Troubleshooting: How to Start a Class Library Project and Fix the 'Cannot Be Started Directly' Error

When starting a class library project in Visual Studio, you may encounter an error message that says "The program '[Insert project name here]' cannot be started directly". This error message can be frustrating, especially when you're trying to get your project up and running. However, don't worry - there is a solution! In this guide, we'll walk you through the steps to start a class library project and fix the "cannot be started directly" error.

Step 1: Create a new project

The first step is to create a new project. To do this, follow these steps:

1. Open Visual Studio.
2. Click on "File" in the menu bar.
3. Click on "New" and then "Project".
4. In the "New Project" window, select "Class Library (.NET Framework)".
5. Choose a name and location for your project.
6. Click "Create".

Step 2: Set the startup project

Now that you have created a new project, you need to set it as the startup project. To do this, follow these steps:

1. Right-click on the project in the Solution Explorer.
2. Click on "Set as Startup Project".

Step 3: Build the project

Now that you have set the startup project, you need to build the project. To do this, follow these steps:

1. Click on "Build" in the menu bar.
2. Click on "Build Solution".

Step 4: Run the project

After building the project, you can now run it. To do this, follow these steps:

1. Click on "Debug" in the menu bar.
2. Click on "Start Debugging" or press F5.

Congratulations! You have successfully started a class library project and fixed the "cannot be started directly" error.

FAQ

Q1. Why am I getting the "cannot be started directly" error?

This error occurs when you try to run a class library project directly. Class library projects cannot be run directly as they do not have a user interface.

Q2. How do I know if I have a class library project?

A class library project is indicated by the ".dll" file extension. If you see a ".dll" file in your project, then you have a class library project.

Q3. Can I run a class library project as a standalone application?

No, you cannot run a class library project as a standalone application. Class library projects are meant to be used as libraries and cannot be run directly.

Q4. What is the difference between a class library project and a console application project?

A console application project is an executable program that has a user interface. A class library project, on the other hand, is a library that is meant to be used by other programs.

Q5. Can I convert a class library project to a console application project?

Yes, you can convert a class library project to a console application project by changing the project type in Visual Studio. To do this, follow these steps:

1. Right-click on the project in the Solution Explorer.
2. Click on "Properties".
3. In the "Application" tab, change the "Output Type" to "Console Application".
4. Click "OK".

Related links

• MSDN: Class Library Projects
• Stack Overflow: What is a class library project?