強制關閉的ListView在Android的

Question

，當我跑我的模擬器，它只是強制關閉這裏是logcat的節目......

07-16 03:12:30.536: D/AndroidRuntime(386): Shutting down VM 
07-16 03:12:30.536: W/dalvikvm(386): threadid=1: thread exiting with uncaught exception    (group=0x4001d800) 
07-16 03:12:30.556: E/AndroidRuntime(386): FATAL EXCEPTION: main 
07-16 03:12:30.556: E/AndroidRuntime(386): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.database_demo/com.database_demo.Database_demo}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list' 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.os.Handler.dispatchMessage(Handler.java:99) 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.os.Looper.loop(Looper.java:123) 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.app.ActivityThread.main(ActivityThread.java:4627) 
07-16 03:12:30.556: E/AndroidRuntime(386): at java.lang.reflect.Method.invokeNative(Native Method) 
07-16 03:12:30.556: E/AndroidRuntime(386): at java.lang.reflect.Method.invoke(Method.java:521) 
07-16 03:12:30.556: E/AndroidRuntime(386): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
07-16 03:12:30.556: E/AndroidRuntime(386): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
07-16 03:12:30.556: E/AndroidRuntime(386): at dalvik.system.NativeStart.main(Native Method) 
07-16 03:12:30.556: E/AndroidRuntime(386): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list' 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.app.ListActivity.onContentChanged(ListActivity.java:245) 
07-16 03:12:30.556: E/AndroidRuntime(386): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:201) 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.app.Activity.setContentView(Activity.java:1647) 
07-16 03:12:30.556: E/AndroidRuntime(386): at com.database_demo.Database_demo.onCreate(Database_demo.java:40) 
07-16 03:12:30.556: E/AndroidRuntime(386): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
07-16 03:12:30.556: E/AndroidRuntime(386): at   android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 
07-16 03:12:30.556: E/AndroidRuntime(386): ... 11 more 

我的Java代碼

package com.database_demo; 

import java.io.BufferedReader; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.util.ArrayList; 
import java.util.List; 

import org.apache.http.HttpEntity; 
import org.apache.http.HttpResponse; 
import org.apache.http.NameValuePair; 
import org.apache.http.client.HttpClient; 
import org.apache.http.client.entity.UrlEncodedFormEntity; 
import org.apache.http.client.methods.HttpPost; 
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.Bundle; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 
import android.widget.Toast; 

public class Database_demo extends ListActivity { 
ListView list; 
List<String> items = new ArrayList<String>(); 
String result = null; 
InputStream is = null;; 
StringBuilder sb = null; 
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); 
/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 

    setContentView(R.layout.main); 

    list = (ListView)findViewById(R.id.listView1); 



    items.add("Employ"); 

    try{ 

    //http post 
    HttpClient httpclient = new DefaultHttpClient(); 
    HttpPost httppost = new HttpPost("http://192.168.0.2/ListView/wa.php"); 
    List<NameValuePair> nameValue=new ArrayList<NameValuePair>(); 
    httppost.setEntity(new UrlEncodedFormEntity(nameValue)); 
    HttpResponse response = httpclient.execute(httppost); 
    HttpEntity entity = response.getEntity(); 
    is = entity.getContent(); 
    } 
    catch(Exception e){ 
     Toast.makeText(getBaseContext(),e.toString() ,Toast.LENGTH_LONG).show(); 
    } 

    //Convert response to string 
    try 
    { 
     BufferedReader reader = new BufferedReader(new InputStreamReader(is,"UTF-8")); 

     sb = new StringBuilder(); 

     String line = null; 

     while ((line = reader.readLine()) != null) 
     { 
     sb.append(line + "\n"); 
     } 

     is.close(); 

     result = sb.toString(); 
    } 
    catch(Exception e) 
    { 
     Toast.makeText(getBaseContext(),e.toString() ,Toast.LENGTH_LONG).show(); 
    } 
    //END Convert response to string 
    String Cat; 
    try{ 
      JSONArray jArray = new JSONArray(result); 
      JSONObject json_data=null; 
      for(int i=0;i<jArray.length();i++) 
      { 
       json_data = jArray.getJSONObject(i); 
       Cat=json_data.getString("category"); 
       items.add("Category: " + Cat); 
      } 
     setupList(); 
     } 
     catch(JSONException e1){ 
      Toast.makeText(getBaseContext(),e1.toString() ,Toast.LENGTH_LONG).show(); 
     } catch (ParseException e1) { 
      Toast.makeText(getBaseContext(),e1.toString() ,Toast.LENGTH_LONG).show(); 
    } 

} 
private void setupList(){ 
    list.setAdapter(new ArrayAdapter<String>(this, 
      android.R.layout.simple_list_item_1, items)); 
} 
} 

你能幫助我這個？

Answer 1

產生的原因：了java.lang.RuntimeException：您的內容必須有一個 的ListView其id屬性爲 'android.R.id.list'

<ListView 
android:id="@android:id/list" // must be there is xml 

http://developer.android.com/reference/android/app/ListActivity.html

ListActivity有一個默認佈局，其中包含屏幕中央的單個全屏列表。但是，如果您願意，您可以通過onCreate()中的setContentView()設置您自己的視圖佈局來自定義屏幕布局。要做到這一點，自己的觀點必須包含id爲「@android:id/list」（或列表，如果它在代碼）

Answer 2

你是在擴展ListActivity一個ListView對象。這意味着，佈局main.xml中必須包含與Android的ListView：ID = 「@機器人：ID /列表」

Answer 3

您需要使用列表視圖

<ListView android:id="@android:id/list" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"/> 

的XML由於您使用ListActivity你的XML文件必須在提及ID時指定關鍵字android。

如果你需要一個自定義的ListView，那麼不必擴展一個ListActivity，你只需要擴展一個Activity並且應該有沒有關鍵字android的相同id。

Answer 4

改變這一行：

list = (ListView)findViewById(R.id.listView1); 

到

list = getListView(); 

//或寫

ListView list = (ListView)findViewById(android.R.id.list); 

，並在您佈局XML爲ListView ID使用

android:id="@android:id/list"