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如何从android的listview中选择一个特定的项目？

2013-03-20 79 views
-1

我有一个list-view.It包含了一些来自Web服务的数据。如何从android的listview中选择一个特定的项目？

这里我需要的是，如果我点击该列表视图中的任何项目，它想显示来自Web服务的数据。 我是否可以为此编写任何循环代码？ 如何做到这一点？

logcat的

03-20 13:09:07.187: W/KeyCharacterMap(275): No keyboard for id 0 
03-20 13:09:07.187: W/KeyCharacterMap(275): Using default keymap: /system/usr/keychars/qwerty.kcm.bin 
03-20 13:09:13.116: I/System.out(275): Transparent 17170445 
03-20 13:09:13.136: W/System.err(275): org.json.JSONException: Value Login of type java.lang.String cannot be converted to JSONArray 
03-20 13:09:13.136: W/System.err(275): at org.json.JSON.typeMismatch(JSON.java:107) 
03-20 13:09:13.136: W/System.err(275): at org.json.JSONArray.<init>(JSONArray.java:91) 
03-20 13:09:13.136: W/System.err(275): at org.json.JSONArray.<init>(JSONArray.java:103) 
03-20 13:09:13.136: W/System.err(275): at com.example.png.StationsListActivity.callService(StationsListActivity.java:115) 
03-20 13:09:13.136: W/System.err(275): at com.example.png.StationsListActivity$4.run(StationsListActivity.java:103) 
03-20 13:09:13.196: D/AndroidRuntime(275): Shutting down VM 
03-20 13:09:13.196: W/dalvikvm(275): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 
03-20 13:09:13.206: E/AndroidRuntime(275): FATAL EXCEPTION: main 
03-2 0 13:09:13.206: E/AndroidRuntime(275): java.lang.NullPointerException 
03-20 13:09:13.206: E/AndroidRuntime(275): at com.example.png.StationsListActivity$1.handleMessage(StationsListActivity.java:43) 
03-20 13:09:13.206: E/AndroidRuntime(275): at android.os.Handler.dispatchMessage(Handler.java:99) 
03-20 13:09:13.206: E/AndroidRuntime(275): at android.os.Looper.loop(Looper.java:123) 
03-20 13:09:13.206: E/AndroidRuntime(275): at android.app.ActivityThread.main(ActivityThread.java:4627) 
03-20 13:09:13.206: E/AndroidRuntime(275): at java.lang.reflect.Method.invokeNative(Native Method) 
03-20 13:09:13.206: E/AndroidRuntime(275): at java.lang.reflect.Method.invoke(Method.java:521) 
03-20 13:09:13.206: E/AndroidRuntime(275): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
03-20 13:09:13.206: E/AndroidRuntime(275): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
03-20 13:09:13.206: E/AndroidRuntime(275): at dalvik.system.NativeStart.main(Native Method)

StationsListActivity.java

public class StationsListActivity extends Activity { 

TextView txt; 
String res_data; 

Button btn_info; 
ListView listView; 

ProgressDialog progressDialog; 
List<Stations> list; 

Handler handler =new Handler() 
{ 
    public void handleMessage(android.os.Message msg) 
    { 
     if(progressDialog.isShowing()) 
     { 
     progressDialog.cancel(); 
     if(list.size() > 0) 
     { 
     listView.setAdapter(new StationAdapter(StationsListActivity.this, android.R.id.text1,list));  
     } 
     else 
     { 
     Toast.makeText(StationsListActivity.this, "List is Empty",Toast.LENGTH_LONG).show();  
     } 
     } 
    } 
}; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 
    setContentView(R.layout.stations_list_layout); 

    listView = (ListView)findViewById(R.id.listView_stations); 

    Bundle extras=getIntent().getExtras(); 

    if(extras!=null) 
    { 
     res_data =extras.getString("transfered_data"); 
    } 

    System.out.println("Transparent "+android.R.color.transparent); 
    listView = (ListView) findViewById(R.id.listView_stations); 

    btn_info = (Button)findViewById(R.id.btn_info); 
    progressDialog = new ProgressDialog(StationsListActivity.this); 
    progressDialog.setTitle("Loading"); 
    progressDialog.setMessage("Please Wait"); 
    btn_info.setOnClickListener(new OnClickListener() { 

    @Override 
    public void onClick(View v) { 
     Intent intnt = new Intent(StationsListActivity.this , InformationsActivity.class); 
     startActivity(intnt);   
     } 
    }); 
    Thread thread =new Thread() 
    { 
     @Override 
     public void run() { 
      // TODO Auto-generated method stub 
      callService(); 
      handler.sendEmptyMessage(0); 
     } 
    }; 
    thread.start(); 
    progressDialog.show(); 
} 


public void callService() { 
    // TODO Auto-generated method stub 
    try { 
    JSONArray array = new JSONArray(String.valueOf(res_data).replace("verifyUserResponse{return=", "").replace("; }", "")); 
    list = new ArrayList<Stations>(); 
    for (int i = 0; i < array.length(); i++) 
    { 
     System.out.println(array.getJSONObject(i).get("1")+" == "+array.getJSONObject(i).get("0"));; 
     Stations stations =new Stations(); 
     stations.station_code = (String) array.getJSONObject(i).get("0"); 
     stations.station_name = (String) array.getJSONObject(i).get("1"); 
     list.add(stations); 
     stations = null; 
     } 
    } catch (Exception e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
     } 
    } 
}

StationAdaper.java

public class StationAdapter extends ArrayAdapter<Stations> { 

Context context; 
List<Stations> list; 

public StationAdapter(Context context, int textViewResourceId, 
     List<Stations> objects) { 
    super(context, textViewResourceId, objects); 
    this.context = context ; 
    this.list = objects ; 
    // TODO Auto-generated constructor stub 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
    // TODO Auto-generated method stub 
    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    View view = inflater.inflate(R.layout.station_child, null); 

    TextView name = (TextView) view.findViewById(R.id.textView_single_item); 
    ImageView img = (ImageView)view.findViewById(R.id.imageView1); 

    Stations stations =list.get(position); 
    name.setText(stations.station_name); 
    return view; 

}}

Stations.java 公共类站 {

public String station_name =""; 
public String station_code =""; 


}

station_child.xml

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

<RelativeLayout 

    android:layout_width="fill_parent" 
    android:layout_height="55dp" > 

    <TextView 
     android:id="@+id/textView_single_item" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_marginLeft="10dp" 
     android:layout_alignParentLeft="true" 
     android:layout_centerVertical="true" 
     android:inputType="text" 
     android:textColor="#ffffff" 
     android:textStyle="normal" 
     android:textAppearance="?android:attr/textAppearanceMedium" /> 

    <ImageView 
     android:id="@+id/imageView1" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:layout_alignParentRight="true" 
     android:layout_centerVertical="true" 
     android:layout_marginRight="10dp" 
     android:background="@drawable/arrow"/> 

</RelativeLayout></LinearLayout>

建议请 感谢您的宝贵时间！..

来源

2013-03-20 prabu

+0

请出示您的适配器代码给我们，你的'setOnItemClicked'监听 – Nezam 2013-03-20 07:18:14

+0

你可能想看看http://www.androidhive.info/2011/10/android-listview-tutorial/ – ngesh 2013-03-20 07:19:57

+0

@ Nezam请再次访问我的问题，我已根据您的需求包含我的源代码 – prabu 2013-03-20 07:22:25

回答

1

包括在此代码的OnCreate

// listening to single list item on click 
    listview.setOnItemClickListener(new OnItemClickListener() { 
     public void onItemClick(AdapterView<?> parent, View view, 
      int position, long id) { 

      // selected item 
      String nameOfStation = ((TextView)view.findViewById(R.id.textView_single_item)).getText().toString(); 



     } 
    });

UPDATE logcat的AFTER：

什么你得到一个JSONException已经什么都没有做与你listener.Please变化

JSONArray array = new JSONArray(String.valueOf(res_data).replace("verifyUserResponse{return=", "").replace("; }", ""));

TO

JSONArray array = new JSONArray(res_data);

Inshallah即将解决这个例外。

来源

2013-03-20 07:25:59 Nezam

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