ASP.Net Draw Google like Calendar to add/delete/show events

Function call in code behind:

  lblCal.Text = DrawCalender(Session("month"), Session("year"), shrink)



Function Module to Draw Calander:
(dayevent function will connect to your database to get events as datatable and render it into calander dates.
  myquery = "select   project , concat(coord, ' Venue-', venue, ' ') as coord, start_dt,day(start_dt) as day, project as highlight, concat(' on ', date_format(start_dt,'%d.%m.%y')) as description, if(start_dt=end_dt, project ,concat(project,'(',convert(day(start_dt),char(2)),'-', convert(day(end_dt),char(2)),')')) as trim , 'PRT/PDRM' as type, '' as file, uid from diaryPRT where month(prtmonth) = " & Session("month") & " and year(prtmonth) = " & Session("year")
 ViewState("mydata") = dbOperation.getCalenderData(myquery)
)

Function DrawCalender(ByVal month As Integer, ByVal year As Integer, Optional ByVal shrink As Boolean = False) As String

        Try

            'to hold current date of this day for presentation peropse

            Dim today As Date = New Date(Now.Year, Now.Month, Now.Day)

            'object of passed month and year

            Dim currentDate As Date = New Date(year, CInt(month), 1)

            'array hold days of week

            Dim days() As String = New String() {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}

            'temp holder to hold week name from array above

            Dim day As String

            'number of days in selected month

            Dim numDays As Integer = Date.DaysInMonth(year, month)

            Dim index, position As Integer

            Dim returnData As String = ""

            '1st day of month day number

            Dim offset As Integer = currentDate.DayOfWeek()

            'MsgBox(offset)

            Dim mode1 = If(Not Session("mode") Is Nothing, "&mode=" & Session("mode"), "")

            returnData = ""

            returnData &= " "

            Dim lastmonth As Date = New DateTime(currentDate.Year, currentDate.Month, 1).AddMonths(-1)

            returnData &= " & lastmonth.Month & "&year=" & lastmonth.Year & mode1 & ">" & MonthName(lastmonth.Month) & "-" & lastmonth.Year.ToString & ""

            returnData &= "" & MonthName(currentDate.Month) & " - " & currentDate.Year & "

"

            Dim nextmonth As Date = New DateTime(currentDate.Year, currentDate.Month, 1).AddMonths(1)

            returnData &= " & nextmonth.Month & "&year=" & nextmonth.Year & mode1 & ">" & MonthName(nextmonth.Month) & "-" & nextmonth.Year.ToString & ""

            returnData &= "

"

            returnData &= " "

            For Each day In days

                returnData &= "" & day & "

"

            Next

            returnData &= "

"

            position = 0

            Dim shrinkhieght = 100

            For index = 1 - offset To numDays

                If position Mod 7 = 0 Then

                    returnData &= " "

                End If

                shrinkhieght = If((shrink And index <= 15), 40, 180)

                If index < 1 Then

                    returnData &= "-"

                ElseIf index = today.Day AndAlso year = today.Year AndAlso month = today.Month Then

                    returnData &= " & shrinkhieght & """ bgcolor=""#E0FFFF"">

& (index).ToString() & "," & month.ToString & ", " & year.ToString & " )""  style = ""width:100%;height:100%;z-index:1000;"" > " & _

                                     "         " & (index).ToString() & "

" & dayEvents(index) & ""

                Else

                    returnData &= " & shrinkhieght & """>

& (index).ToString() & "," & month.ToString & ", " & year.ToString & " )""  style = ""width:100%;height:100%;z-index:1000;"" > " & _

                                      "         " & (index).ToString() & "

" & dayEvents(index) & ""

                    '    "         " & (index).ToString() & "

" & dayEvents(index) & "

"

                End If

                position += 1

                If position Mod 7 = 0 Then returnData &= "

"

            Next

            If position Mod 7 <> 0 Then

                For index = 1 To 7 - (position Mod 7)

                    returnData &= "-"

                Next

                returnData &= "

"

            End If

            returnData &= "

"

            Return returnData

        Catch exp As Exception

            Return "Error: Please refresh the page : " & exp.Message & year & month

        End Try

    End Function

    Private Function Years() As String()

        Dim str(10) As String

        Dim index As Integer

        For index = 0 To str.Length - 1

            str(index) = Now.Year - str.Length + index + 1

        Next

        Return str

    End Function

    Private Function dayEvents(ByVal myday As String) As String

        Try

            Dim tmp As String = ""

            Dim detail As String = ""

            Dim bubble As String = ""

            Dim dt As New System.Data.DataTable

            dt = CType(ViewState("mydata"), System.Data.DataTable)

            Dim i As Integer = dt.Rows.Count

            If i = 0 Then

                Return "




"

            Else

                Dim j As Integer = 0

                Dim k As Integer = 1

                While j < i

                    'highlight,reviewby,reviewdate, day , project , description, trim, type, file , uid

                    If dt.Rows(j).Item(3).ToString() = myday Then

                        If j Mod 2 = 0 Then

                            tmp = tmp & " "

                            detail = detail & ""

                        Else

                            tmp = tmp & " "

                            detail = detail & ""

                        End If

                        Dim rdate As Date = dt.Rows(j).Item(2).ToString

                        detail = (k).ToString & ": " & dt.Rows(j).Item(0).ToString() & " " & dt.Rows(j).Item(5).ToString() & "

- " & dt.Rows(j).Item(1).ToString() & " Loc/Proj: " & dt.Rows(j).Item(4).ToString() & "


"

                        bubble = "onMouseOver=""return overlib('" & detail & "',CAPTION,'" & dt.Rows(j).Item(7).ToString() & ": " & rdate.ToString("dd-MM-yyyy") & "',TEXTSIZE,'14px',CAPTIONSIZE,'14px',CAPCOLOR,'#000000',HAUTO,VAUTO, FGCOLOR, '#ffffff', BGCOLOR, '#C1DAD7', BORDER, 1, CAPTIONFONT, 'Garamond', TEXTFONT, 'Courier');"" onMouseOut=""nd();"""

                        Dim link = "javascript:void(0);"

                        Dim icon = ""

                        If Not String.IsNullOrEmpty(dt.Rows(j).Item(8).ToString()) Then

                            link = "/ppm/upload/diary/" & dt.Rows(j).Item(8).ToString

                            icon = " & Right(dt.Rows(j).Item(8).ToString, 3) & ".gif border=0 align=middle height=13px onerror=" & Chr(34) & "this.src='images/file.gif';" & Chr(34) & "/>"

                        End If

                        tmp = tmp & " & bubble & " style='text-decoration:none'>" & dt.Rows(j).Item(6).ToString() & icon & "

"

                        k = k + 1

                    End If

                    j = j + 1

                End While

                Return " " & tmp & "

"

            End If

        Catch exp As Exception

            Return "Error: Please refresh the page : " & exp.Message & myday

        End Try

    End Function

Output:

To made the code complex for add/delete event Use popup control/or open other page and write code for that.