Send multiple emails from a GridView, selected by checkboxes

[Javascript version, codebehind version to be submitted by szlamany]

This code sample is useful if you want to open the user's email client (Outlook, Outlook Express, Windows Live Mail, etc.) from your ASP.NET page and if your gridview contains checkboxes to select to whom the email will go to.

http://www.vbforums.com/attachment.p...1&d=1206481195

In my ASPX, I first make the javascript.

Code:

---

<script type="text/javascript">
 

        Array.prototype.remove=function(str)
        {
          for(i=0;i<this.length;i++)
          {
            if(this[i]==str)
            {
                this.splice(i, 1);
            }
          }
        }

        var EmailAddresses = new Array();

        function AddRemoveEmailAddress(chk, emailaddress)
        {
            if(chk.checked == true)
            {
                EmailAddresses.push(emailaddress);
            }
            else
            {
                EmailAddresses.remove(emailaddress);
            }
           
        }
       
       
        function SendEmails()
        {
       
            var emailString = "";
           
            for(i=0;i<EmailAddresses.length;i++)
            {
                emailString += EmailAddresses[i] + ";";
            }
           
          document.location.href='mailto:' + emailString;
         
        }

    </script>

---

Then, setup the gridview and button.

Code:

---


 <div>
    <asp:GridView ID="Students" Runat="server" OnRowDataBound="Students_RowDataBound">
    <Columns>
    <asp:TemplateField>
    <ItemTemplate>
    <asp:CheckBox ID="chkSendMail" runat="server" />
    </ItemTemplate>
    </asp:TemplateField>
    </Columns>
    </asp:GridView>
    </div>
    <div>
    <input type="button" onclick="javascript:SendEmails();" value="Send" id="EmailButton" />
    </div>

---

Then in the codebehind, I first setup a dummy datatable.

vb Code:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
 
 
        Dim dt As New Data.DataTable()
        dt.Columns.Add("col1")
        dt.Columns.Add("col2")
        dt.Columns.Add("col3")
 
        Dim dr As Data.DataRow = dt.NewRow()
        dr.Item("col1") = "111"
        dr.Item("col2") = "222"
        dr.Item("col3") = "[email protected]"
 
        Dim dr2 As Data.DataRow = dt.NewRow()
        dr2.Item("col1") = "333"
        dr2.Item("col2") = "444"
        dr2("col3") = "[email protected]"
 
 
        Dim dr3 As Data.DataRow = dt.NewRow()
        dr3.Item("col1") = "555"
        dr3.Item("col2") = "666"
        dr3.Item("col3") = "[email protected]"
 
 
        dt.Rows.Add(dr)
        dt.Rows.Add(dr2)
        dt.Rows.Add(dr3)
 
 
 
        Students.DataSource = dt
        Students.DataBind()
 
 
 
    End Sub

And finally the main bit, the RowDataBound event wherein I give each checkbox an onClick javascript method to call which adds or removes the email address from the global javascript array defined earlier.

vb Code:

Protected Sub Students_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles Students.RowDataBound
        If e.Row.RowType = DataControlRowType.DataRow Then
            Dim chk As New CheckBox
            chk = e.Row.FindControl("chkSendMail")
            chk.Attributes.Add("onClick", "AddRemoveEmailAddress(this, '" & CType(e.Row.DataItem, Data.DataRowView).Item("col3").ToString() & "');")
 
 
        End If
    End Sub

Ta-daaaa.

Keywords:
email
gridview
checkboxes
client side