Walkthrough: Compile a C++/CLI program that targets the CLR in Visual Studio

Artikkeli
10/29/2021

By using C++/CLI you can create C++ programs that use .NET classes as well as native C++ types. C++/CLI is intended for use in console applications and in DLLs that wrap native C++ code and make it accessible from .NET programs. To create a Windows user interface based on .NET, use C# or Visual Basic.

For this procedure, you can type your own C++ program or use one of the sample programs. The sample program that we use in this procedure creates a text file named textfile.txt, and saves it to the project directory.

Prerequisites

An understanding of the fundamentals of the C++ language.
In Visual Studio 2017 and later, C++/CLI support is an optional component. To install it, open the Visual Studio Installer from the Windows Start menu. Make sure that the Desktop development with C++ tile is checked, and in the Optional components section, also check C++/CLI Support.

Create a new project

The following steps vary depending on which version of Visual Studio you are using. To see the documentation for your preferred version of Visual Studio, use the Version selector control. It's found at the top of the table of contents on this page.

To create a C++/CLI project in Visual Studio

In Solution Explorer, right-click on the top to open the Create a New Project dialog box.
At the top of the dialog, type CLR in the search box and then choose CLR Empty Project (.NET Framework) from the results list.
Choose the Create button to create the project.

To create a C++/CLI project in Visual Studio 2017

Create a new project. On the File menu, point to New, and then click Project.
From the Visual C++ project types, click CLR, and then click CLR Empty Project.
Type a project name. By default, the solution that contains the project has the same name as the new project, but you can enter a different name. You can enter a different location for the project if you want.
Click OK to create the new project.

To create a C++/CLI project in Visual Studio 2015

Create a new project. On the File menu, point to New, and then click Project.
From the Visual C++ project types, click CLR, and then click CLR Empty Project.
Type a project name. By default, the solution that contains the project has the same name as the new project, but you can enter a different name. You can enter a different location for the project if you want.
Click OK to create the new project.

Add a source file

If Solution Explorer isn't visible, click Solution Explorer on the View menu.
Add a new source file to the project:
- Right-click the Source Files folder in Solution Explorer, point to Add, and click New Item.
- Click C++ File (.cpp) and type a file name and then click Add.
The .cpp file appears in the Source Files folder in Solution Explorer and a tabbed window appears where you type the code you want in that file.
Click in the newly created tab in Visual Studio and type a valid Visual C++ program, or copy and paste one of the sample programs.

For example, you can use the How to: Write a Text File (C++/CLI) sample program (in the File Handling and I/O node of the Programming Guide).

If you use the sample program, notice that you use the gcnew keyword instead of new when creating a .NET object, and that gcnew returns a handle (^) rather than a pointer (*):

StreamWriter^ sw = gcnew StreamWriter(fileName);

For more information on C++/CLI syntax, see Component Extensions for Runtime Platforms.
On the Build menu, click Build Solution.

The Output window displays information about the compilation progress, such as the location of the build log and a message that indicates the build status.

If you make changes and run the program without doing a build, a dialog box might indicate that the project is out of date. Select the checkbox on this dialog before you click OK if you want Visual Studio to always use the current versions of files instead of prompting you each time it builds the application.
On the Debug menu, click Start without Debugging.
If you used the sample program, when you run the program a command window is displayed that indicates the text file has been created.

The textfile.txt text file is now located in your project directory. You can open this file by using Notepad.

Note

Choosing the empty CLR project template automatically set the /clr compiler option. To verify this, right-click the project in Solution Explorer and clicking Properties, and then check the Common Language Runtime support option in the General node of Configuration Properties.

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