如何在不使用自定義適配器的情況下將子項目添加到列表視圖

Question

在我的列表視圖中，我正在使用某些數據gettinng可用wi-fi的列表，我想要的是將數組項目[0]顯示爲項目和數組項目[2]作爲一個子項目，而不使用自定義適配器和消耗性列表視圖

這裏是我將數據添加到列表視圖中的代碼。

import java.util.List; 

import android.net.wifi.ScanResult; 
import android.net.wifi.WifiManager; 
import android.os.Bundle; 
import android.annotation.SuppressLint; 
import android.app.Activity; 
import android.content.BroadcastReceiver; 
import android.content.Context; 
import android.content.Intent; 
import android.content.IntentFilter; 
import android.view.Menu; 
import android.widget.ArrayAdapter; 
import android.widget.ExpandableListView; 
import android.widget.ListView; 

public class MainActivity extends Activity { 
     WifiManager mainWifiObj; 
     WifiScanReceiver wifiReciever; 
     ExpandableListView list; 
     String wifis[]; 


    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     list = (ExpandableListView)findViewById(R.id.ListView1); 
      mainWifiObj = (WifiManager) getSystemService(Context.WIFI_SERVICE); 
      wifiReciever = new WifiScanReceiver(); 
      mainWifiObj.startScan(); 

    } 
     protected void onPause() { 
       unregisterReceiver(wifiReciever); 
       super.onPause(); 
      } 

     protected void onResume() { 
       registerReceiver(wifiReciever, new IntentFilter(
       WifiManager.SCAN_RESULTS_AVAILABLE_ACTION)); 
       super.onResume(); 
      } 
     class WifiScanReceiver extends BroadcastReceiver { 
       @SuppressLint("UseValueOf") 
       public void onReceive(Context c, Intent intent) { 
       List<ScanResult> wifiScanList = mainWifiObj.getScanResults(); 
       wifis = new String[wifiScanList.size()]; 
       for(int i = 0; i < wifiScanList.size(); i++){ 
        wifis[i] = ((wifiScanList.get(i)).toString()); 
       } 
       String filtered[] = new String[wifiScanList.size()]; 
        int counter = 0; 
        for (String eachWifi : wifis) { 
         String[] temp = eachWifi.split(","); 

         filtered[counter] = temp[0].substring(5).trim()+"\n" + temp[2].substring(12).trim()+"\n" +temp[3].substring(6).trim();//0->SSID, 2->Key Management 3-> Strength 


         counter++; 

        } 
        list.setAdapter(new ArrayAdapter<String>(getApplicationContext(), 
          android.R.layout.simple_list_item_1, filtered)); 


       } 
      } 
} 

Answer 1

您可以通過僅使用自定義適配器來實現此目的。下面是我轉換您的問題從我爲我的列表視圖中創建一個自定義適配器的例子：

import java.util.ArrayList; 
import android.annotation.SuppressLint; 
import android.app.Activity; 
import android.content.Intent; 
import android.graphics.drawable.Drawable; 
import android.net.Uri; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.view.ViewGroup; 
import android.widget.BaseAdapter; 
import android.widget.Button; 
import android.widget.ImageView; 
import android.widget.LinearLayout; 
import android.widget.TextView; 

public class CustomListAdapter extends BaseAdapter { 

    private static final int TYPE_ITEM = 0; 

    private static final int TYPE_SUBITEM = 1; 

    private static final int TYPE_MAX_COUNT = TYPE_SUBITEM + 1; 

    private ArrayList<String> listViewItems; 

    public LayoutInflater mInflater; 

    public CustomListAdapter(Activity act){ 
     this.listViewItems= new listViewItems<String>(); 
     mInflater = (LayoutInflater) act.getApplicationContext().getSystemService(Activity.LAYOUT_INFLATER_SERVICE); 
    } 

    @SuppressLint("InflateParams") 
    @Override 
    public View getView(final int position, View convertView, ViewGroup parent) { 
     //this finds out the type of the view that is being created 
     int type = getItemViewType(position); 

     switch (type) { 
      case TYPE_ITEM: 
       if(convertView == null) 
        convertView = mInflater.inflate(R.layout.listview_item, null); 
       //the following is an example to change things in subitem 
       TextView text_of_item = (TextView) convertView.findViewById(R.id.textView_item); 
       text_of_item.setText("item"+position); 
       break; 

      case TYPE_SUBITEM: 
       if(convertView == null) 
        convertView = mInflater.inflate(R.layout.listview_subitem, null); 
       //the following is an example to change things in subitem 
       TextView text_of_subitem = (TextView) convertView.findViewById(R.id.textView_subitem); 
       text_of_subitem.setText("subitem"+position); 
       break; 
     } 

     return convertView; 
    } 

    @Override 
    public int getItemViewType(int position) { 
      //you can achive this part via using integer IDs. Just change your ArrayList<String> to ArrayList<int> 

     if(listViewItems.get(position).equals("item")){//I suppose you give unique names to your subitems 
      return TYPE_ITEM; 
     }else if(listViewItems.get(position).equals("subitem")){//I suppose you give unique names to your subitems 
      return TYPE_SUBITEM; 
    } 

    @Override 
    public int getViewTypeCount() { 
     return TYPE_MAX_COUNT; 
    } 


    @Override 
    public int getCount() { 
     return listViewItems.size(); 
    } 

    @Override 
    public String getItem(int position) {  
     return listViewItems.get(position); 
    } 

    @Override 
    public long getItemId(int position) { 
     return position; 
    } 

    public void addItem(String item){ 
     listViewItems.add(item); 
     notifyDataSetChanged(); 
    } 

    public void removeItem(int position){ 
     listViewItems.remove(position); 
     notifyDataSetChanged(); 
    } 

} 

，你應該從你的MainActivity如下稱之爲：

CustomListAdapter mCustomListAdapter = new CustomListAdapter (this); 

ListView mList = (ListView) findViewById(R.id.listview); 
mList.setAdapter(mCustomListAdapter); 

//when you want to add item to your listview just add the following: 
mCustomListAdapter.addItem("item"); 

//when you want to add subitem to your listview just add the following: 
mCustomListAdapter.addItem("subitem"); 

還您listview_subitem。 XML可以是這樣的：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/list_subitem" 
    android:layout_width="match_parent" 
    android:layout_height="50dp" 
    android:orientation="horizontal" > 

    <TextView 
    android:id="@+id/textView_subitem" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="TextView" /> 

</LinearLayout> 

和你listview_item.xml可以這樣：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/list_item" 
    android:layout_width="match_parent" 
    android:layout_height="48dp" 
    android:orientation="horizontal" > 

    <TextView 
    android:id="@+id/textView_item" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="TextView" /> 
</LinearLayout> 

您activity_main.xml中：

<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android" 
    android:id="@+id/linear_layout" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent"> 

    <!-- Listview to display slider menu --> 
    <ListView 
     android:id="@+id/listview" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent"/> 
</LinearLayout>