Refresh 方法范例 (VB)

<p><font face="Verdana">Refresh 方法范例 (VB)</font></p><font face="Verdana">
<p><br/>本范例演示使用 Refresh 方法来刷新存储过程 Command 对象的 Parameters 集合。</p>
<p>Public Sub RefreshX()</p>
<p>&nbsp;&nbsp;&nbsp; Dim cnn1 As ADODB.Connection<br/>&nbsp;&nbsp;&nbsp; Dim cmdByRoyalty As ADODB.Command<br/>&nbsp;&nbsp;&nbsp; Dim rstByRoyalty As ADODB.Recordset<br/>&nbsp;&nbsp;&nbsp; Dim rstAuthors As ADODB.Recordset<br/>&nbsp;&nbsp;&nbsp; Dim intRoyalty As Integer<br/>&nbsp;&nbsp;&nbsp; Dim strAuthorID As String<br/>&nbsp;&nbsp;&nbsp; Dim strCnn As String</p>
<p>&nbsp;&nbsp;&nbsp; ' Open connection.<br/>&nbsp;&nbsp;&nbsp; Set cnn1 = New ADODB.Connection<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; strCnn = "Provider=sqloLEDb;" &amp; _<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; "Data Source=srv;Initial Catalog=Pubs;User Id=sa;Password=; "<br/>&nbsp;&nbsp;&nbsp; cnn1.Open strCnn<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br/>&nbsp;&nbsp;&nbsp; ' Open a command object for a stored procedure<br/>&nbsp;&nbsp;&nbsp; ' with one parameter.<br/>&nbsp;&nbsp;&nbsp; Set cmdByRoyalty = New ADODB.Command<br/>&nbsp;&nbsp;&nbsp; Set cmdByRoyalty.ActiveConnection = cnn1<br/>&nbsp;&nbsp;&nbsp; cmdByRoyalty.CommandText = "byroyalty"<br/>&nbsp;&nbsp;&nbsp; cmdByRoyalty.CommandType = adCmdStoredProc<br/>&nbsp;&nbsp;&nbsp; cmdByRoyalty.Parameters.Refresh<br/>&nbsp;&nbsp;&nbsp; <br/>&nbsp;&nbsp;&nbsp; ' Get paramater value and execute the command, <br/>&nbsp;&nbsp;&nbsp; ' storing the results in a recordset.<br/>&nbsp;&nbsp;&nbsp; intRoyalty = Trim(InputBox("Enter royalty:"))<br/>&nbsp;&nbsp;&nbsp; cmdByRoyalty.Parameters(1) = intRoyalty<br/>&nbsp;&nbsp;&nbsp; Set rstByRoyalty = cmdByRoyalty.Execute()<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <br/>&nbsp;&nbsp;&nbsp; ' Open the Authors table to get author names for display.<br/>&nbsp;&nbsp;&nbsp; Set rstAuthors = New ADODB.Recordset<br/>&nbsp;&nbsp;&nbsp; rstAuthors.Open "Authors", cnn1, , , adCmdTable<br/>&nbsp;&nbsp;&nbsp; <br/>&nbsp;&nbsp;&nbsp; ' Print current data in the recordset, adding<br/>&nbsp;&nbsp;&nbsp; ' author names from Authors table.<br/>&nbsp;&nbsp;&nbsp; debug.Print "Authors with " &amp; intRoyalty &amp; " percent royalty"<br/>&nbsp;&nbsp;&nbsp; Do While Not rstByRoyalty.EOF<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; strAuthorID = rstByRoyalty!au_id<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Debug.Print "&nbsp;&nbsp;&nbsp; " &amp; rstByRoyalty!au_id &amp; ", ";<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; rstAuthors.Filter = "au_id = '" &amp; strAuthorID &amp; "'"<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Debug.Print rstAuthors!au_fname &amp; " " &amp; _<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; rstAuthors!au_lname<br/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; rstByRoyalty.MoveNext<br/>&nbsp;&nbsp;&nbsp; Loop</p>
<p>&nbsp;&nbsp;&nbsp; rstByRoyalty.Close<br/>&nbsp;&nbsp;&nbsp; rstAuthors.Close<br/>&nbsp;&nbsp;&nbsp; cnn1.Close<br/>&nbsp;&nbsp;&nbsp; <br/>End Sub</p>
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