Can I access different controls inside other formview controls? - asp.net

Question

I have several forms, each with their own DDL, that I'm using inside a page. I have them in different forms because I need different data sources for each DDL. When I press the Submit button, it gives me an error that it can't find the control "ddlCategory". I assume it is because it is in a different formview control. Here is the markup:
<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>
Here is the code behind:
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");
}
Again, it tells me that it can't find the control ddlCategory. I thought about putting them all in one formview, but how would I make different datasources for each of the dropdown lists? I also tried not having any formview controls at all and just using "this.[ID of the ddl]" but that gave me a null reference value. Any ideas on how to make this work?

Answer 1

Here's how I did it. I ended up putting all the DDLs inside one formview (I didn't realize I could specify different datasources for DDLs within a formview that has its own datasource) and putting the datasource that uses the property to use the value from the previous DDL. Works like a charm now.
<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" />
And the code behind:
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");
}