问题

是这样的C#开发winform datagrid控件捆绑taskdataset 调式在这一行 出现问题
taskDataAdapter.Update(taskDataSet.Tables[TASK_TABLE].Select("","",DataViewRowState.Added));
提示 对象名＇serach_task＇无效　
我想问下这是什么原因引起的　serach_task　是我的一张表的名字try
{

_conn.Open();
trans=_conn.BeginTransaction();
taskDataAdapter.InsertCommand.Transaction=trans;
taskDataAdapter.DeleteCommand.Transaction=trans;
taskDataAdapter.UpdateCommand.Transaction=trans;
taskDataAdapter.Update(taskDataSet.Tables[TASK_TABLE].Select("","",DataViewRowState.Added));
taskDataAdapter.Update(taskDataSet.Tables[TASK_TABLE].Select("","",DataViewRowState.ModifiedCurrent));
taskDataAdapter.Update(taskDataSet.Tables[TASK_TABLE].Select("","",DataViewRowState.Deleted));
trans.Commit();
}