An Excel spreadsheet can be used in a VB.NET program. With the Microsoft.Office.Interop.Excel
assembly, we use Excel spreadsheets and data.
Some approaches yield better performance than others. It is important to use an optimized method. Add the Microsoft.Office.Interop.Excel
assembly. Go to Project and then Add Reference.
First import the Microsoft.Office.Interop.Excel
assembly. Next add the Imports statement. To use Excel, you need to create a new Application instance, and then call Workbooks.Open
.
For
-loop here.UsedRange
, which tells us the entire range that is used on the sheet.Imports Microsoft.Office.Interop.Excel Module Module1 Sub Main() ' Create new Application. Dim excel As Application = New Application ' Open Excel spreadsheet. Dim w As Workbook = excel.Workbooks.Open("C:\file.xls") ' Loop over all sheets. For i As Integer = 1 To w.Sheets.Count ' Get sheet. Dim sheet As Worksheet = w.Sheets(i) ' Get range. Dim r As Range = sheet.UsedRange ' Load all cells into 2d array. Dim array(,) As Object = r.Value(XlRangeValueDataType.xlRangeValueDefault) ' Scan the cells. If array IsNot Nothing Then Console.WriteLine("Length: {0}", array.Length) ' Get bounds of the array. Dim bound0 As Integer = array.GetUpperBound(0) Dim bound1 As Integer = array.GetUpperBound(1) Console.WriteLine("Dimension 0: {0}", bound0) Console.WriteLine("Dimension 1: {0}", bound1) ' Loop over all elements. For j As Integer = 1 To bound0 For x As Integer = 1 To bound1 Dim s1 As String = array(j, x) Console.Write(s1) Console.Write(" "c) Next Console.WriteLine() Next End If Next ' Close. w.Close() End Sub End ModuleLength: 6 Dimension 0: 3 Dimension 1: 2 1 4 2 5 3 61 4 2 5 3 6
In a deployed program, exception handling should be used around all file accesses or Excel interoperation calls. These operations are more error-prone than many other procedures.
This method minimizes the number of calls to EXCEL.EXE
by loading all the cell data in one statement. This results in a speedup over trying to individually read in cells.
Sub
Main
and use a formal parameter of the file name.Microsoft Office interoperation is tricky but makes some important tasks possible. We read in values from an existing spreadsheet in a fast way.