Hi vinpes,
If you don't want to call in button click then you need to call ReloadData in page load event like below.
Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
ReloadDATA()
End Sub
Private Sub ReloadDATA()
Dim x As String() = New String(3) {"Mango", "Apple", "Orange", "Banana"}
Dim y As Integer() = New Integer(3) {200, 112, 55, 96}
Chart1.Series(0).Points.DataBindXY(x, y)
Chart1.Series(0).ChartType = SeriesChartType.Pie
Chart1.ChartAreas("ChartArea1").Area3DStyle.Enable3D = True
Chart1.Legends(0).Enabled = True
End Sub
Protected Sub btnExportPDF_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim pdfDoc As Document = New Document(PageSize.A4, 10.0!, 10.0!, 10.0!, 0.0!)
PdfWriter.GetInstance(pdfDoc, Response.OutputStream)
pdfDoc.Open()
Dim stream As MemoryStream = New MemoryStream
Chart1.SaveImage(stream, ChartImageFormat.Png)
Dim chartImage As iTextSharp.text.Image = iTextSharp.text.Image.GetInstance(stream.GetBuffer)
chartImage.ScalePercent(75.0!)
pdfDoc.Add(chartImage)
pdfDoc.Close()
Response.ContentType = "application/pdf"
Response.AddHeader("content-disposition", "attachment;filename=Chart.pdf")
Response.Cache.SetCacheability(HttpCacheability.NoCache)
Response.Write(pdfDoc)
Response.End()
End Sub