Passing multiple argument through CommandArgument of Button in Asp.net

You can pass semicolon separated values as command argument and then split the string and use it.

<asp:TemplateField ShowHeader="false">
    <ItemTemplate>
       <asp:LinkButton ID="lnkCustomize" Text="Customize"  CommandName="Customize"  CommandArgument='<%#Eval("IdTemplate") + ";" +Eval("EntityId")%>'  runat="server"> 
       </asp:LinkButton>   
    </ItemTemplate>   
</asp:TemplateField>

at server side

protected void gridview_RowCommand(object sender, GridViewCommandEventArgs e)
{
      string[] arg = new string[2];
      arg = e.CommandArgument.ToString().Split(';');
      Session["IdTemplate"] = arg[0];
      Session["IdEntity"] = arg[1];
      Response.Redirect("Samplepage.aspx");
}

@Patrick's answer is a good idea, and deserves more credit!. You can have as many data items as you want, they are all separated, and can be used client side if necessary.

They can also be added declaratively rather than in code. I just did this for a GridView like this:

<asp:TemplateField HeaderText="Remind">
  <ItemTemplate>
    <asp:ImageButton ID="btnEmail"  
        data-rider-name="<%# ((Result)((GridViewRow) Container).DataItem).Rider %>"
        data-rider-email="<%# ((Result)((GridViewRow) Container).DataItem).RiderEmail %>"
        CommandName="Email" runat="server" ImageAlign="AbsMiddle" ImageUrl="~/images/email.gif" />
  </ItemTemplate> 
</asp:TemplateField>

In the RowCommand, you do this:

void gvMyView_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName == "Email")
    {
        var btnSender = (ImageButton)e.CommandSource;
        var riderName = btnSender.Attributes["data-rider-name"];
        var riderEmail = btnSender.Attributes["data-rider-email"];
        // Do something here
    }
}

So much cleaner than hacking all the values together with delimiters and unpacking again at the end.

Don't forget to test/clean any data you get back from the page, in case it's been tampered with!

My approach is using the attributes collection to add HTML data- attributes from code behind. This is more inline with jquery and client side scripting.

// This would likely be done with findControl in your grid OnItemCreated handler
LinkButton targetBtn = new LinkButton();


// Add attributes
targetBtn.Attributes.Add("data-{your data name here}", value.ToString() );
targetBtn.Attributes.Add("data-{your data name 2 here}", value2.ToString() );

Then retrieve the values through the attribute collection

string val = targetBtn.Attributes["data-{your data name here}"].ToString();

A little more elegant way of doing the same adding on to the above comment ..

<asp:GridView ID="grdParent" runat="server" BackColor="White" BorderColor="#DEDFDE"
                           AutoGenerateColumns="false"
                            OnRowDeleting="deleteRow"
                         GridLines="Vertical">
      <asp:BoundField DataField="IdTemplate" HeaderText="IdTemplate" />
      <asp:BoundField DataField="EntityId" HeaderText="EntityId"  />
    <asp:TemplateField ShowHeader="false">
        <ItemTemplate>
           <asp:LinkButton ID="lnkCustomize" Text="Delete"  CommandName="Delete"  CommandArgument='<%#Eval("IdTemplate") + ";" +Eval("EntityId")%>'  runat="server"> 
           </asp:LinkButton>   
        </ItemTemplate>   
    </asp:TemplateField>
     </asp:GridView>

And on the server side:

protected void deleteRow(object sender, GridViewDeleteEventArgs e)
{
    string IdTemplate= e.Values["IdTemplate"].ToString();
    string EntityId = e.Values["EntityId"].ToString();

   // Do stuff..
}

Either store it in the gridview datakeys collection, or store it in a hidden field inside the same cell, or join the values together. That is the only way. You can't store two values in one link.

If you want to pass two values, you can use this approach

<asp:LinkButton ID="RemoveFroRole" Text="Remove From Role" runat="server"
CommandName='<%# Eval("UserName") %>' CommandArgument='<%# Eval("RoleName") %>'
 OnClick="RemoveFromRole_Click" />

Basically I am treating {CommmandName,CommandArgument} as key value. Set both from database field. You will have to use OnClick event and use OnCommand event in this case, which I think is more clean code.

You can split the parameters using a separator (that must not be inside the parameter values - ex. "|"). Names of parameters must be valid names of the data source. Single quotes for the command arguments, and double quotes for the names of the parameters.

<%-- BUTTON VIEWCMD --%>
<asp:TemplateField HeaderText="" SortExpression="" ItemStyle-CssClass="widthP07 textAlignCenter">
    <ItemTemplate>
        <asp:Button ID="ButtonVIEWCMD" runat="server" Text="View Detail"
         CommandName="VIEWCMD" 
         CommandArgument='<%# Eval("param1") + "|" + Eval("param2") + "|" + Eval("param3") %>' />
                        
    </ItemTemplate>
</asp:TemplateField>

server code

/// <summary>
/// SET - Process GridView Row Commands
/// </summary>
protected void GridView_RowCommand(object sender, GridViewCommandEventArgs e)
{
    // INIT 
    string tempArguments = string.Empty;

    try
    {
        // CTRL - gridview row click
        switch (e.CommandName)
        {
            case "VIEWCMD":
                // GET 
                tempArguments = (string)(e.CommandArgument);
                // GET 
                string[] tempParam = tempArguments.Split('|');

                // GET 
                // tempParam[0];
                // tempParam[1];
                // tempParam[2];
                
                // .........

                break;

            default:
                break;
        }
    }
    catch (Exception ex)
    {
        // ERR .......
    }
}