Partial Classes

• ASP.NET use partial class to designer and code behind, so button can found in code behind.
• A single class, struct or interface divide to multiple source code files.
• Code Generators / designers to separate with user edit to the files, clean framework
• 2 Developer can work in different source code for a single class.
• Inherit 2 Interfaces , 1 partial class handle 1 interface.
• When writing the code, it will have intellisense to not allow you to make duplicate or find the properties in this 2 files.
• At compile time , these multiple files get combined into a single class.
• Partial methods
• private and must have partial keyword.
• must void.
• implementation is optional
• can ref param but not out param