How to Customize Excel using VB.Net - vb.net

Question

Hello Everyone Good Morning.
I have a Program in VB.Net that will Populate Data from Mysql into the Datagridview.
I have also a button called Export and It will Export Datagridview Data in Excel Format like this.
But my our Prof. likes this Format.
How can I achieve this?
Put a Center Header
Put a .00 at the End of the Number of a Number Column
Find the Last Cell in a Column and Sum It.
I hope someone would help me.
Here is my code in Export
If DataGridView1.Rows.Count = 0 Then
MsgBox("Nothing to Export")
Else
Dim ExcelApp As Object, ExcelBook As Object
Dim ExcelSheet As Object
Dim i As Integer
Dim j As Integer
ExcelApp = CreateObject("Excel.Application")
ExcelBook = ExcelApp.WorkBooks.Add
ExcelSheet = ExcelBook.WorkSheets(1)
With ExcelSheet
For Each column As DataGridViewColumn In DataGridView1.Columns
.cells(1, column.Index + 1) = column.HeaderText
Next
For i = 1 To Me.DataGridView1.RowCount
.cells(i + 1, 1) = Me.DataGridView1.Rows(i - 1).Cells("ItemCode").Value
For j = 1 To DataGridView1.Columns.Count - 1
.cells(i + 1, j + 1) = DataGridView1.Rows(i - 1).Cells(j).Value
Next
Next
End With
ExcelApp.Visible = True
ExcelSheet = Nothing
ExcelBook = Nothing
ExcelApp = Nothing
End If

Answer 1

Try this code :
If DataGridView1.Rows.Count = 0 Then
MsgBox("Nothing to Export")
Else
Dim ExcelApp As Object, ExcelBook As Object
Dim ExcelSheet As Object
Dim i As Integer
Dim j As Integer
Dim rowIndex As Integer = 1
Dim total As Double = 0
Dim indexTotal As Integer
ExcelApp = CreateObject("Excel.Application")
ExcelBook = ExcelApp.WorkBooks.Add
ExcelSheet = ExcelBook.WorkSheets(1)
With ExcelSheet
With .Range(.Cells(rowIndex, 1), .Cells(rowIndex, DataGridView1.Columns.Count))
.HorizontalAlignment = Excel.Constants.xlCenter
.VerticalAlignment = Excel.Constants.xlCenter
.MergeCells = True
.Value = "PURCHASE REQUISITION"
.Font.Bold = True
End With
rowIndex += 2
For Each column As DataGridViewColumn In DataGridView1.Columns
.cells(rowIndex, column.Index + 1) = column.HeaderText
Next
.Range(.Cells(rowIndex, 1), .Cells(rowIndex, DataGridView1.Columns.Count)).Font.Bold = True
rowIndex += 1
For i = 0 To Me.DataGridView1.RowCount - 1
.cells(rowIndex, 1) = Me.DataGridView1.Rows(i).Cells("ItemCode").Value
For j = 1 To DataGridView1.Columns.Count - 1
If IsNumeric(DataGridView1.Rows(i).Cells(j).Value) Then
.cells(rowIndex, j + 1).NumberFormat = "#,##0.00"
.cells(rowIndex, j + 1) = DataGridView1.Rows(i).Cells(j).Value
Else
.cells(rowIndex, j + 1) = DataGridView1.Rows(i).Cells(j).Value
End If
'You can test also by index for example : if j = indexofTotalColumn then
If DataGridView1.Columns(j).Name = "Total" Then
total += DataGridView1.Rows(i).Cells(j).Value
indexTotal = j
End If
Next
rowIndex += 1
Next
.cells(rowIndex, indexTotal) = "Grand Total"
.cells(rowIndex, indexTotal + 1).NumberFormat = "#,##0.00"
.cells(rowIndex, indexTotal + 1) = total
.Range(.Cells(rowIndex, indexTotal), .Cells(rowIndex, indexTotal + 1)).Font.Bold = True
End With
ExcelApp.Visible = True
ExcelSheet = Nothing
ExcelBook = Nothing
ExcelApp = Nothing
End If