After Export to Excel File error while opening using xmlwriter in silverlight

Question

Can one help me in fixing following issue after to export to excel had done iam getting following error message 
"The file you are trying to open, 'test.xls', is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a trusted source before opening the file. Do uou want to open the file now ?"
If i click Yes file opens correctly but it shows above message . Can any one suggest me how to avoid this programatically with the following code.
I tried by changing the file saving as  .xls to .xlsx  but it doesnt works.
Public Sub Export()
Dim ss As String = "urn:schemas-microsoft-com:office:spreadsheet"
Dim DataType As String
Dim DataValue As Object
'Dim DataView As C1.Silverlight.Data.DataView = m_DataGrid.ItemsSource
'Dim ItemsSource As C1.Silverlight.Data.DataTable = DataView.Table
Dim XmlSettings As XmlWriterSettings
Dim ColumnBinding As Binding
Dim FieldName As String
Dim DataGridColumn As C1.Silverlight.DataGrid.DataGridColumn
Dim ColumnIndex As Integer
Dim J As Integer
Dim DataGridRow As C1.Silverlight.DataGrid.DataGridRow
Dim CommonUtil As New GoldCRM.Core.Common.Util
Dim PropertyInfo As System.Reflection.PropertyInfo
Dim CellFormat As String
Try
If m_DataGrid.Rows.Count = 0 Then Exit Try
XmlSettings = New XmlWriterSettings
XmlSettings.Indent = True
XmlSettings.NewLineOnAttributes = False
Using myXML As XmlWriter = XmlWriter.Create(m_Stream, XmlSettings)
With myXML
.WriteStartDocument()
.WriteProcessingInstruction("mso-application", "progid=" & ControlChars.Quote & "Excel.Sheet" & ControlChars.Quote)
.WriteStartElement("Workbook", ss)
.WriteStartElement("DocumentProperties", "urn:schemas-microsoft-com:office:office")
.WriteElementString("Author", m_DocumentProperties.Author)
.WriteElementString("LastAuthor", String.Format("{0} {1}", Application.Current.Resources("EmpFirstName"), Application.Current.Resources("EmpLastName")))
.WriteElementString("Created", m_DocumentProperties.Created)
.WriteElementString("LastSaved", m_DocumentProperties.LastSaved)
.WriteElementString("Company", Application.Current.Resources("REPORTINGSITENAME"))
.WriteElementString("Version", m_DocumentProperties.Version)
.WriteEndElement() 'Document Properties
.WriteStartElement("ExcelWorkbook", "urn:schemas-microsoft-com:office:excel")
.WriteElementString("WindowHeight", m_WorkbookProperties.WindowHeight)
.WriteElementString("WindowWidth", m_WorkbookProperties.WindowWidth)
.WriteElementString("WindowTopX", m_WorkbookProperties.WindowTopX)
.WriteElementString("WindowTopY", m_WorkbookProperties.WindowTopY)
.WriteElementString("ProtectStructure", m_WorkbookProperties.ProtectStructure)
.WriteElementString("ProtectWindows", m_WorkbookProperties.ProtectWindows)
.WriteEndElement() 'Excel Workbook
.WriteStartElement("Styles")
For I As Integer = 0 To m_Styles.Count - 1
.WriteStartElement("Style")
.WriteAttributeString("ss", "ID", ss, m_Styles(I).ID)
If m_Styles(I).Name <> "" Then
.WriteAttributeString("ss", "Name", ss, m_Styles(I).Name)
End If
'ALIGNMENT LOGIC:
.WriteStartElement("Alignment")
If Not m_Styles(I).Alignment Is Nothing Then
If m_Styles(I).Alignment.Horizontal <> 0 Then
.WriteAttributeString("ss", "Horizontal", ss, m_Styles(I).Alignment.Horizontal.ToString)
End If
If m_Styles(I).Alignment.Vertical <> 0 Then
.WriteAttributeString("ss", "Vertical", ss, m_Styles(I).Alignment.Vertical.ToString)
End If
If m_Styles(I).Alignment.WrapText = True Then
.WriteAttributeString("ss", "WrapText", ss, "1")
End If
End If
.WriteEndElement()
'BORDER LOGIC:
.WriteStartElement("Borders")
.WriteStartElement("Border")
.WriteAttributeString("ss", "Position", ss, "Bottom")
.WriteAttributeString("ss", "LineStyle", ss, "Continuous")
.WriteAttributeString("ss", "Weight", ss, "1")
.WriteEndElement() 'Border
.WriteStartElement("Border")
.WriteAttributeString("ss", "Position", ss, "Left")
.WriteAttributeString("ss", "LineStyle", ss, "Continuous")
.WriteAttributeString("ss", "Weight", ss, "1")
.WriteEndElement() 'Border
.WriteStartElement("Border")
.WriteAttributeString("ss", "Position", ss, "Right")
.WriteAttributeString("ss", "LineStyle", ss, "Continuous")
.WriteAttributeString("ss", "Weight", ss, "1")
.WriteEndElement() 'Border
.WriteStartElement("Border")
.WriteAttributeString("ss", "Position", ss, "Top")
.WriteAttributeString("ss", "LineStyle", ss, "Continuous")
.WriteAttributeString("ss", "Weight", ss, "1")
.WriteEndElement() 'Border
.WriteEndElement() 'Borders
'FONT LOGIC:
.WriteStartElement("Font")
Dim myFont As Excel.Styles.Font = m_Styles(I).Font
.WriteAttributeString("ss", "FontName", ss, myFont.FontName.ToString)
.WriteAttributeString("ss", "Size", ss, myFont.Size)
.WriteAttributeString("ss", "Color", ss, myFont.Color.ToString.Remove(1, 2))
If myFont.Bold = True Then .WriteAttributeString("ss", "Bold", ss, "1")
If myFont.Italic = True Then .WriteAttributeString("ss", "Italic", ss, "1")
If myFont.Underline <> 0 Then .WriteAttributeString("ss", "Underline", ss, myFont.Underline.ToString)
.WriteEndElement()
Dim myInterior As Excel.Styles.Interior = m_Styles(I).Interior
.WriteStartElement("Interior")
.WriteAttributeString("ss", "Color", ss, myInterior.Color.ToString.Remove(1, 2))
.WriteAttributeString("ss", "Pattern", ss, "Solid")
.WriteEndElement()
.WriteStartElement("NumberFormat")
.WriteEndElement()
.WriteStartElement("Protection")
.WriteEndElement()
.WriteEndElement() 'Style
Next I
.WriteStartElement("Style")
.WriteAttributeString("ss", "ID", ss, "DateStyle")
.WriteStartElement("NumberFormat")
.WriteAttributeString("ss", "Format", ss, "General Date")
.WriteEndElement() 'NumberFormat
.WriteEndElement() 'Style
.WriteStartElement("Style")
.WriteAttributeString("ss", "ID", ss, "HeaderStyle")
.WriteStartElement("Font")
.WriteAttributeString("x", "Family", ss, "Swiss")
.WriteAttributeString("ss", "Bold", ss, "1")
.WriteEndElement() 'Font
.WriteEndElement() 'Style
.WriteEndElement() 'Styles
'WORKSHEETS:
.WriteStartElement("Worksheet")
.WriteAttributeString("ss", "Name", ss, "WORKSHEET")
.WriteStartElement("Table")
.WriteAttributeString("ss", "ExpandedColumnCount", ss, m_DataGrid.Columns.Count)
.WriteAttributeString("ss", "ExpandedRowCount", ss, m_DataGrid.Rows.Count + 100) 'Temporary fix: sometimes 1 row is not added.
.WriteAttributeString("ss", "FullColumns", ss, m_DataGrid.Columns.Count)
.WriteAttributeString("ss", "FullRows", ss, m_DataGrid.Rows.Count + 100) 'Temporary fix: sometimes 1 row is not added.
.WriteAttributeString("ss", "DefaultRowHeight", ss, 15)
For Each DataGridColumn In m_DataGrid.Columns
If DataGridColumn.Visibility = Visibility.Visible Then
.WriteStartElement("Column")
If TypeOf DataGridColumn Is C1.Silverlight.DataGrid.DataGridNumericColumn Then
.WriteAttributeString("ss", "AutoFitWidth", ss, 1)
ElseIf TypeOf DataGridColumn Is C1.Silverlight.DataGrid.DataGridDateTimeColumn Then
.WriteAttributeString("ss", "AutoFitWidth", ss, 1)
Else
.WriteAttributeString("ss", "AutoFitWidth", ss, 0)
End If
If DataGridColumn.Width.Value <= 100 Then
.WriteAttributeString("ss", "Width", ss, 100)
Else
.WriteAttributeString("ss", "Width", ss, DataGridColumn.Width.Value)
End If
.WriteEndElement()
End If
Next
J = 0
For Each DataGridRow In m_DataGrid.Rows
J += 1
If TypeOf DataGridRow Is GoldCRM.Controls.Filter.clsFilterRow Then
.WriteStartElement("Row")
.WriteAttributeString("ss", "Index", ss, J)
.WriteAttributeString("ss", "AutoFitHeight", ss, 0)
.WriteAttributeString("ss", "Height", ss, 15)
ColumnIndex = 0
For Each DataGridColumn In m_DataGrid.Columns
If DataGridColumn.Visibility = Visibility.Visible Then
FieldName = String.Empty
If TypeOf DataGridColumn Is DataGridBoundColumn Then
ColumnBinding = TryCast(DataGridColumn, DataGridBoundColumn).Binding
If ColumnBinding.Path IsNot Nothing Then
FieldName = ColumnBinding.Path.Path
End If
ElseIf TypeOf DataGridColumn Is DataGridTemplateColumn Then
If DataGridColumn.FilterMemberPath IsNot Nothing Then
FieldName = DataGridColumn.FilterMemberPath.Trim
End If
End If
If Not FieldName.Equals(String.Empty) Then
ColumnIndex += 1
.WriteStartElement("Cell")
.WriteAttributeString("ss", "Index", ss, ColumnIndex)
.WriteAttributeString("ss", "MergeAcross", ss, 0)
.WriteAttributeString("ss", "StyleID", ss, "HeaderStyle")
.WriteStartElement("Data")
.WriteAttributeString("ss", "Type", ss, "String")
If DataGridColumn.Header IsNot Nothing Then
.WriteValue(DataGridColumn.Header.ToString)
Else
.WriteValue("")
End If
.WriteEndElement() 'Data
.WriteEndElement() 'Cell
End If
End If
Next
.WriteEndElement() 'Row
End If
If Not (TypeOf DataGridRow Is GoldCRM.Controls.Filter.clsFilterRow) Then
.WriteStartElement("Row")
.WriteAttributeString("ss", "Index", ss, J + 1)
.WriteAttributeString("ss", "AutoFitHeight", ss, 0)
.WriteAttributeString("ss", "Height", ss, 15)
ColumnIndex = 0
For Each DataGridColumn In m_DataGrid.Columns
If DataGridColumn.Visibility = Visibility.Visible Then
FieldName = String.Empty
If TypeOf DataGridColumn Is DataGridBoundColumn Then
ColumnBinding = TryCast(DataGridColumn, DataGridBoundColumn).Binding
If ColumnBinding.Path IsNot Nothing Then
FieldName = ColumnBinding.Path.Path
End If
ElseIf TypeOf DataGridColumn Is DataGridTemplateColumn Then
If DataGridColumn.FilterMemberPath IsNot Nothing Then
FieldName = DataGridColumn.FilterMemberPath.Trim
End If
End If
If Not FieldName.Equals(String.Empty) Then
ColumnIndex += 1
Dim DataCellValue As Object = Nothing
If Not (TypeOf DataGridRow Is GoldCRM.Controls.Filter.clsFilterRow) Then
PropertyInfo = CommonUtil.GetProperty(DataGridRow.DataItem, FieldName)
If PropertyInfo IsNot Nothing Then
DataCellValue = PropertyInfo.GetValue(DataGridRow.DataItem, Nothing)
End If
End If
CellFormat = String.Empty
If DataCellValue IsNot Nothing Then
Select Case DataCellValue.GetType.Name.ToUpper
Case "BitmapImage".ToUpper
DataValue = "Image"
DataType = "String"
Case "Hyperlink".ToUpper
DataType = "String"
DataValue = "Hyperlink"
Case "Decimal".ToUpper
DataType = "Number"
DataValue = DataCellValue
Case "DateTime".ToUpper
If CType(DataCellValue, Date).Year > 1900 Then
DataType = "DateTime"
DataValue = DataCellValue
CellFormat = "DateStyle"
Else
DataType = "String"
DataValue = DataCellValue
End If
Case Else
DataType = "String"
DataValue = DataCellValue
End Select
Else
DataType = "String"
DataValue = String.Empty
End If
.WriteStartElement("Cell")
.WriteAttributeString("ss", "Index", ss, ColumnIndex)
.WriteAttributeString("ss", "MergeAcross", ss, 0)
If Not CellFormat.Equals(String.Empty) Then
.WriteAttributeString("ss", "StyleID", ss, CellFormat)
End If
.WriteStartElement("Data")
.WriteAttributeString("ss", "Type", ss, DataType)
.WriteValue(DataValue)
.WriteEndElement() 'Data
.WriteEndElement() 'Cell
End If
End If
Next
.WriteEndElement() 'Row
End If
Next
.WriteEndElement() 'Table
.WriteEndElement() 'Worksheet
.WriteEndElement() 'Workbook
.WriteEndDocument()
.Close()
End With
End Using
Catch ex As Exception
Throw New Exception(ex.Message, ex)
Finally
If m_Stream IsNot Nothing Then
m_Stream.Close()
m_Stream.Dispose()
End If
m_Stream = Nothing
m_DataGrid.IsLoading = False
DataValue = Nothing
'DataView = Nothing
'ItemsSource = Nothing
XmlSettings = Nothing
ColumnBinding = Nothing
DataGridColumn = Nothing
End Try
End Sub
Krishna

Answer 1

Hi,
i have the same issue now where i need to populate the xport file name as report name. can you send me your solution please.