Visual Studio 2012错误“不包含定义”

Question

I am new to Visual Studio 2012 and C# in general. I created a simple Windows Forms Application project with just a few labels and textboxes. I then decided to change the name of the .cs file of my application from Form1.cs to Application.cs. Now there are 3 errors on the code-generated part in the Program.cs:

Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Application());

It says that my Application does not contain a definition for any of these methods. I have not changed anything except refactored the file names. What am i missing here?

Answer 1

You're probably referencing the wrong Application class:

http://msdn.microsoft.com/en-us/library/system.windows.forms.application(v=vs.110).aspx

Use a different class name that doesn't clash or use a fully-qualified name with namespaces to disambiguate, ie:

MyProgram.AnotherNamespace.Application
System.Windows.Forms.Application

Answer 2

When you changed your Form1.cs class to Application.cs, you overwrote the default Application class, which is built into the .NET libraries. When trying to access the class using

Application.Run();

it believes you are actually trying to call the method "Run" in your defined class and not the original .NET class.

The only/best way to fix this issue is assign the created class a different name to something that does not already exist. It is the best standard to give new classes a name that is not already being used.