1
我很新的Android編程，所以任何幫助將是偉大的:) 我試圖得到一些虛擬數據遠程，解析JSON響應並顯示它在一個列表視圖。Android Asynctask HTTP在ListView中不顯示結果？
這是XML佈局文件我試圖與該列表活動使用方法： -
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<ListView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/list"
/>
</LinearLayout>
這是我的http搜索活動： -
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.net.ParseException;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
public class searchResultActivity extends ListActivity {
ListView listview;
String result = null;
InputStream is = null;
StringBuilder sb = null;
String url;
String fd_name;
ArrayList<String> listItems;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
/*setContentView(R.layout.test);
listview = (ListView)findViewById(R.id.list);*/
url = "http://pjchambers.comuf.com/index.php";
new getData().execute();
}
public class getData extends AsyncTask<String, Void, ArrayList<String>> {
protected ArrayList<String> doInBackground(String...urls) {
// TODO Auto-generated method stub
listItems = new ArrayList<String>();
try {
// Set of http statements setting up the connections to the php
// and database
HttpClient httpclient = new DefaultHttpClient();
HttpGet httpget = new HttpGet(url);
HttpResponse response = httpclient.execute(httpget);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection" + e.toString());
}
// convert response to string
try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(is, "iso-8859-1"), 8);
sb = new StringBuilder();
sb.append(reader.readLine() + "\n");
String line = "0";
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}
// paring data
try {
JSONArray jArray = new JSONArray(result);
JSONObject json_data = null;
for (int i = 0; i < jArray.length(); i++) {
json_data = jArray.getJSONObject(i);
fd_name = json_data.getString("Name");
listItems.add(fd_name);
}
} catch (JSONException e1) {
Toast.makeText(getBaseContext(), "No Results Found",
Toast.LENGTH_LONG).show();
} catch (ParseException e1) {
e1.printStackTrace();
}
Log.d("debug", "- " + listItems.toString());
return listItems;
}
protected void doPostExecute() {
ArrayAdapter<String> adapter = new ArrayAdapter<String>(
searchResultActivity.this, android.R.layout.simple_list_item_1, R.id.list, listItems);
setListAdapter(adapter);
}
}
}
我花了幾個小時試圖不同的方法和方法，使用一些不同的在線教程，但它們都以相同的結果結束。由於它的應用程序有效，但顯示屏幕顯示;但是，如果我在onCreate方法中聲明佈局應用程序崩潰。任何幫助或建議將必須意識到，一套新的眼睛可能會注意到的問題（一個或多個）直線距離
這是logcat的後，我註釋掉的兩個語句
05-22 12:12:20.234: D/debug(631): - [The Arena, Empire]
05-22 12:12:42.004: I/dalvikvm(691): threadid=3: reacting to signal 3
05-22 12:12:42.244: I/dalvikvm(691): Wrote stack traces to '/data/anr/traces.txt'
05-22 12:12:42.404: D/gralloc_goldfish(691): Emulator without GPU emulation detected.
05-22 12:12:48.415: I/dalvikvm(691): threadid=3: reacting to signal 3
05-22 12:12:48.424: I/dalvikvm(691): Wrote stack traces to '/data/anr/traces.txt'
05-22 12:12:50.595: D/AndroidRuntime(691): Shutting down VM
05-22 12:12:50.595: W/dalvikvm(691): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
05-22 12:12:50.614: E/AndroidRuntime(691): FATAL EXCEPTION: main
05-22 12:12:50.614: E/AndroidRuntime(691): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.project.barcrawl/com.project.barcrawl.searchResultActivity}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1956)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.ActivityThread.access$600(ActivityThread.java:123)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.os.Handler.dispatchMessage(Handler.java:99)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.os.Looper.loop(Looper.java:137)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.ActivityThread.main(ActivityThread.java:4424)
05-22 12:12:50.614: E/AndroidRuntime(691): at java.lang.reflect.Method.invokeNative(Native Method)
05-22 12:12:50.614: E/AndroidRuntime(691): at java.lang.reflect.Method.invoke(Method.java:511)
05-22 12:12:50.614: E/AndroidRuntime(691): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
05-22 12:12:50.614: E/AndroidRuntime(691): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
05-22 12:12:50.614: E/AndroidRuntime(691): at dalvik.system.NativeStart.main(Native Method)
05-22 12:12:50.614: E/AndroidRuntime(691): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.ListActivity.onContentChanged(ListActivity.java:243)
05-22 12:12:50.614: E/AndroidRuntime(691): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:254)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.Activity.setContentView(Activity.java:1835)
05-22 12:12:50.614: E/AndroidRuntime(691): at com.project.barcrawl.searchResultActivity.onCreate(searchResultActivity.java:41)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.Activity.performCreate(Activity.java:4465)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
05-22 12:12:50.614: E/AndroidRuntime(691): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1920)
05-22 12:12:50.614: E/AndroidRuntime(691): ... 11 more
05-22 12:12:51.004: I/dalvikvm(691): threadid=3: reacting to signal 3
05-22 12:12:51.024: I/dalvikvm(691): Wrote stack traces to '/data/anr/traces.txt'
你是什麼意思「如果我聲明佈局」？你的意思是2條評論線？你能詳細說明你的實際問題和疑問嗎？並添加錯誤日誌。謝謝！ – Joe
您需要首先取消註釋這兩行才能使其工作。基於logcat的 –
究竟是哪裏的問題？你能連接到互聯網嗎？你解析成功了嗎？ – Hesam