Prevent Page from "jumping" on submit

One Solution:

<script type="text/javascript">

          window.scrollTo = function (x, y) {

              return true;

          }

</script>

Logout when using ASP.NET memberships

What are we cooking today?

Logout when using ASP.NET memberships

RECIPE

  Protected Sub lnkLogout_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles lnkLogout.Click

        FormsAuthentication.SignOut()

        Response.Redirect(FormsAuthentication.LoginUrl)

    

  End Sub

Export from generic list of Objects to Excel (skipping provided column names)

What are we cooking today?

Export from generic list to Excel (skipping provided column names)

RECIPE

 Public Sub ExportToExcelFromList(fileName As String, listAID As List(Of AppInfoDay), Optional strArrListToSkip As String() = Nothing)

        'The Clear method erases any buffered HTML output.

        HttpContext.Current.Response.Clear()

        'The AddHeader method adds a new HTML header and value to the response sent to the client.

        HttpContext.Current.Response.AddHeader("content-disposition", String.Format("attachment; filename={0}", fileName & ".xls"))

        'The ContentType property specifies the HTTP content type for the response.

        HttpContext.Current.Response.ContentType = "application/ms-excel"

        'Implements a TextWriter for writing information to a string. The information is stored in an underlying StringBuilder.

        Using sw As New StringWriter()

            'Writes markup characters and text to an ASP.NET server control output stream. This class provides formatting capabilities that ASP.NET server controls use when rendering markup to clients.

            Using htw As New HtmlTextWriter(sw)

                '  Create a form to contain the List

                Dim table As New Table()

                Dim row As New TableRow()

                '---ADD COLS HEADER BASED ON OBJECT PROPERTIES

                For Each proinfo As PropertyInfo In New AppInfoDay().[GetType]().GetProperties()

                    '---SKIP UNDESIRED COLUMNS

                    If strArrListToSkip.Contains(proinfo.Name) Then

                        Continue For

                    Else

                        Dim hcell As New TableHeaderCell()

                        hcell.Text = proinfo.Name

                        row.Cells.Add(hcell)

                    End If

                Next

                table.Rows.Add(row)

                '---ADD ROWS WITH DATA

                For Each aid As AppInfoDay In listAID

                    Dim newRow As New TableRow()

                    For Each proinfo As PropertyInfo In aid.[GetType].GetProperties()

                        If strArrListToSkip.Contains(proinfo.Name) Then

                            Continue For

                        Else

                            Dim NewCell As New TableCell()

                            NewCell.Text = proinfo.GetValue(aid, Nothing).ToString()

                            newRow.Cells.Add(NewCell)

                        End If

                    Next

                    table.Rows.Add(newRow)

                Next

                '  render the table into the htmlwriter

                table.RenderControl(htw)

                '  render the htmlwriter into the response

                HttpContext.Current.Response.Write(sw.ToString())

                HttpContext.Current.Response.[End]()

            End Using

        End Using

    End Sub

 Sample code obtained from this link

Padding an string with a character (n times) in SQL Server

What are we cooking today?

Padding an string with a character (n times) in SQL Server

RECIPE

Declare @myString as varchar(10)

set @myString = '1234567'

select  RIGHT(REPLICATE('0', 10)

+ CAST(@mystring AS VARCHAR(10)), 10) PaddedResult

RESULT:

0001234567

Loading a dropdownlist from an XML file

What are we cooking today?

One Way of loading a dropdownlist from an XML file (sample: reading dates from an XML file)

RECIPE

The XML looks like:

<?xml version="1.0" encoding="utf-8" ?> <dates> <LocationA> <date>February 17, 2012</date> <date>March 29, 2012</date> <date>April 26, 2012</date> </LocationA> <LocationB> <date>March 29, 2012</date> <date>April 26, 2012</date> </LocationB> </dates>

The procedure:

Public Sub LoadDatesFromXMLFile(ByVal strOption As String) Try Dim doc As XDocument = XDocument.Load(MapPath("MyFile.xml")) If strOption = " LocationA " Then For Each element As XElement In doc.Descendants(" LocationA ") For Each XmlNode In element.Descendants("date") ddlAvailableDates.Items.Add(XmlNode.Value) Next Next Else For Each element As XElement In doc.Descendants("LocationB") For Each XmlNode In element.Descendants("date") ddlAvailableDates.Items.Add(XmlNode.Value) Next Next End If Catch ex As Exception lblError.Text = ex.Message End Try End Sub

Sorting a dropdownlist in VB.net

What are we cooking today?

One Way of Sorting a dropdownlist in VB.net

RECIPE

The Procedure

    Private Sub SortDropDown(ByVal ddl As DropDownList)

        '---Get listItems from dropDownList

        Dim ddlList As New ArrayList

        For Each li As ListItem In ddl.Items

            ddlList.Add(li)

        Next

        '---Sort arraylist

        ddlList.Sort(New ListItemComparer)

        '---Copy sorted list back into the dropDownList

        ddl.Items.Clear()

        For Each li As ListItem In ddlList

            ddl.Items.Add(li)

        Next

    End Sub

    

The Icomparer: I am using this because a listitem has text and value, and we just want to order by the text, which could be a person's name or a product( the criteria could be also the value like price, personId, year...)

 Public Class ListItemComparer : Implements IComparer

    Public Function Compare(ByVal x As Object, _

          ByVal y As Object) As Integer _

          Implements IComparer.Compare

        Dim a As ListItem = x

        Dim b As ListItem = y

        Dim c As New CaseInsensitiveComparer

        Return c.Compare(a.Text, b.Text)

    End Function

End Class

Disable caching (Browser back button problem)

When the user hit the back button a locally cached copy of the previous page is retrieved without notifying the server. As a result the Info is out of sync.

Solution 1 --> Disable caching (do not work for all browsers)

Code to disable caching (to be executed everytime thepage is loaded)

Response.Cache.SetCacheability(HttpCacheability.NoCache);

Response.Cache.SetExpires(Now.AddSeconds(-1));   //--- (-1) means the page already expired

Response.Cache.SetNoStore();  //--tell the page not to cache the page

Response.AppendHeader("Pragma", "no-cache");  //---adds a header to the HTTP response object

Solution 2 --> Use timestamps or random numbers to track pages and detect when a page is current