Question

I have a gridview table that has three columns..fileID, uploadedBy and delete. Only the owner of the file can delete the file. How can I validate that the person deleting the file is the owner of the file. I have the login credentials and I have the uploadedBy string. I can get the login credentials but I cannot get the uploadedBy column from the delete link that is clicked.

<asp:TemplateField HeaderText="View" ItemStyle-HorizontalAlign="Center">
        <ItemTemplate>
          <asp:HyperLink ID="lnkView" runat="server" NavigateUrl='<%# Eval("Id", "~/ViewFile.aspx?Id={0}") %>' Text="View"></asp:HyperLink>
        </ItemTemplate>
      </asp:TemplateField>
      <asp:HyperLinkField ItemStyle-HorizontalAlign="Center" DataNavigateUrlFields="Id" DataNavigateUrlFormatString="~/DeleteFile.aspx?Id={0}" HeaderText="Delete" Text="Delete" />

 protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
  {        
     switch (e.Row.RowType)
    {
      case DataControlRowType.DataRow:
        FileInfo myFileInfo = (FileInfo)e.Row.DataItem;
        switch (myFileInfo.ContentType.ToLower())
        {
          case "image/pjpeg":         // .jpg files
          case "image/gif":           // .gif files
          case "application/msword":  // .doc files
          case "text/plain":         // .txt files 
          case "application/vnd.ms-excel":  
            // Do nothing. When the row contains a viewable type, 
            // we want the View link to be enabled.
            break;
          default:
            // Find the View link and disable it.
            HyperLink myLink = (HyperLink)e.Row.FindControl("lnkView");
            myLink.Enabled = false;
            break;
        }
        break;
    }
  }

Answer 1

You can use the RowDataBound event and check UpdatedBy with the Current logined user. If it is not the same user, simply hide the delete button.

 protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        System.Data.DataRow dr = ((System.Data.DataRowView)e.Row.DataItem).Row;

        if (dr["uploadedBy"].ToString() != HttpContext.Current.User.Identity.Name)
        {
            ((Button)e.Row.FindControl("btnDelete")).Visible = false;
        }
     }
 }