Android非同步查詢方塊架AsyncQueryHandler使用簡介

1.首先是寫一個查詢的方法

//查詢資料    private void startQuery() {        Uri uri=Sms.CONTENT_URI;        String selection=" thread_id=?";        String[] selectionArgs=new String[]{thread_id};        //查詢        //projection 查詢的欄位        queryHandler.startQuery(0, null, uri, SMS_PROJECTION, selection, selectionArgs, " date DESC");    }

 

2.把需要查詢的欄位給抽取出來。

/**     * 將查詢所用的欄位處理出來     */    private static final String[] SMS_PROJECTION=new String[]{        "_id",        "address",        "date",        "type",        "body",    };    /**     * 當前欄位所對應的位置     */    private static final int ID_COLUMN_INDEX = 0;    private static final int ADDRESS_COLUMN_INDEX = 1;    private static final int DATE_COLUMN_INDEX = 2;    private static final int TYPE_COLUMN_INDEX = 3;    private static final int BODY_COLUMN_INDEX = 4;

 

3.然後繼承非同步查詢方塊架

private class QueryHandler extends AsyncQueryHandler{        public QueryHandler(ContentResolver cr) {            super(cr);                }                //查詢執行完成後悔執行這個方法        protected void onQueryComplete(int token, Object cookie, Cursor cursor) {            // TODO Auto-generated method stub            super.onQueryComplete(token, cookie, cursor);            //介面更新            adapter.changeCursor(cursor);        }    }