Visual Basic Q&A

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This article demonstrates how to create an Automation client for Microsoft Excel by using Microsoft Visual Basic .NET.
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Automation is a process that allows applications that are written in languages such as Visual Basic to programmatically control other applications. Automation to Excel allows you to perform actions such as creating a new workbook, adding data to the workbook, or creating charts. With Excel and other Microsoft Office applications, virtually all of the actions that you can perform manually through the user interface can also be performed programmatically by using Automation.
Excel exposes this programmatic functionality through an object model. The object model is a collection of classes and methods that serve as counterparts to the logical components of Excel. For example, there is an Application object, a Workbook object, and a Worksheet object, each of which contain the functionality of those components of Excel. To access the object model from Visual Basic .NET, you can set a project reference to the type library.
This article demonstrates how to set the proper project reference to the Excel type library for Visual Basic .NET and provides sample code to automate Excel. Create an automation client for Microsoft ExcelStart Microsoft Visual Studio .NET.On the File menu, click New, and then click Project. Select Windows Application from the Visual Basic Project types. Form1 is created by default.Add a reference to Microsoft Excel Object Library. To do this, follow these steps: On the Project menu, click Add Reference.On the COM tab, locate Microsoft Excel Object Library, and then click Select.
Note Microsoft Office 2003 includes Primary Interop Assemblies (PIAs). Microsoft Office XP does not include PIAs, but they can be downloaded. For more information about Office XP PIAs, click the following article number to view the article in the Microsoft Knowledge Base:
328912?(http://support.microsoft.com/kb/328912/) Microsoft Office XP primary interop assemblies (PIAs) are available for downloadClick OK in the Add References dialog box to accept your selections.On the View menu, select Toolbox to display the Toolbox, and then add a button to Form1.Double-click Button1. The code window for the form appears.In the code window, locate the following code:

Private Sub Button1_Click(ByVal sender As System.Object, _ByVal e As System.EventArgs) Handles Button1.ClickEnd Sub Replace the previous code with the following code:

Private Sub Button1_Click(ByVal sender As System.Object, _ByVal e As System.EventArgs) Handles Button1.ClickDim oXL As Excel.ApplicationDim oWB As Excel.WorkbookDim oSheet As Excel.WorksheetDim oRng As Excel.Range’ Start Excel and get Application object.oXL = CreateObject(“Excel.Application”)oXL.Visible = True’ Get a new workbook.oWB = oXL.Workbooks.AddoSheet = oWB.ActiveSheet’ Add table headers going cell by cell.oSheet.Cells(1, 1).Value = “First Name”oSheet.Cells(1, 2).Value = “Last Name”oSheet.Cells(1, 3).Value = “Full Name”oSheet.Cells(1, 4).Value = “Salary”‘ Format A1:D1 as bold, vertical alignment = center.With oSheet.Range(“A1″, “D1″).Font.Bold = True.VerticalAlignment = Excel.XlVAlign.xlVAlignCenterEnd With’ Create an array to set multiple values at once.Dim saNames(5, 2) As StringsaNames(0, 0) = “John”saNames(0, 1) = “Smith”saNames(1, 0) = “Tom”saNames(1, 1) = “Brown”saNames(2, 0) = “Sue”saNames(2, 1) = “Thomas”saNames(3, 0) = “Jane”saNames(3, 1) = “Jones”saNames(4, 0) = “Adam”saNames(4, 1) = “Johnson”‘ Fill A2:B6 with an array of values (First and Last Names).oSheet.Range(“A2″, “B6″).Value = saNames’ Fill C2:C6 with a relative formula (=A2 & ” ” & B2).oRng = oSheet.Range(“C2″, “C6″)oRng.Formula = “=A2 & “” “” & B2″‘ Fill D2:D6 with a formula(=RAND()*100000) and apply format.oRng = oSheet.Range(“D2″, “D6″)oRng.Formula = “=RAND()*100000″oRng.NumberFormat = “$0.00″‘ AutoFit columns A:D.oRng = oSheet.Range(“A1″, “D1″)oRng.EntireColumn.AutoFit()’ Manipulate a variable number of columns for Quarterly Sales Data.Call DisplayQuarterlySales(oSheet)’ Make sure Excel is visible and give the user control’ of Excel’s lifetime.oXL.Visible = TrueoXL.UserControl = True’ Make sure that you release object references.oRng = NothingoSheet = NothingoWB = NothingoXL.Quit()oXL = NothingExit SubErr_Handler:MsgBox(Err.Description, vbCritical, “Error: ” & Err.Number)End SubPrivate Sub DisplayQuarterlySales(ByVal oWS As Excel.Worksheet)Dim oResizeRange As Excel.RangeDim oChart As Excel.ChartDim oSeries As Excel.SeriesDim iNumQtrs As IntegerDim sMsg As StringDim iRet As Integer’ Determine how many quarters to display data for.For iNumQtrs = 4 To 2 Step -1sMsg = “Enter sales data for” & Str(iNumQtrs) & ” quarter(s)?”iRet = MsgBox(sMsg, vbYesNo Or vbQuestion _Or vbMsgBoxSetForeground, “Quarterly Sales”)If iRet = vbYes Then Exit ForNext iNumQtrs’ Starting at E1, fill headers for the number of columns selected.oResizeRange = oWS.Range(“E1″, “E1″).Resize(ColumnSize:=iNumQtrs)oResizeRange.Formula = “=”"Q”" & COLUMN()-4 & CHAR(10) & “”Sales”"”‘ Change the Orientation and WrapText properties for the headers.oResizeRange.Orientation = 38oResizeRange.WrapText = True’ Fill the interior color of the headers.oResizeRange.Interior.ColorIndex = 36′ Fill the columns with a formula and apply a number format.oResizeRange = oWS.Range(“E2″, “E6″).Resize(ColumnSize:=iNumQtrs)oResizeRange.Formula = “=RAND()*100″oResizeRange.NumberFormat = “$0.00″‘ Apply borders to the Sales data and headers.oResizeRange = oWS.Range(“E1″, “E6″).Resize(ColumnSize:=iNumQtrs)oResizeRange.Borders.Weight = Excel.XlBorderWeight.xlThin’ Add a Totals formula for the sales data and apply a border.oResizeRange = oWS.Range(“E8″, “E8″).Resize(ColumnSize:=iNumQtrs)oResizeRange.Formula = “=SUM(E2:E6)”With oResizeRange.Borders(Excel.XlBordersIndex.xlEdgeBottom).LineStyle = Excel.XlLineStyle.xlDouble.Weight = Excel.XlBorderWeight.xlThickEnd With’ Add a Chart for the selected data.oResizeRange = oWS.Range(“E2:E6″).Resize(ColumnSize:=iNumQtrs)oChart = oWS.Parent.Charts.AddWith oChart.ChartWizard(oResizeRange, Excel.XlChartType.xl3DColumn, , Excel.XlRowCol.xlColumns)oSeries = .SeriesCollection(1)oSeries.XValues = oWS.Range(“A2″, “A6″)For iRet = 1 To iNumQtrs.SeriesCollection(iRet).Name = “=”"Q” & Str(iRet) & “”"”Next iRet.Location(Excel.XlChartLocation.xlLocationAsObject, oWS.Name)End With’ Move the chart so as not to cover your data.With oWS.Shapes.Item(“Chart 1″).Top = oWS.Rows(10).Top.Left = oWS.Columns(2).LeftEnd With’ Free any references.oChart = NothingoResizeRange = NothingEnd Sub Add the following code to the top of Form1.vb:

Imports Microsoft.Office.Core Test the automation clientPress F5 to build and to run the program.On the form, click Button1. The program starts Excel and populates data on a new worksheet.When you are prompted to enter quarterly sales data, click Yes. A chart that is linked to quarterly data is added to the worksheet.

Symptoms
This article demonstrates how to create and manipulate Excel by using Automation from Visual Basic.
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There are two ways to control an Automation server: by using either late binding or early binding. With late binding, methods are not bound until run-time and the Automation server is declared as Object. With early binding, your application knows at design-time the exact type of object it will be communicating with, and can declare its objects as a specific type. This sample uses early binding, which is considered better in most cases because it affords greater performance and better type safety.
To early bind to an Automation server, you need to set a reference to that server’s type library. In Visual Basic, this is done through the References dialog box found under the Project | References menu. For this sample, you will need to add a reference to the type library for Excel before you can run the code. See the steps below on how to add the reference.

Building the Automation SampleStart Visual Basic and create a new Standard EXE project. Form1 is created by default.ClickProject and then click References. The References dialog box appears. Scroll down the list until you find Microsoft Excel object library, and then select the item to add a reference to Excel. If the correct object library for your version of Excel does not appear in the list, make sure that you have your version of Excel properly installed.
NotesIf you are automating Microsoft Office Excel 2007, the type library appears as Microsoft Excel 12.0 Object Library in the References list.If you are automating Microsoft Office Excel 2003, the type library appears as Microsoft Excel 11.0 Object Library in the References list.If you are automating Microsoft Excel 2002, the type library appears as Microsoft Excel 10.0 Object Library in the References listIf you are automating Microsoft Excel 2000, the type library appears as Microsoft Excel 9.0 Object Library in the References list.If you are automating Microsoft Excel 97, the type library appears as Microsoft Excel 8.0 Object Library in the References listClick OK to close the References dialog box.Add a CommandButton to Form1.In the code window for Form1, insert the following code:

Option ExplicitPrivate Sub Command1_Click()Dim oXL As Excel.ApplicationDim oWB As Excel.WorkbookDim oSheet As Excel.WorksheetDim oRng As Excel.Range’On Error GoTo Err_Handler’ Start Excel and get Application object.Set oXL = CreateObject(“Excel.Application”)oXL.Visible = True’ Get a new workbook.Set oWB = oXL.Workbooks.AddSet oSheet = oWB.ActiveSheet’ Add table headers going cell by cell.oSheet.Cells(1, 1).Value = “First Name”oSheet.Cells(1, 2).Value = “Last Name”oSheet.Cells(1, 3).Value = “Full Name”oSheet.Cells(1, 4).Value = “Salary”‘ Format A1:D1 as bold, vertical alignment = center.With oSheet.Range(“A1″, “D1″).Font.Bold = True.VerticalAlignment = xlVAlignCenterEnd With’ Create an array to set multiple values at once.Dim saNames(5, 2) As StringsaNames(0, 0) = “John”saNames(0, 1) = “Smith”saNames(1, 0) = “Tom”saNames(1, 1) = “Brown”saNames(2, 0) = “Sue”saNames(2, 1) = “Thomas”saNames(3, 0) = “Jane”saNames(3, 1) = “Jones”saNames(4, 0) = “Adam”saNames(4, 1) = “Johnson”‘ Fill A2:B6 with an array of values (First and Last Names).oSheet.Range(“A2″, “B6″).Value = saNames’ Fill C2:C6 with a relative formula (=A2 & ” ” & B2).Set oRng = oSheet.Range(“C2″, “C6″)oRng.Formula = “=A2 & “” “” & B2″‘ Fill D2:D6 with a formula(=RAND()*100000) and apply format.Set oRng = oSheet.Range(“D2″, “D6″)oRng.Formula = “=RAND()*100000″oRng.NumberFormat = “$0.00″‘ AutoFit columns A:D.Set oRng = oSheet.Range(“A1″, “D1″)oRng.EntireColumn.AutoFit’ Manipulate a variable number of columns for Quarterly Sales Data.Call DisplayQuarterlySales(oSheet)’ Make sure Excel is visible and give the user control’ of Microsoft Excel’s lifetime.oXL.Visible = TrueoXL.UserControl = True’ Make sure you release object references.Set oRng = NothingSet oSheet = NothingSet oWB = NothingSet oXL = NothingExit SubErr_Handler:MsgBox Err.Description, vbCritical, “Error: ” & Err.NumberEnd SubPrivate Sub DisplayQuarterlySales(oWS As Excel.Worksheet)Dim oResizeRange As Excel.RangeDim oChart As Excel.ChartDim iNumQtrs As IntegerDim sMsg As StringDim iRet As Integer’ Determine how many quarters to display data for.For iNumQtrs = 4 To 2 Step -1sMsg = “Enter sales data for” & Str(iNumQtrs) & ” quarter(s)?”iRet = MsgBox(sMsg, vbYesNo Or vbQuestion _Or vbMsgBoxSetForeground, “Quarterly Sales”)If iRet = vbYes Then Exit ForNext iNumQtrssMsg = “Displaying data for” & Str(iNumQtrs) & ” quarter(s).”MsgBox sMsg, vbMsgBoxSetForeground, “Quarterly Sales”‘ Starting at E1, fill headers for the number of columns selected.Set oResizeRange = oWS.Range(“E1″, “E1″).Resize(ColumnSize:=iNumQtrs)oResizeRange.Formula = “=”"Q”" & COLUMN()-4 & CHAR(10) & “”Sales”"”‘ Change the Orientation and WrapText properties for the headers.oResizeRange.Orientation = 38oResizeRange.WrapText = True’ Fill the interior color of the headers.oResizeRange.Interior.ColorIndex = 36′ Fill the columns with a formula and apply a number format.Set oResizeRange = oWS.Range(“E2″, “E6″).Resize(ColumnSize:=iNumQtrs)oResizeRange.Formula = “=RAND()*100″oResizeRange.NumberFormat = “$0.00″‘ Apply borders to the Sales data and headers.Set oResizeRange = oWS.Range(“E1″, “E6″).Resize(ColumnSize:=iNumQtrs)oResizeRange.Borders.Weight = xlThin’ Add a Totals formula for the sales data and apply a border.Set oResizeRange = oWS.Range(“E8″, “E8″).Resize(ColumnSize:=iNumQtrs)oResizeRange.Formula = “=SUM(E2:E6)”With oResizeRange.Borders(xlEdgeBottom).LineStyle = xlDouble.Weight = xlThickEnd With’ Add a Chart for the selected dataSet oResizeRange = oWS.Range(“E2:E6″).Resize(ColumnSize:=iNumQtrs)Set oChart = oWS.Parent.Charts.AddWith oChart.ChartWizard oResizeRange, xl3DColumn, , xlColumns.SeriesCollection(1).XValues = oWS.Range(“A2″, “A6″)For iRet = 1 To iNumQtrs.SeriesCollection(iRet).Name = “=”"Q” & Str(iRet) & “”"”Next iRet.Location xlLocationAsObject, oWS.NameEnd With’ Move the chart so as not to cover your data.With oWS.Shapes(“Chart 1″).Top = oWS.Rows(10).Top.Left = oWS.Columns(2).LeftEnd With’ Free any references.Set oChart = NothingSet oResizeRange = NothingEnd Sub Press F5 to run the project.