How to Debug a C# Class Library Project in Visual Studio?

Debugging a Class Library in Visual Studio: Resolving the "Output Type Error"

You have encountered an error while attempting to debug a downloaded C# project. The error message indicates that the project has an Output type of Class Library and cannot be started directly for debugging. This article aims to provide a solution to this issue, enabling you to delve into the project's implementation.

Understanding Class Library Projects

Class Library projects compile into Dynamic Link Libraries (.dll) assemblies, which contain a set of classes with their associated methods and properties. They do not have a main entry point, unlike executable projects that define the starting point of the program execution.

Overcoming the Error

To resolve this issue, you need to create an additional executable project within the same solution. This executable project will act as the starting point of your debugging process, referencing the Class Library project you wish to test.

Steps to Add an Executable Project:

1. Open the solution (.sln) file in Visual Studio.
2. Right-click on the solution in Solution Explorer.
3. Select "Add" -> "New Project."
4. Choose a project template (e.g., Console Application or Windows Application) with an Output Type of Console Application or Windows Application.

Setting up the Executable Project:

5. In the new executable project, create a new class and add references to the classes from the Class Library project.
6. Implement testing logic within the new class, using the classes and methods from the Class Library project.

Debug the Solution:

7. Set the executable project as the startup project.
8. Rebuild the solution.
9. Start debugging by pressing F5.

Alternative Approach:

If you do not prefer creating an additional executable project, you can use a test project. A test project allows you to create isolated unit tests to validate the functionality of the Class Library project without requiring an executable project.

Finding the Output Type:

To verify the Output Type of a project:

1. Right-click on the project in Solution Explorer.
2. Select "Properties."
3. Under the "Application" tab, you will find a dropdown labeled "Output type."

The above is the detailed content of How to Debug a C# Class Library Project in Visual Studio?. For more information, please follow other related articles on the PHP Chinese website!