("ItemCode");
String name=obj.getString("PhotoName");
items.add(new Photo(code, name);
}
ArrayAdapter<Photo> mArrayAdapter = new ArrayAdapter<Photo>(getActivity(),android.R.layout.simple_expandable_list_item_1, items);
listView.setAdapter(mArrayAdapter);
//Toast.makeText(getActivity(), jsonArray.toString(), Toast.LENGTH_LONG).show();
}
public class Photo {
String code;
String name;
public Photo(String code, String name) {
this.code = code;
this.name = name;
}
public String getCode() {
return code;
}
public String getName() {
return name;
}
}