Putting links into a gridview dynamically (.net 4.5.1)

mdProgrammer · Oct 30, 2014

I have an application which was written in .NET 1.1 that used a datagrid that I would dynamically change a cell into a link based on the column and security settings. For example:

Column is an ID field and user has access to the record - Show a link.
Column is an ID field, and user does not have access to the recod - Don't show the link (normal text).
Column is not an ID field - Don't show the link (normal text).

I'm attempting to create a user control for .NET 4.5 (First major project using 4.5, and there's definately a lot of different, and nice features added, so it's a steep learning curve).

I've read that gridviews are the successors to datagrids, and I'm trying to create a usercontrol based on the gridview. Anyway, my problem is that when I change the text to a link in a gridview, it displays the HTML code (the HTML source shows <, &rt;, etc.). I even tried &rt;, < in the code, and it didn't work. However, with the datagrid, links would work just fine. (It's not just links, but any HTML code, like making text bold) Is there a way to make the HTML show up in an individual cell?

I know there are linkcolumns that I can add, but the ID field isn't always known, if it exists at all (as the control is used in multiple webforms).

This is some test code -

Code:

<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="DataGrids.aspx.vb" Inherits="WebApplication1.DataGrids" %>

<!DOCTYPE html>

<html xmlns="[URL unfurl="true"]http://www.w3.org/1999/xhtml">[/URL]
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
      <asp:Button ID="Button1" runat="server" Text="Button" />
      <br />

      <br />
      <strong>DataGrid</strong><asp:datagrid id="dgDataGrid" runat="server">
</asp:datagrid>

      <br />
      <strong>GridView</strong><asp:GridView ID="gvGridView" runat="server">
      </asp:GridView>
    
    </div>
    </form>
</body>
</html>

Code:

Public Class DataGrids
    Inherits System.Web.UI.Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    End Sub

  Protected Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

    Dim db As New dbData  ' Temporary class name from old application with hideiously non-refactored code. :)

    Dim dt As DataTable = db.getDataTable("SELECT 'Test' as 'ID_Column'", db.InventoryConnection)

    Dim dv As New DataView(dt)

    For i As Integer = 0 To dv.Table.Rows.Count - 1

      If dv.Table.Columns(0).ColumnName = "ID_Column" Then
        dv.Table.Rows(i).Item(0) = "<a href='[URL unfurl="true"]http://www.google.com'[/URL] target='_blank'>Google</a>"
      End If

    Next

    dgDataGrid.DataSource = dv
    gvGridView.DataSource = dv

    dgDataGrid.DataBind()
    gvGridView.DataBind()

  End Sub

End Class

jbenson001 · Oct 30, 2014

IF you don't want the actual HTML markup to show, you have to HTMLEncode() the text.

mdProgrammer · Oct 30, 2014

I did manage to find a work-around for what I want, via modifying the gridview after it has been databound. I also found and slightly modified some code I found on the Internet (the original assumed that the column would be found, so I added a boolean to check if that was the case or not. If not, return "Nothing").

Code:

.
.
.
    For i As Integer = 0 To gvGridView.Rows.Count - 1
      Dim id As String = GetColumnIndexByName(gvGridView.Rows(i), "ID_Column")

      If Not id = Nothing Then
        gvGridView.Rows(i).Cells(id).Text = "<a href='[URL unfurl="true"]http://www.google.com'[/URL] target='_blank'>Google</a>"

      End If
    Next

  End Sub

  Function GetColumnIndexByName(row As GridViewRow, columnName As String) As Object

    Dim columnIndex As Integer = 0
    Dim found As Boolean = False

    For Each cell As DataControlFieldCell In row.Cells


      If (cell.ContainingField.HeaderText = columnName) Then
        found = True
        Exit For
      End If
      columnIndex += 1 ' keep adding 1 while we don't have the correct name

    Next

    If found Then
      Return columnIndex
    End If
    Return Nothing
  End Function

mdProgrammer · Oct 30, 2014

To add, I'm not sure if it's the best practice, but it works.

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Putting links into a gridview dynamically (.net 4.5.1)

mdProgrammer

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jbenson001

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mdProgrammer

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mdProgrammer

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