Issues with an output param from a sproc using SQLDataSource

I have a stored proc that I'd like to return an output param from. I'm using a SQLDataSource and invoking the Update method which calls the sproc.

The proc looks like this currently:

ALTERproc [dbo].[k_sp_Load_IMIS_to_POP_x]

@.vcOutputMsgvarchar(255)OUTPUT

AS

SETNOCOUNTON;

select @.vcOutputMsg='asdf'

The code behind looks like this:

protectedvoid SqlDataSource1_Updated(object sender,SqlDataSourceStatusEventArgs e)

{

//handle error on return

string returnmessage = (string)e.Command.Parameters["@.vcOutputMsg"].Value;

}

On the page source side, the params are defined declaratively:

<UpdateParameters>

<asp:ParameterDirection="ReturnValue"Name="RETURN_VALUE"Type="Int32"/>

<asp:ParameterDirection="InputOutput"Name="vcOutputMsg"Type="String"/>

</UpdateParameters>

When I run it, the code behind throws the following exception - "Unable to cast object of type 'System.DBNull' to type 'System.String'"

PLEASE HELP! What am I doing wrong? Is there a better way to get output from a stored proc?

I got mine to work. Here's my example.

ASPX

<asp:gridview id="GridView1" runat="server" autogeneratecolumns="false" autogenerateeditbutton="true"datasourceid="SqlDataSource1"><columns><asp:boundfield datafield="ShipperID" headertext="ShipperID" readonly="True" /><asp:boundfield datafield="CompanyName" headertext="CompanyName" readonly="True" /><asp:boundfield datafield="Phone" headertext="Phone" readonly="True" /></columns></asp:gridview><asp:sqldatasource id="SqlDataSource1" runat="server" connectionstring="<%$ ConnectionStrings:NorthwindConnectionString%>"onupdated="SqlDataSource1_Updated" selectcommand="SELECT * FROM [Shippers]" updatecommand="sp_GetMessage"updatecommandtype="StoredProcedure"><updateparameters><asp:parameter direction="InputOutput" name="Message" size="50" type="String" /></updateparameters></asp:sqldatasource><asp:label id="Label1" runat="server" />

CODE-BEHIND

protected void SqlDataSource1_Updated(object sender, SqlDataSourceStatusEventArgs e){Label1.Text = e.Command.Parameters["@.Message"].Value.ToString();}

STORED PROCEDURE

ALTER PROCEDURE dbo.sp_GetMessage(@.MessageAS VARCHAR(50)OUTPUT)ASBEGINSELECT @.Message ='Hello World!'END

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Mine looked identical to yours except for the size on the output param. Once I added it in, it worked beautifully!! Not sure why it wasn't automatically declared when I configged the SQLDatasource to use the update method. But hey, it works now!!!

Thanks for the help!!!!!

Bill

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Mine didn't get created either, except I got another error actually referencing the absence of a size. I'm not too sure why you didn't receive the same. I also don't know why the Size attribute is needed.