如何使用按钮从listview中删除项目？

Question

List_Remind.xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:padding="5dp" > 

    <TextView 
     android:id="@+id/label" 
     android:layout_width="0dp" 
     android:layout_height="wrap_content" 
     android:text="Hello" 
     android:layout_weight="1" 
     android:textSize="30px" > 
    </TextView> 

    <ImageButton 
     android:background="@null" 
     android:id="@+id/imageButton1" 
     android:layout_width="50px" 
     android:layout_height="50px" 
     android:layout_marginRight="10dp" 
     android:src="@drawable/delete_task" /> 

</LinearLayout> 

ReminderListActivity.java

package com.dummies.android.taskreminder; 

import com.dummies.android.taskreminder.R; 

import android.annotation.SuppressLint; 
import android.app.Activity; 
import android.app.ListActivity; 
import android.content.Context; 
import android.content.Intent; 
import android.database.Cursor; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.ContextMenu; 
import android.view.LayoutInflater; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.ContextMenu.ContextMenuInfo; 
import android.view.View.OnClickListener; 
import android.view.ViewGroup; 
import android.view.Window; 
import android.view.WindowManager; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.CursorAdapter; 
import android.widget.ImageButton; 
import android.widget.LinearLayout; 
import android.widget.ListView; 
import android.widget.SimpleCursorAdapter; 
import android.widget.TextView; 
import android.widget.Toast; 
import android.widget.AdapterView.AdapterContextMenuInfo; 

public class ReminderListActivity extends Activity implements OnClickListener{ 
    private static final int ACTIVITY_CREATE=0; 
    private static final int ACTIVITY_EDIT=1; 

    private RemindersDbAdapter mDbHelper; 
    ListView lvRemind; 
    ImageButton btnAdd,btnBack,btnSettings; 
    TextView text; 
    LinearLayout layout; 
    ArrayAdapterExample aAdapter; 
    int pos; 

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

     requestWindowFeature(Window.FEATURE_NO_TITLE); 
     getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
           WindowManager.LayoutParams.FLAG_FULLSCREEN); 
     // setContentView(R.layout.reminder_list); 
     LayoutInflater inflate = LayoutInflater.from(this); 
     layout = (LinearLayout)inflate.inflate(R.layout.main, null); 
     this.setContentView(layout); 
     btnAdd = (ImageButton) findViewById(R.id.btnAdd); 
     btnBack = (ImageButton) findViewById(R.id.btnBackMain); 
     btnSettings = (ImageButton) findViewById(R.id.btnSettings); 

     btnAdd.setOnClickListener(this); 
     btnBack.setOnClickListener(this); 
     btnSettings.setOnClickListener(this); 
     mDbHelper = new RemindersDbAdapter(this); 
     mDbHelper.open(); 
     fillData(); 

     lvRemind.setOnItemClickListener(new OnItemClickListener() { 

      @Override 
      public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, 
        long arg3) { 
       // TODO Auto-generated method stub 
//    Intent i = new Intent(ReminderListActivity.this, ReminderEditActivity.class); 
//    i.putExtra(RemindersDbAdapter.KEY_ROWID, arg2); 
//   startActivityForResult(i, ACTIVITY_EDIT); 
      // Toast.makeText(ReminderListActivity.this, "Hello", Toast.LENGTH_LONG).show(); 
      } 
     }); 


    } 


    private void fillData() { 
     Cursor remindersCursor = mDbHelper.fetchAllReminders(); 
     startManagingCursor(remindersCursor); 

     // Create an array to specify the fields we want to display in the list (only TITLE) 
     String[] from = new String[]{RemindersDbAdapter.KEY_TITLE}; 

     // and an array of the fields we want to bind those fields to (in this case just text1) 
     int[] to = new int[]{R.id.text1}; 

     // Now create a simple cursor adapter and set it to display 
//  SimpleCursorAdapter reminders = 
//    new SimpleCursorAdapter(this, R.layout.reminder_row, remindersCursor, from, to); 
//  setListAdapter(reminders); 

     text = (TextView)findViewById(R.id.TextView02); 


     lvRemind = (ListView)findViewById(R.id.alist); 

     aAdapter = new ArrayAdapterExample(ReminderListActivity.this, mDbHelper.fetchAllReminders()); 

     lvRemind.setAdapter(aAdapter); 


    } 

    @Override 
    public void onCreateContextMenu(ContextMenu menu, View v, 
      ContextMenuInfo menuInfo) { 
     super.onCreateContextMenu(menu, v, menuInfo); 
     MenuInflater mi = getMenuInflater(); 
     mi.inflate(R.menu.list_menu_item_longpress, menu); 
    } 

    @Override 
    public boolean onContextItemSelected(MenuItem item) { 
     switch(item.getItemId()) { 
     case R.id.menu_delete: 
      AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo(); 
      mDbHelper.deleteReminder(info.id); 
      fillData(); 
      return true; 
     } 
     return super.onContextItemSelected(item); 
    } 

    private void createReminder() { 
     Intent i = new Intent(this, ReminderEditActivity.class); 
     startActivityForResult(i, ACTIVITY_CREATE); 
    } 

// @Override 
// protected void onListItemClick(ListView l, View v, int position, long id) { 
//  super.onListItemClick(l, v, position, id); 
//  Intent i = new Intent(this, ReminderEditActivity.class); 
//  i.putExtra(RemindersDbAdapter.KEY_ROWID, id); 
//  startActivityForResult(i, ACTIVITY_EDIT); 
// } 

    @Override 
    protected void onActivityResult(int requestCode, int resultCode, Intent intent) { 
     super.onActivityResult(requestCode, resultCode, intent); 
     fillData(); 
    } 


    @Override 
    public void onClick(View v) { 
     switch (v.getId()) { 
     case R.id.btnAdd: 
      createReminder(); 
      break; 
     case R.id.btnSettings: 
      Intent i = new Intent(this, TaskPreferences.class); 
      startActivity(i); 
      break; 
     case R.id.btnBackMain: 
      onBackPressed(); 
      break; 
     default: 
      break; 
     } 

    } 

    @SuppressLint("NewApi") 
    @Override 
    public void onBackPressed() { 

     super.onBackPressed(); 
    } 

    class ArrayAdapterExample extends CursorAdapter { 

     public ArrayAdapterExample(Context context, Cursor c) { 

      super(context, c); 

     } 


     @Override 
     public void bindView(View view, Context context, Cursor cursor) { 
      // TODO Auto-generated method stub 
      TextView textViewPersonName = (TextView) view.findViewById(R.id.label); 

       textViewPersonName.setText(cursor.getString(cursor.getColumnIndex(cursor.getColumnName(1)))); 

       Log.d("Index: ", ""+cursor.getPosition()); 
       pos = cursor.getPosition(); 
      ImageButton ibDel =(ImageButton)view.findViewById(R.id.imageButton1); 
      ibDel.setOnClickListener(new OnClickListener() { 

       @Override 
       public void onClick(View v) { 
        // TODO Auto-generated method stub 
      //  Toast.makeText(ReminderListActivity.this, "Hello", Toast.LENGTH_SHORT).show(); 

        lvRemind.setOnItemClickListener(new OnItemClickListener() { 

         @Override 
         public void onItemClick(AdapterView<?> arg0, View arg1, 
           int arg2, long arg3) { 
          // TODO Auto-generated method stub 
          Toast.makeText(ReminderListActivity.this, ""+lvRemind.getItemAtPosition(arg2), Toast.LENGTH_SHORT).show(); 
         } 
        }); 
       } 
      }); 
     } 

     @Override 
     public View newView(Context context, Cursor cursor, ViewGroup parent) { 
      // TODO Auto-generated method stub 
      LayoutInflater inflater = LayoutInflater.from(parent.getContext()); 

       View retView = inflater.inflate(R.layout.list_remind, parent, false); 

       return retView; 
     } 

    } 

} 

如何从自定义列表视图中删除特定项目。我在自定义列表视图中添加了按钮。我想使用该位置上的特定按钮删除项目。

Answer 1

至于删除东西，你需要从ADAPTER中删除不是一个列表。您不需要保留自己的项目副本（除非您将其用于其他项目），因为阵列中存在项目列表。您需要致电adapter.remove(item)而不是list.remove(item)

那么您只需使用您的ArrayAdapter的remove（）方法从列表中删除所需的项目。

一个可能的方式做到这一点是：

Object toRemove = arrayAdapter.getItem([POSITION]); 
arrayAdapter.remove(toRemove); 

另一种方法是修改ArrayList和调用notifyDataSetChanged（）上一个ArrayAdapter。

arrayList.remove([INDEX]); 
arrayAdapter.notifyDataSetChanged(); 

Answer 2

喜试试下面的代码从列表视图

Button button1 = (Button) findViewById(R.id.create_message); 
button1.setOnClickListener(new OnClickListener() 
public void onClick(View v) 
    { 
    MyDataObject.remove(positionToRemove); 
    adapter.notifyDataSetChanged(); 
    }  
} 
});