在android中从数据库中删除项目

如何解决在android中从数据库中删除项目

| 我有一点问题。我正试图从存储在数据库中的列表中删除一个项目。当我选择“删除列表”时，所有其他项目都将被删除，但我选择的项目不会被删除。我不明白我的错误在哪里。请帮忙。 这是我的代码：

public class IncercListe extends Activity {

    TextView txt;
    String value;
    Button btn;
    private ListView lv1;
    private AlertDialog alertDialog;
    private ArrayAdapter<String> m_adapter;
    Bundle bundle ;
    String item;
    private Cursor cursor;
    private ListDbAdapter db;

    private static final int MENU_CREATE = Menu.FirsT;
    private static final int MENU_RENAME=Menu.FirsT+1;
    private static final int MENU_EDIT = Menu.FirsT + 2;
    private static final int MENU_SEND=Menu.FirsT+3;
    private static final int MENU_DELETE=Menu.FirsT+4;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.list1);

        lv1=(ListView)findViewById(R.id.list);

        db=new ListDbAdapter(this);
        db.open();
        fillData();
        registerForContextMenu(lv1);

        lv1.setonItemClickListener(new OnItemClickListener()
         {

           public void onItemClick(AdapterView<?> parent,View v,int position,long id)
           {
               Intent j= new Intent(IncercListe.this,List.class);
               startActivity(j);
           }
         });

     public void onCreateContextMenu(ContextMenu menu,ContextMenuInfo menuInfo) {  
             menu.setHeaderTitle(\"Choose \");  
             menu.add(0,MENU_RENAME,\"Rename List\");  
             menu.add(0,MENU_EDIT,\"Edit List\");
             menu.add(0,MENU_SEND,\"Send List\");
             menu.add(0,MENU_DELETE,\"Delete List\");
        }    
    @Override
    public boolean onContextItemSelected(MenuItem mitem) {     
        switch (mitem.getItemId()) {  
            case MENU_RENAME:  
                rename();
                return true;  

            case MENU_EDIT: 
                   Intent j= new Intent(IncercListe.this,List.class);
                   startActivity(j);                
                return true; 

            case MENU_SEND:
                return true;

            case MENU_DELETE:
                AdapterContextMenuInfo info=(AdapterContextMenuInfo)mitem.getMenuInfo();
                db.delete(info.id);
                fillData();
                    return true;
            default:    
                return super.onContextItemSelected(mitem);  
        }
    }   
    public boolean onCreateOptionsMenu(Menu menu) {    
        menu.add(0,MENU_CREATE,\"New List\");//.setIcon(R.drawable.quit); 
        return true;
    }
    /* Handles item selections */
   public boolean onoptionsItemSelected (MenuItem item) {    
        switch (item.getItemId()) {    
            case MENU_CREATE:        
                createlist();
                return true;  
        }
        return false;
    }

    public void createlist() {    
        alertDialog = new AlertDialog.Builder(this).create();
        alertDialog.setTitle(\"New List\");
        alertDialog.setMessage(\"Enter name of new shopping list :\");

        final EditText edt=new EditText(this);
        alertDialog.setView(edt);
        alertDialog.setButton(\"OK\",new DialogInterface.OnClickListener() {
             public void onClick(DialogInterface dialog,int which) {
                      item =edt.getText().toString();
                      if (!item.equals(\"\")) db.create(item);
                      fillData();
                       return;
             }
         });
        alertDialog.setButton2(\"Cancel\",new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog,int which) {
                dialog.cancel();
                   return;
            }
        }); 
        alertDialog.show();

    }
    public void rename() {      
    }
    public void sendlist(){
    }    
    protected void onActivityResult(int requestCode,int resultCode,Intent intent){
        super.onActivityResult(requestCode,resultCode,intent);
        fillData();
    }
    private void fillData(){
        cursor=db.fetchAll();
        startManagingCursor(cursor);

        listadapter adapter=new SimpleCursorAdapter(this,R.layout.textview,cursor,new String[] {ListDbAdapter.KEY_TITLE},new int[] {R.id.txt1});
        lv1.setAdapter(adapter);
    }

}

解决方法

我不确定，但是您可能想调用db.delete（info.position）而不是db.delete（info.id）。