我可以访问其他formview控件内的不同控件吗？

Question

我有几种形式，每种都有自己的DDL，我在页面中使用。我有他们不同的形式，因为我需要每个DDL不同的数据源。当我按提交按钮时，它给我一个错误，它无法找到控件“ddlCategory”。我认为这是因为它在不同的formview控件中。下面是标记：

<asp:FormView ID="FormView1" runat="server" DataKeyNames="ID" 
DataSourceID="AccessDataSource1" DefaultMode="Insert" > 
<InsertItemTemplate>  
    Select a Category:<br /> 
    <asp:DropDownList ID="ddlCategory" runat="server" AutoPostBack="True" 
     DataSourceID="AccessDataSource1" DataTextField="ORG_NAME" 
     DataValueField="ID"> 
    </asp:DropDownList> 
</InsertItemTemplate> 
</asp:FormView> 
<asp:AccessDataSource ID="AccessDataSource1" runat="server" 
DataFile="~/App_Data/webvideos.mdb" 
SelectCommand="SELECT * FROM [ORGANIZATIONS]"/> 
<br /> 
<asp:FormView ID="FormView2" runat="server" DataKeyNames="ID" 
DataSourceID="AccessDataSource2" DefaultMode="Insert" > 
<InsertItemTemplate> 
    Select an Organization:<br /> 
    <asp:DropDownList ID="ddlOrg" runat="server" 
     DataSourceID="AccessDataSource2" DataTextField="SectionName" 
     DataValueField="ID"> 
    </asp:DropDownList> 
</InsertItemTemplate> 
</asp:FormView>  
<asp:AccessDataSource ID="AccessDataSource2" runat="server" 
DataFile="~/App_Data/webvideos.mdb" 
SelectCommand="SELECT ID,SectionName FROM ORG_SECTIONS WHERE OrgID=@OrgID "> 
<SelectParameters> 
    <asp:ControlParameter ControlID="ddlCategory" 
     PropertyName="SelectedValue" 
     Name="ID" Type="String" 
     DefaultValue="" /> 
</SelectParameters> 
</asp:AccessDataSource> 
<br /> 
<asp:FormView ID="FormView3" runat="server" DataKeyNames="ID" 
DataSourceID="AccessDataSource3" DefaultMode="Insert" > 
<InsertItemTemplate> 
    Select an Attorney:<br /> 
    <asp:DropDownList ID="ddlAtty" runat="server" 
     DataSourceID="AccessDataSource3" DataTextField="Expr1" DataValueField="ATTY_ID"> 
    </asp:DropDownList> 
</InsertItemTemplate> 
</asp:FormView> 
<asp:AccessDataSource ID="AccessDataSource3" runat="server" 
DataFile="~/App_Data/webvideos.mdb" 
SelectCommand="SELECT ATTY_ID, NAME & ' ' & INITIAL & ' ' & LASTNAME AS Expr1 FROM ATTORNEYS ORDER BY NAME & INITIAL & ' ' & LASTNAME"> 
</asp:AccessDataSource> 

这里是后面的代码：

protected void AddRec(object sender, EventArgs e) 
{ 
    DropDownList ddlCategory = (DropDownList)FormView1.FindControl("ddlCategory"); 
    DropDownList ddlOrg = (DropDownList)FormView2.FindControl("ddlOrg"); 
    DropDownList ddlAtty = (DropDownList)FormView3.FindControl("ddlAtty"); 

    string constr = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\webvideos.mdb;"; 
    string cmdstr = "INSERT INTO [Org_Sec_Atty] ([OrgID], [SecID], [AttyID]) VALUES (?, ?, ?)"; 


    OleDbConnection con = new OleDbConnection(constr); 
    OleDbCommand com = new OleDbCommand(cmdstr, con); 

    con.Open(); 
    com.Parameters.AddWithValue("@OrgID", ddlCategory.SelectedValue); 
    com.Parameters.AddWithValue("@SecID", ddlOrg.SelectedValue); 
    com.Parameters.AddWithValue("@AttyID", ddlAtty.SelectedValue); 
    com.ExecuteNonQuery(); 
    con.Close(); 
    Response.Redirect("ManageProfAffs.aspx"); 
} 

再次，它告诉我，它无法找到控制ddlCategory。我想将它们全部放在一个formview中，但是我如何为每个下拉列表创建不同的数据源？我也试过没有任何formview控件，只是使用“this。[ddl]的ID”，但是这给了我一个空引用值。关于如何使这项工作的任何想法？

Answer 1

下面是我做到的。我最终将所有DDL放在一个formview中（我没有意识到我可以在具有自己的数据源的formview中为DDL指定不同的数据源），并将使用该属性的数据源使用前一个DDL中的值。现在就像魅力一样。

<asp:AccessDataSource ID="AccessDataSource1" runat="server" 
    DataFile="~/App_Data/webvideos.mdb" 
    SelectCommand="SELECT * FROM [ORGANIZATIONS]"/> 

<asp:AccessDataSource ID="AccessDataSource3" runat="server" 
    DataFile="~/App_Data/webvideos.mdb" 
    SelectCommand="SELECT ATTY_ID, NAME & ' ' & INITIAL & ' ' & LASTNAME AS Expr1 FROM ATTORNEYS ORDER BY NAME & INITIAL & ' ' & LASTNAME"> 
</asp:AccessDataSource> 
<br /> 
<asp:FormView ID="FormView1" runat="server" DataKeyNames="ID" 
    DataSourceID="AccessDataSource1" DefaultMode="Insert" > 
    <InsertItemTemplate>  
     Select a Category:<br /> 
     <asp:DropDownList ID="ddlCategory" runat="server" AutoPostBack="True" 
      DataSourceID="AccessDataSource1" DataTextField="ORG_NAME" 
      DataValueField="ID"> 
     </asp:DropDownList> 
    <br /> 
    <asp:AccessDataSource ID="AccessDataSource2" runat="server" 
     DataFile="~/App_Data/webvideos.mdb" 
     SelectCommand="SELECT ID,SectionName FROM ORG_SECTIONS WHERE OrgID=@OrgID "> 
     <SelectParameters> 
      <asp:ControlParameter ControlID="ddlCategory" 
       PropertyName="SelectedValue" 
       Name="ID" Type="String" 
       DefaultValue="" /> 
     </SelectParameters> 
    </asp:AccessDataSource> 
     Select an Organization:<br /> 
     <asp:DropDownList ID="ddlOrg" runat="server" 
      DataSourceID="AccessDataSource2" DataTextField="SectionName" 
      DataValueField="ID"> 
     </asp:DropDownList> 
<br /> 
     Select an Attorney:<br /> 
     <asp:DropDownList ID="ddlAtty" runat="server" 
      DataSourceID="AccessDataSource3" DataTextField="Expr1" DataValueField="ATTY_ID"> 
     </asp:DropDownList> 
    </InsertItemTemplate> 
</asp:FormView> 
<br /> 
<asp:Button ID="Button1" runat="server" Text="Submit" OnClick="AddRec" /> 

而后面的代码：

protected void AddRec(object sender, EventArgs e) 
{ 
    DropDownList ddlCategory = (DropDownList)FormView1.FindControl("ddlCategory"); 
    DropDownList ddlOrg = (DropDownList)FormView1.FindControl("ddlOrg"); 
    DropDownList ddlAtty = (DropDownList)FormView1.FindControl("ddlAtty"); 

    string constr = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\webvideos.mdb;"; 
    string cmdstr = "INSERT INTO [Org_Sec_Atty] ([OrgID], [SecID], [Atty_ID]) VALUES (?, ?, ?)"; 


    OleDbConnection con = new OleDbConnection(constr); 
    OleDbCommand com = new OleDbCommand(cmdstr, con); 

    con.Open(); 
    com.Parameters.AddWithValue("@OrgID", ddlCategory.SelectedValue); 
    com.Parameters.AddWithValue("@SecID", ddlOrg.SelectedValue); 
    com.Parameters.AddWithValue("@AttyID", ddlAtty.SelectedValue); 
    com.ExecuteNonQuery(); 
    con.Close(); 
    Response.Redirect("ManageProfAffs.aspx"); 
}