Question

I use below code :

.aspx

<asp:SqlDataSource ID="SqlDataSource1" ConnectionString="<%$ConnectionStrings:Con %>" runat="server" 
        SelectCommand="select * from DorePayvar" OnSelecting="selecting" 
        UpdateCommand="update DorePayvar set Name=@name" OnUpdating="SqlDataSource1_Updating">
        <UpdateParameters>
            <asp:Parameter Type="String" Name="name" DefaultValue="Sajjad" />
        </UpdateParameters>
        </asp:SqlDataSource> 

.cs

protected void SqlDataSource1_Updating(object sender, SqlDataSourceCommandEventArgs e)
    {
        e.Command.Parameters["name"].Value = "bvhjbjh";   
    }

but when i press update button occur below error

An SqlParameter with ParameterName ‘name’ is not contained by this
SqlParameterCollection.

Answer 1

You are missing the @ symbol.
The following should work :

protected void SqlDataSource1_Updating(object sender, SqlDataSourceCommandEventArgs e)
{
    e.Command.Parameters["@name"].Value = "bvhjbjh";   
}

For more information on using parameters with sqldatasource check this out.