Multiple Main() Method

Multiple Main() Methods

• As you know already, Main() method is nothing but the entry point of the application.
• Most commonly, a .NET application contains only one Main() method.
• If needed, you are supposed to define multiple Main() methods also.
• But,  at  run  time,  only  one  Main()  method  can  be  specified  as  ―Entry  Point‖.  This specification can be changed using the project properties.
• To understand better, we start with an example on this

Download above Code of Demo on Multiple Main() Methods : Downloads Links

• When this program is compiled, the compiler shows 2 compile time errors.

• It‘s because, two Main() methods are found in MySample  class  and  Program  class; So  that  the  compiler  can‘t  understand  which  Main()  method  is  to  be  used  as  exact entry point.
• To specify the required entry point, we have to change ―Startup Object‖ option in the project properties.
• To open the project properties, click on Project menu Properties.
• Then the project properties will be opened. Now, observe the Startup Object option.
• The Startup Object option contains two options.

           ---> (Not Set)
           ---> MultipleMainMethods.Program
                   (MultipleMainMethods‖ is the project name).

• Whenever  it  is  set  to  “(Not  Set)”,  C#  compiler  automatically  detects  the  Main() method, where it is exists. This is the default value in the ―Startup object‖ option. But this fails whenever multiple Main() methods are defined.
• Now you have to select the required class that contains the desired Main() method as entry point.

• Finally close the properties tab and come to ―Program.cs‖ tab.
• Now run the application.
• Then you can get the output from the desired Main() method