在平板电脑上的ListView

Question

我有一个代码，从数据库中回顾并显示结果在listView ..当我试图复制代码并将其粘贴到另一个项目，这是平板电脑应用程序它没有工作！为什么？有人可以告诉我吗？

这里是我的java类

public class EditExs extends ListActivity { 

// Progress Dialog 
private ProgressDialog pDialog; 

// Creating JSON Parser object 
JSONParser jParser = new JSONParser(); 

ArrayList<HashMap<String, String>> productsList; 

// url to get all products list 
private static String url_all_products = "http://www.lamia.byethost18.com/get_all_ex.php"; 

// JSON Node names 
private static final String TAG_SUCCESS = "success"; 
private static final String TAG_PRODUCTS = "products"; 
private static final String TAG_PID = "ID_exercise"; 
private static final String TAG_NAME = "ID_exercise"; 

// products JSONArray 
JSONArray products = null; 

public String cha,lev; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_edit_exs); 

    Intent i = getIntent(); 
    cha = i.getStringExtra("chapter"); 
    lev = i.getStringExtra("level"); 

     Log.d(null, cha); 
     Log.d(null, lev); 
    // Hashmap for ListView 
    productsList = new ArrayList<HashMap<String, String>>(); 

    // Loading products in Background Thread 
    new LoadAllProducts().execute(); 

    // Get listview 
    ListView lv = getListView(); 

    // on seleting single product 
    // launching Edit Product Screen 
    lv.setOnItemClickListener(new OnItemClickListener() { 

     @Override 
     public void onItemClick(AdapterView<?> parent, View view, 
       int position, long id) { 


      // getting values from selected ListItem 
      TextView t=(TextView) view.findViewById(R.id.pid); 
      String pid =t.getText().toString(); 
      Intent in = new Intent(getApplicationContext(), EditEx.class); 
      in.putExtra("ID", pid); 
      startActivity(in); 
     /* // Starting new intent 
      Intent in = new Intent(getApplicationContext(), 
        EditProductActivity.class); 
      // sending pid to next activity 

      // starting new activity and expecting some response back 
      startActivityForResult(in, 100);*/ 
     } 
    }); 

} 

// Response from Edit Product Activity 
@Override 
protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 
    // if result code 100 
    if (resultCode == 100) { 
     // if result code 100 is received 
     // means user edited/deleted product 
     // reload this screen again 
     Intent intent = getIntent(); 
     finish(); 
     startActivity(intent); 
    } 

} 

/** 
* Background Async Task to Load all product by making HTTP Request 
* */ 
class LoadAllProducts extends AsyncTask<String, String, String> { 

    /** 
    * Before starting background thread Show Progress Dialog 
    * */ 
    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
     pDialog = new ProgressDialog(EditExs.this); 
     pDialog.setMessage("Loading products. Please wait..."); 
     pDialog.setIndeterminate(false); 
     pDialog.setCancelable(false); 
     pDialog.show(); 
    } 

    /** 
    * getting All products from url 
    * */ 
    protected String doInBackground(String... args) { 
     String l=lev; 
     String ch=cha; 

     // Building Parameters 
     List<NameValuePair> params = new ArrayList<NameValuePair>(); 
     //params.add(new BasicNameValuePair("ID_chapter", ch)); 
     //params.add(new BasicNameValuePair("level", l)); 

     // getting JSON string from URL 
     JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params); 

     // Check your log cat for JSON reponse 
     Log.d("All Products: ", json.toString()); 

     try { 
      // Checking for SUCCESS TAG 
      int success = json.getInt(TAG_SUCCESS); 

      if (success == 1) { 
       // products found 
       // Getting Array of Products 
       products = json.getJSONArray(TAG_PRODUCTS); 

       // looping through All Products 
       for (int i = 0; i < products.length(); i++) { 
        JSONObject c = products.getJSONObject(i); 

        // Storing each json item in variable 
        String id = c.getString(TAG_PID); 
        String name = c.getString(TAG_NAME); 

        // creating new HashMap 
        HashMap<String, String> map = new HashMap<String, String>(); 

        // adding each child node to HashMap key => value 
        map.put(TAG_PID, id); 
        map.put(TAG_NAME, name); 

        // adding HashList to ArrayList 
        productsList.add(map); 
       } 
      } else { 
       // no products found 
       // Launch Add New product Activity 
       Intent i = new Intent(getApplicationContext(), 
         NewProductActivity.class); 
       // Closing all previous activities 
       i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
       startActivity(i); 
      } 
     } catch (JSONException e) { 
      e.printStackTrace(); 
     } 

     return null; 
    } 

    /** 
    * After completing background task Dismiss the progress dialog 
    * **/ 
    protected void onPostExecute(String file_url) { 
     // dismiss the dialog after getting all products 
     pDialog.dismiss(); 
     // updating UI from Background Thread 
     runOnUiThread(new Runnable() { 
      public void run() { 
       /** 
       * Updating parsed JSON data into ListView 
       * */ 
       ListAdapter adapter = new SimpleAdapter(
         EditExs.this, productsList, 
         R.layout.item_list_3, new String[] {TAG_NAME}, 
         new int[] { R.id.pid}); 
       // updating listview 
       setListAdapter(adapter); 
      } 
     }); 

    } 

} 
} 

activity_edit_exs.xml

<RelativeLayout 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" 
android:paddingBottom="@dimen/activity_vertical_margin" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
tools:context=".ViewExs" > 

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

</RelativeLayout> 

item_list_3.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:layout_width="fill_parent" 
android:layout_height="wrap_content" 
android:orientation="vertical" > 

<TextView 
    android:id="@+id/pid" 
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:visibility="visible" /> 


</RelativeLayout> 

我得到的错误是：

10-01 02:02:28.333: E/AndroidRuntime(923): FATAL EXCEPTION: main 
10-01 02:02:28.333: E/AndroidRuntime(923): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.anistat/com.example.anistat.AdminEditExs}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list' 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2211) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.ActivityThread.access$600(ActivityThread.java:141) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.os.Handler.dispatchMessage(Handler.java:99) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.os.Looper.loop(Looper.java:137) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.ActivityThread.main(ActivityThread.java:5103) 
10-01 02:02:28.333: E/AndroidRuntime(923): at java.lang.reflect.Method.invokeNative(Native Method) 
10-01 02:02:28.333: E/AndroidRuntime(923): at java.lang.reflect.Method.invoke(Method.java:525) 
10-01 02:02:28.333: E/AndroidRuntime(923): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
10-01 02:02:28.333: E/AndroidRuntime(923): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
10-01 02:02:28.333: E/AndroidRuntime(923): at dalvik.system.NativeStart.main(Native Method) 
10-01 02:02:28.333: E/AndroidRuntime(923): Caused by: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list' 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.ListActivity.onContentChanged(ListActivity.java:243) 
10-01 02:02:28.333: E/AndroidRuntime(923): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:270) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.Activity.setContentView(Activity.java:1895) 
10-01 02:02:28.333: E/AndroidRuntime(923): at com.example.anistat.AdminEditExs.onCreate(AdminEditExs.java:56) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.Activity.performCreate(Activity.java:5133) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
10-01 02:02:28.333: E/AndroidRuntime(923): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175) 
10-01 02:02:28.333: E/AndroidRuntime(923): ... 11 more 

也试图此行

ListView lv = getListView(); 

改变这种

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

，但它没有工作

我也试图与值的简单列表视图，当我运行它之间有一个巨大的空间项目如何解决它？

我想知道手机和平板电脑的实施是否有区别？

有人可以帮我吗？谢谢。

Answer 1

好的我认为问题是在您的xml文件中声明的上下文中。

只是改变tools:context=".ViewExs"到tools:context=".EditExs"

检查它。 多数民众赞成在它..