后一个代码块中的代码似乎是一个好的开始。你缺少的是创建和设置参数的值。换句话说，比如

The code you have in the latter code block seems like a good start. what you're missing is creating and setting the value of a parameter. In other words something like

OleDbDataAdapter da = new OleDbDataAdapter("Select * from [Customer Orders] Where [Order ID] = @OrderID", MAcon);
da.SelectCommand.Parameters.AddWithValue("@OrderID", PrdtID.Text);
DataTable dtbl = new DataTable();
da.Fill(dtbl);