asp.Net ObjectDataSource output parameter

一個查詢功能

有與DB溝通的Class，查詢方法會回拋DataTable

前端做GridView+ObjectDataSource

現在想要做後端驗證

驗證的方式是在傳入參數加入一個自訂類別 myValidClass的 output參數叫msg

在函式開頭就會先做驗證

有錯誤的時候msg的status屬性就會是false

並且msg的msg屬性會塞錯誤訊息

在網頁端的ODS加上

<asp:Parameter Type="Object" Direction="Output" Name="msg" />

並且加入OnSelected方法ods_Selected

<asp:ObjectDataSource runat="server" ID="ods" .... OnSelected="ods_Selected">

.cs端的ods_Selected方法

<div>
protected void ods_Selected(object sender, ObjectDataSourceStatusEventArgs e)</div>
<div>
&nbsp; &nbsp; {</div>
<div>
&nbsp; &nbsp; &nbsp; &nbsp;&nbsp;myValidClass&nbsp;msg = (myValidClass)e.OutputParameters["msg"];</div>
<div>
&nbsp; &nbsp; &nbsp; &nbsp; if (!msg.status)</div>
<div>
&nbsp; &nbsp; &nbsp; &nbsp; {</div>
<div>
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ScriptManager.RegisterStartupScript(this.Page, this.Page.GetType(), "alert", "alert('"+msg.msg+"');", true);</div>
<div>
&nbsp; &nbsp; &nbsp; &nbsp; }</div>
<div>
&nbsp; &nbsp; }</div>

DB溝通class的方法

<div>
public DataTable search(string parameter1, out&nbsp;myValidClass&nbsp;msg)</div>
<div>
{</div>
<div>
&nbsp; &nbsp; DataTable dt=new DataTable();</div>
<div>
&nbsp; &nbsp; //Do your validate method</div>
<div>
&nbsp; &nbsp; msg=new myValidClass();</div>
<div>
&nbsp; &nbsp; msg.status=true;</div>
<div>
&nbsp; &nbsp; if(string.IsNullOrEmpty(parameter1))</div>
<div>
&nbsp; &nbsp; {</div>
<div>
&nbsp; &nbsp; &nbsp; &nbsp; msg.status=false;</div>
<div>
&nbsp; &nbsp; &nbsp; &nbsp; msg.msg="參數1不可為空";</div>
<div>
&nbsp; &nbsp; }</div>
<div>
&nbsp; &nbsp; if(msg.status)</div>
<div>
&nbsp; &nbsp; {</div>
<div>
&nbsp; &nbsp; &nbsp; &nbsp; dt=db.getData(parameter1);</div>
<div>
&nbsp; &nbsp; }</div>
<div>
&nbsp; &nbsp; return dt;</div>
<div>
}</div>

這樣在做完查詢後ods_Selected方法就會檢查msg有沒有錯誤，

有錯誤就會alert錯誤訊息