Question

我有一个包含键值对的自定义BaseAdapter。在我的ListView中，当我点击列表中的某个项目时，我想将其从列表中删除。我的问题是我不知道如何执行notifyDataSetChanged - 请参阅下面的onListItemClick。

我在MyCustomAdapter中有一个导致疼痛的构造函数。

下面的代码是两个类。

第1课

Dynamiclists extends ListActivity

第2课

MyCustomAdapter extends BaseAdapter

在第1课中，我想从HashMap指示的位置移除onListItemClick地图，然后更新第2课。

package telephone.org;


import java.util.HashMap;
import java.util.Set;
import java.util.Map.Entry;

import telephone.org.MyService.LocalBinder;
import android.app.ActivityManager;
import android.app.ListActivity;
import android.app.ActivityManager.RunningServiceInfo;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.os.IBinder;
import android.provider.ContactsContract;
import android.provider.ContactsContract.PhoneLookup;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemLongClickListener;


//class 1 
public class DynamicLists extends ListActivity { 


    MyService mService;
    boolean mBound = false;


//class 2 ///////////////////////////////////
public class MyCustomAdapter extends BaseAdapter { 


    public HashMap<String, Integer> mData = new HashMap<String,Integer>();
    private String[] mKeys;
    //constructor    
    public MyCustomAdapter(DynamicLists dynamicLists, int row, HashMap<String, Integer> map){ 
    mData = map;
    mKeys = mData.keySet().toArray(new String[map.size()]);
    Log.d(TAG, "INSIDE ADAPTER constructor HELLO WORLD " + map.entrySet()); 

}

public MyCustomAdapter(MyService mService, int row, Object map) {
        // TODO Auto-generated constructor stub
    }

@Override
public View getView(int position, View convertView, ViewGroup parent) {
//TODO Auto-generated method stub

    Log.d(TAG, "inside getview  ");
  View row=convertView;

if (row==null){
    LayoutInflater inflater=getLayoutInflater();
    row=inflater.inflate(R.layout.row, null);
}

TextView label =(TextView)row.findViewById(R.id.blocked);
label.setText(mKeys[position] +  "   " + getItem(position).toString()); //key + value 
return row;   


}



@Override
public int getCount() 
{
    // TODO Auto-generated method stub
    return mData.size();
}
@Override
public Object getItem(int position) 
{
    // TODO Auto-generated method stub
    Log.d(TAG, "inside getitem " + mData.get(mKeys[position])); 
    return mData.get(mKeys[position]);
}
@Override
public long getItemId(int position) 
{
    // TODO Auto-generated method stub
    return position;
}

}  //end of class 2 ////////////////////////



private static final String TAG = "DynamicList";

//class 1 

public static  HashMap<String, Integer> map = new HashMap<String, Integer>(); 

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);


}


@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
//TODO Auto-generated method stub

//remove entries from hashmap map   
String selection = l.getItemAtPosition(position).toString();
String[] tkeys;
tkeys = map.keySet().toArray(new String[map.size()]);
Integer toremove = map.get(tkeys[position]);
Toast.makeText(this, "The value is" + map.get(tkeys[position]), Toast.LENGTH_LONG).show();
map.remove(toremove);
//how to notify MyCustomAdapter of changes 

//end of remove entries from hashmap map  
}

@Override
public void onStart() {
    super.onStart();
     isMyServiceRunning();

}


public void onStop() {
    super.onStop();
    // Unbind from the service
    if (mBound) {
    unbindService(mConnection);
    mBound = false;
    }
}

private boolean isMyServiceRunning() { 
    ActivityManager manager = (ActivityManager) getSystemService(ACTIVITY_SERVICE); 
    for (RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) { 
        if ("telephone.org.MyService".equals(service.service.getClassName())) 
        { 
            Toast.makeText(getApplicationContext(),"SERVICE IS RUNNING", Toast.LENGTH_LONG).show();
            Intent intent = new Intent(this, MyService.class);
            bindService(intent, mConnection, Context.BIND_AUTO_CREATE);  //SEE INTERACT WITH SERVICE BELOW


            return true; 
        } 
    } 
           Toast.makeText(getApplicationContext(),"SERVICE IS STOPPED AND IS NOT RUNNING", Toast.LENGTH_LONG).show();
    return false; 
} 

//INTERACT WITH SERVICE
/** Defines callbacks for service binding, passed to bindService() */
private ServiceConnection mConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName className, IBinder service) {
// We've bound to LocalService, cast the IBinder and get LocalService instance
LocalBinder binder = (LocalBinder) service;
mService = binder.getService();
mBound = true;
Set<Entry<String, Integer>> whatsup = mService.getNumbers();
Toast.makeText(getApplicationContext(),"NUMBER INTERACTION IS" + whatsup, Toast.LENGTH_LONG).show();
Log.d(TAG, "ELEMENTS from service are:" + whatsup);
Toast.makeText(getApplicationContext(),"NUMBER OF ENTRIES IS" + whatsup.size(), Toast.LENGTH_LONG).show();


//convert SET BACK TO HASHMAP 
for (Entry<String,Integer> entry : whatsup) { 

    String name = null; 
    String[] projection = new String[] { 
            ContactsContract.PhoneLookup.DISPLAY_NAME};
    Uri uri = Uri.withAppendedPath(PhoneLookup.CONTENT_FILTER_URI, Uri.encode(entry.getKey())); 
    Cursor cursor = getContentResolver().query(uri, projection, null, null, null);

    if (cursor.moveToFirst()) { 
        name = cursor.getString(cursor.getColumnIndex(ContactsContract.PhoneLookup.DISPLAY_NAME));
    }
    Toast.makeText(getApplicationContext(),"RESOLVED NAME IS " + name, Toast.LENGTH_LONG).show();
    projection = null;
    map.put(name,entry.getValue()); 
    }


setListAdapter(new MyCustomAdapter(DynamicLists.this, R.layout.row, map));

}

//end CONVERT SET BACK TO HASHMAP


@Override
public void onServiceDisconnected(ComponentName arg0) {
mBound = false;
}
};
//END INTERACTION WITH SERVICE 

} //end of class 1

Answer 1

我在缩进时有点麻烦，但是你确认你的onListItemClick函数删除了正确的HashMap /行吗？如果是这样，那么在onListItemClick调用结束时：

getListAdapter().notifyDataSetChanged();

但是，我不喜欢您使用position的方式，例如tkeys[position]。 Position是可见项的索引，id是所有项的索引。但是，如果它有效，那么我没有抱怨。

我没有对此进行过测试，但它应该作为一种替代方法（假设map是构建ListView的集合：

public void onListItemClick(ListView l, View v, int position, long id) {
    MyCustomAdapter adapter = getListAdapter();
    map.remove(adapter.get((int) id));
    adapter.notifyDataSetChanged();
}

无法从onListItemClick（）上的自定义BaseAdapter中删除项目

1 个答案: