通过上下文菜单使用更新和删除选项的列表视图

Posted 2023-03-22

【中文标题】通过上下文菜单使用更新和删除选项的列表视图

【英文标题】：list view with update and delete option via contextmenu

【发布时间】：2013-10-11 02:11:29

【问题描述】：

我这里一头雾水，我想在deleting any item之后刷新listview。我只是使用intent 和call the same activity，但它不起作用。那么请提出任何其他技巧或想法。 my sample code 如下：

update_page.java

 protected Object adapter;

     @Override
    public void onCreate(Bundle savedInstanceState)
        

            super.onCreate(savedInstanceState);
            setContentView(R.layout.update_list);
            final ProgressDialog myPd_ring=ProgressDialog.show(update_page.this, "Please wait", "Login please wait..", true);
            myPd_ring.setCancelable(true);
            myPd_ring.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
            new Thread() 

                public void run() 

                try

                sleep(1000);

                 catch (Exception e) 

                Log.e("tag", e.getMessage());

                

                // dismiss the progress dialog

                myPd_ring.dismiss();

                

                .start();


            myview = (ListView)this.findViewById(R.id.list);
            ctx=this;





            database = act.getInstance().openOrCreateDatabase("contactsManager",
            SQLiteDatabase.CREATE_IF_NECESSARY, null);       
            Toast.makeText(getApplicationContext(), "Database is open", 1500).show();


       //  database=this.openOrCreateDatabase("contactsManager", SQLiteDatabase.CREATE_IF_NECESSARY,null);

            final String[] columnsone="_id","task_name","date_time";
            String[] columnstwo="task_name","date_time";
            int to[] = R.id.lbl_task,R.id.lbl_datetime; 
            c = database.query("contacts", columnsone, null, null, null, null, null);
            status=c.getCount();

            Toast.makeText(getApplicationContext(), "totle task :" +status, 1500).show();



             if(c!=null)
               

                Toast.makeText(getApplicationContext(), "in courser", 1500).show();
                SimpleCursorAdapter adapter=new 
                        SimpleCursorAdapter(update_page.this,R.layout.update_listview, c, columnstwo, to);
                Toast.makeText(getApplicationContext(), "records are in list", 1500).show();

                myview.setAdapter(adapter);


                        myview.setOnItemLongClickListener(new OnItemLongClickListener() 
                        

                            public boolean onItemLongClick(AdapterView<?> arg0,
                                    View record, int arg2, long arg3)
                            


                                update_page.this.registerForContextMenu(record);
                                /*task= ((TextView)record.findViewById(R.id.lbl_task)).getText().toString();
                                date_time1= ((TextView)record.findViewById(R.id.lbl_datetime)).getText().toString();
                                Toast.makeText(getApplicationContext(), "task is"+task, 1500).show();
                                database = act.getInstance().openOrCreateDatabase("contactsManager",
                                        SQLiteDatabase.CREATE_IF_NECESSARY, null);    

                                String query = "SELECT _id FROM contacts WHERE task_name='"+task + "&date_time="+date_time1+"'";


                                c=database.rawQuery(query, null);
                                 c.moveToNext();

                                new_id=c.getInt(c.getColumnIndex("_id"));
                                */

                                return false;
                            

                        );
                
             
            //@Override 
            public boolean onContextItemSelected(MenuItem item)
            
                AdapterContextMenuInfo menuInfo = (AdapterContextMenuInfo)item.getMenuInfo();
                int choice = item.getItemId();
                switch(choice)
                
                case 1:
                    Toast.makeText(getApplicationContext(), "Update Task", 2000).show();

                    /*Intent op_intent = new Intent(update_page.this,MainActivity.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);

                    op_intent.putExtra("task_id", new_id);
                    op_intent.putExtra("task", task);
                    op_intent.putExtra("datetime", date_time1);

                    update_page.this.startActivity(op_intent);*/

                    break;

                case 2:


                    Toast.makeText(getApplicationContext(), "position :" +new_id , 2000).show();

                    String table_name = "contacts";
                    String where = "task_name='"+task+ "&date_time="+date_time1+"'";
                    String[] whereArgs = null;
                    database.delete(table_name, where, whereArgs);  
                     //over

                        c.close();
                        database.close();
                        Toast.makeText(getApplicationContext(), "Task Deleted Successfully", 1500).show();

                        update_page.this.startActivity(new Intent(update_page.this, update_page.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));

                    break;

                

                return super.onContextItemSelected(item);
            


            @Override
            public void onCreateContextMenu(ContextMenu menu, View v,
                    ContextMenuInfo menuInfo)
            
                menu.add(0,1,0,"Update Task");
                menu.add(0,2,0,"Delete");

                super.onCreateContextMenu(menu, v, menuInfo);
            


    

【问题讨论】：

这将有助于vogella.com/articles/androidSQLite/article.html

只关注“4.教程：使用SQLite”，不要关注“5.内容提供者和共享数据”部分。

@M-WaJeEh: 谢谢你先生..我会试试看。:-)

【参考方案1】：

您可以尝试 onResume() 方法并通知您列表。

@Override
public void onResume() 
    //set your adapter or referesh
    super.onResume();

【讨论】：

是的，兄弟，我认为这看起来不错..我会尝试 :) thnx 建议@Elesh

【参考方案2】：

当您对列表视图中的项目完成删除操作时，您只需调用适配器的adapter.notifydatasetchanged()。