How to design a HyperLinkColumn in Datagrid?

taoree · April 18th, 2004, 02:39 PM

:)Hi, everybody,

I am trying to design a HyperLinkcolumn in a Datagrid. I saved user information including email address in the database. When I recall these information, I want to display email address as HTML format. Some one told HyperLinkColumn can make it. But I don't know to write the code. Is there anybody can help me out? Thanks a lot.
Ray

planoie · April 19th, 2004, 09:29 AM

This will show the email with a standard mailto href:

<asp:HyperLinkColumn HeaderText="Click to email"
   DataNavigateUrlField="EmailDBField"
   DataNavigateUrlFormatString="mailto:{0}"
   DataTextField="EmailDBField" />

This will show the words "Click to email" with a standard mailto href:

<asp:HyperLinkColumn HeaderText="Click to email"
   DataNavigateUrlField="EmailDBField"
   DataNavigateUrlFormatString="mailto:{0}"
   Text="Click to email" />

Peter
-------------------------
Work smarter, not harder

taoree · April 19th, 2004, 05:37 PM

Thanks, Peter,
It works very well.
But how can I edit this hyperlinkcolumn when I place the datagrid into Edit mode? I know Boundcolumn turns into TextBox.
By the way, do you know where I can find the online library about datagrid category? Thanks a lot.

Here's my code followed.

Public Sub UpdateRecord(ByVal Sender As Object, _
                        ByVal E As DataGridCommandEventArgs)
  Dim EmailTextBox As TextBox = CType(E.Item.Cells(4).Controls(0), TextBox)
  Dim Professor_email As String = EmailTextBox.Text
End Sub

HTML:
      <asp:DataGrid id="dgProfessor" runat="server"
                    AutoGenerateColumns="False"
          <Columns>
          <asp:HyperLinkColumn HeaderText="User Email"
               DataNavigateUrlField="Professor_email"
               DataNavigateUrlFormatString="mailto:{0}"
               DataTextField="Professor_email" />
          <asp:EditCommandColumn ButtonType="LinkButton"
                        UpdateText="Save" CancelText="Cancel" EditText="Edit" />
        </Columns>
      </asp:DataGrid>

planoie · April 20th, 2004, 08:59 AM

Hyperlink columns are not editable. You'll have to change it to a template column.

You can find everything .net on the MSDN site. Here's the datagrid topic:
http://msdn.microsoft.com/library/de...classtopic.asp

taoree · April 22nd, 2004, 06:12 PM

thanks. Peter,
It's very helpful. By the way, do you know how can create a folder in the server under every user's name when I create them in a form submit? Or do you know where this part belongs to?
Thanks for your kindly help.
Ray

planoie · April 23rd, 2004, 11:04 AM

You can use the System.IO namespace to handle any filesystem tasks you wish to use.

When you need to deal with the physical location of a virtual path (i.e. a web address) you need to map the virtual path using Server.MapPath. So in the case of creating a folder for a user, you could do something like this:

Dim strUserName = "JohnDoeUser"
Dim strUserNamePath = Server.MapPath("~/users/" & strUserName)
System.IO.Directory.CreateDirectory(strUserNamePat h)

(The ~ in the MapPath call handles prefixing the virtual directory, if there is one, to the virtual path).

You'll need to make sure that the IIS runtime account has permissions to create files and folders on the server.

Peter
-------------------------
Work smarter, not harder

taoree · April 27th, 2004, 09:13 PM

Hi, Peter,
About editable hyperlink colum, I made a templateColumn as you said. It displays fine as what I want. hyperlink email for displaying and text for editing. But it seems I can't update the record. Error information was: Specified cast is not valid
How do you think I revise the bolded part?
Thanks.
Ray

<code>
Dim EmailTextBox As TextBox = CType(E.Item.Cells(4).Controls(0), TextBox) Dim Professor_email As String = EmailTextBox.Text
</code>
<Html>
<asp:TemplateColumn>
     <HeaderTemplate>
     <a>Eamil Address</a>
     </HeaderTemplate>
     <ItemTemplate>
         <asp:HyperLink id="HyperLink1"
          Text='<%# DataBinder.Eval(Container.DataItem, "Professor_email") %>'
          NavigateUrl='mailto:<%# DataBinder.Eval(Container.DataItem, "Professor_email") %>'
          runat="server"/>
     </ItemTemplate>
     <EditItemTemplate>
         <asp:TextBox
          Text='<%# DataBinder.Eval(Container.DataItem, "Professor_email") %>'
          runat="server"/>
          </EditItemTemplate>
</asp:TemplateColumn>
</html>

taoree · April 27th, 2004, 09:24 PM

Hi, Peter,
I fixed it, but I don't know why.
I changed the controls(0) to controls(1). It works now.
Can you tell me why?
Thanks.
Ray

planoie · April 28th, 2004, 09:11 AM

I have used controls(0) in the past and it hasn't given me problems.

Everything in the page is considered to be a control. Even static text containing whitespace. The problem might be due to this. Another thing you can try is to use the "FindControl" method of a control (i.e. the cell: Cells(4).FindControl...). This way you can search for the textbox control by name and not risk it breaking of the control index somehow changes.

Peter
-------------------------
Work smarter, not harder

taoree · April 28th, 2004, 04:00 PM

Thanks, Peter,

In my TemplateColume, the NavigateUrl part is wrong. the click-hyperlink can't give me the correct data. It gave me the following text. I need the retrieved record, such as mailto:[email protected].
Do you know how I can fix it?
Thanks.
Ray

NavigateUrl='mailto:<%# DataBinder.Eval(Container.DataItem, "Professor_email") %>'