Walkthrough: Call code from VBA in a Visual C# project
Applies to: Visual Studio Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
This walkthrough demonstrates how to call a method in a document-level customization for Microsoft Office Excel from Visual Basic for Applications (VBA) code in the workbook. The procedure involves three basic steps: add a method to the Sheet1
host item class, expose the method to VBA code in the workbook, and then call the method from VBA code in the workbook.
Applies to: The information in this topic applies to document-level projects for Excel and Word. For more information, see Features available by Office application and project type.
Although this walkthrough uses Excel specifically, the concepts demonstrated by the walkthrough are also applicable to document-level projects for Word.
This walkthrough illustrates the following tasks:
Creating a workbook that contains VBA code.
Trusting the location of the workbook by using the Trust Center in Excel.
Adding a method to the
Sheet1
host item class.Extracting an interface for the
Sheet1
host item class.Exposing the method to VBA code.
Calling the method from VBA code.
Note
Your computer might show different names or locations for some of the Visual Studio user interface elements in the following instructions. The Visual Studio edition that you have and the settings that you use determine these elements. For more information, see Personalize the Visual Studio IDE.
Prerequisites
You need the following components to complete this walkthrough:
An edition of Visual Studio that includes the Microsoft Office developer tools. For more information, see Configure a computer to develop Office solutions.
Microsoft Excel
Create a workbook that contains VBA code
The first step is to create a macro-enabled workbook that contains a simple VBA macro. Before you can expose code in a customization to VBA, the workbook must already contain VBA code. Otherwise, Visual Studio cannot modify the VBA project to enable VBA code to call into the customization assembly.
If you already have a workbook that contains VBA code that you want to use, you can skip this step.
To create a workbook that contains VBA code
Start Excel.
Save the active document as an Excel Macro-Enabled Workbook (*.xlsm) with the name WorkbookWithVBA. Save it to a convenient location, such as the desktop.
On the Ribbon, click the Developer tab.
Note
If the Developer tab is not visible, you must first show it. For more information, see How to: Show the developer tab on the ribbon.
In the Code group, click Visual Basic.
The Visual Basic Editor opens.
In the Project window, double-click ThisWorkbook.
The code file for the
ThisWorkbook
object opens.Add the following VBA code to the code file. This code defines a simple function that does nothing. The only purpose of this function is to ensure that a VBA project exists in the workbook. This is required for later steps in this walkthrough.
Sub EmptySub() End Sub
Save the document and exit Excel.
Create the project
Now you can create a document-level project for Excel that uses the macro-enabled workbook you created earlier.
To create a new project
Start Visual Studio.
On the File menu, point to New, and then click Project.
In the templates pane, expand Visual C#, and then expand Office/SharePoint.
Select the Office Add-ins node.
In the list of project templates, select the Excel 2010 Workbook or Excel 2013 Workbook project.
In the Name box, type CallingCodeFromVBA.
Click OK.
The Visual Studio Tools for Office Project Wizard opens.
Select Copy an existing document, and, in the Full path of the existing document box, specify the location of the WorkbookWithVBA workbook that you created earlier. If you are using your own macro-enabled workbook, specify the location of that workbook instead.
Click Finish.
Visual Studio opens the WorkbookWithVBA workbook in the designer and adds the CallingCodeFromVBA project to Solution Explorer.
Trust the location of the workbook
Before you can expose code in your solution to VBA code in the workbook, you must trust VBA in the workbook to run. There are several ways to do this. In this walkthrough, you will accomplish this task by trusting the location of the workbook in the Trust Center in Excel.
To trust the location of the workbook
Start Excel.
Click the File tab.
Click the Excel Options button.
In the categories pane, click Trust Center.
In the details pane, click Trust Center Settings.
In the categories pane, click Trusted Locations.
In the details pane, click Add new location.
In the Microsoft Office Trusted Location dialog box, browse to the folder that contains the CallingCodeFromVBA project.
Select Subfolders of this location are also trusted.
In the Microsoft Office Trusted Location dialog box, click OK.
In the Trust Center dialog box, click OK.
In the Excel Options dialog box, click OK.
Exit Excel.
Add a method to the Sheet1 class
Now that the VBA project is set up, add a public method to the Sheet1
host item class that you can call from VBA code.
To add a method to the Sheet1 class
In Solution Explorer, right-click Sheet1.cs, and then click View Code.
The Sheet1.cs file opens in the Code Editor.
Add the following code to the
Sheet1
class. TheCreateVstoNamedRange
method creates a new NamedRange object at the specified range. This method also creates an event handler for the Selected event of the NamedRange. Later in this walkthrough, you will call theCreateVstoNamedRange
method from VBA code in the document.private Microsoft.Office.Tools.Excel.NamedRange namedRange1; public void CreateVstoNamedRange(Excel.Range range, string name) { if (!this.Controls.Contains(name)) { namedRange1 = this.Controls.AddNamedRange(range, name); namedRange1.Selected += new Excel.DocEvents_SelectionChangeEventHandler( namedRange1_Selected); } else { MessageBox.Show("A named range with this specific name " + "already exists on the worksheet."); } } private void namedRange1_Selected(Microsoft.Office.Interop.Excel.Range Target) { MessageBox.Show("This named range was created by Visual Studio " + "Tools for Office."); }
Add the following method to the
Sheet1
class. This method overrides the GetAutomationObject method to return the current instance of theSheet1
class.protected override object GetAutomationObject() { return this; }
Apply the following attributes before the first line of the
Sheet1
class declaration. These attributes make the class visible to COM, but without generating a class interface.[System.Runtime.InteropServices.ComVisible(true)] [System.Runtime.InteropServices.ClassInterface( System.Runtime.InteropServices.ClassInterfaceType.None)]
Extract an interface for the Sheet1 class
Before you can expose the CreateVstoNamedRange
method to VBA code, you must create a public interface that defines this method, and you must expose this interface to COM.
To extract an interface for the Sheet1 class
In the Sheet1.cs code file, click anywhere in the
Sheet1
class.On the Refactor menu, click Extract Interface.
In the Extract Interface dialog box, in the Select public members to form interface box, click the entry for the
CreateVstoNamedRange
method.Click OK.
Visual Studio generates a new interface named
ISheet1
, and it modifies the definition of theSheet1
class so that it implements theISheet1
interface. Visual Studio also opens the ISheet1.cs file in the Code Editor.In the ISheet1.cs file, replace the
ISheet1
interface declaration with the following code. This code makes theISheet1
interface public, and it applies the ComVisibleAttribute attribute to make the interface visible to COM.[System.Runtime.InteropServices.ComVisible(true)] public interface ISheet1 { void CreateVstoNamedRange(Microsoft.Office.Interop.Excel.Range range, string name); }
Build the project.
Expose the method to VBA code
To expose the CreateVstoNamedRange
method to VBA code in the workbook, set the ReferenceAssemblyFromVbaProject property for the Sheet1
host item to True.
To expose the method to VBA code
In Solution Explorer, double-click Sheet1.cs.
The WorkbookWithVBA file opens in the designer, with Sheet1 visible.
In the Properties window, select the ReferenceAssemblyFromVbaProject property, and change the value to True.
Click OK in the message that is displayed.
Build the project.
Call the method from VBA code
You can now call the CreateVstoNamedRange
method from VBA code in the workbook.
Note
In this walkthrough, you will add VBA code to the workbook while debugging the project. The VBA code you add to this document will be overwritten the next time that you build the project, because Visual Studio replaces the document in the build output folder with a copy of the document from the main project folder. If you want to save the VBA code, you can copy it into the document in the project folder. For more information, see Combine VBA and document-level customizations.
To call the method from VBA code
Press F5 to run your project.
On the Developer tab, in the Code group, click Visual Basic.
The Visual Basic Editor opens.
On the Insert menu, click Module.
Add the following code to the new module.
This code calls the
CreateTable
method in the customization assembly. The macro accesses this method by using the globalGetManagedClass
method to access theSheet1
host item class that you exposed to VBA code. TheGetManagedClass
method was automatically generated when you set the ReferenceAssemblyFromVbaProject property earlier in this walkthrough.Sub CallVSTOMethod() Dim VSTOSheet1 As CallingCodeFromVBA.Sheet1 Set VSTOSheet1 = GetManagedClass(Sheet1) Call VSTOSheet1.CreateVstoNamedRange(Sheet1.Range("A1"), "VstoNamedRange") End Sub
Press F5.
In the open workbook, click cell A1 on Sheet1. Verify that the message box appears.
Exit Excel without saving your changes.
Next steps
You can learn more about calling code in Office solutions from VBA in these topics:
Call code in a host item in a Visual Basic customization from VBA. This process is different from the Visual C# process. For more information, see Walkthrough: Call code from VBA in a Visual Basic project.
Call code in a VSTO Add-in from VBA. For more information, see Walkthrough: Call code in a VSTO Add-in from VBA.