Dev Blog

Summary ​

Conclusions ​

Windows Forms is a technology for Windows desktop applications in which the interface consists of forms and controls—objects of classes derived from Control. A net10.0-windows project contains the Program.cs entry point with the Application.Run message loop and partial form classes: the programmer's code in MainForm.cs and the form designer's code in MainForm.Designer.cs. The application is event-driven: user actions are turned into events, and handlers with the sender and e parameters run on the UI thread. Layout panels, Anchor, and Dock make a form resilient to changes in size and scaling, Validating and ErrorProvider help validate input, and menus, standard dialogs, modal forms, DataGridView with BindingList<T>, and the timer make it possible to build full-featured data applications.

Self-check questions ​

  1. Which desktop application technologies exist in .NET? How does Windows Forms differ from WPF and .NET MAUI?
  2. Why does the target framework of a Windows Forms project look like net10.0-windows? What is the UseWindowsForms property for?
  3. What does the Application.Run method do? When do the lines after it execute?
  4. Why is the form class split into the MainForm.cs and MainForm.Designer.cs files? Why must you not edit Designer.cs manually?
  5. Which Visual Studio windows are used when creating a form in the designer?
  6. Which properties do controls have in common? How does Enabled = false differ from Visible = false?
  7. In what order are the Load, Activated, Shown, FormClosing, and FormClosed events raised?
  8. How do you cancel closing a form?
  9. What is an event-driven application? What path does a mouse click take to reach a handler?
  10. What is passed in the sender and e parameters of an event handler?
  11. How do you connect one handler to several controls?
  12. How do the Anchor and Dock properties differ?
  13. What are TableLayoutPanel, FlowLayoutPanel, and SplitContainer used for?
  14. How do the Validating and Validated events work? What is the CausesValidation property for?
  15. How do you show an input error with ErrorProvider?
  16. How do you set shortcut keys for a menu item and a mnemonic for a button?
  17. How does a modal form differ from a modeless one? How do you pass data between forms?
  18. What are BindingList<T> and BindingSource for when working with DataGridView?
  19. Why is the Windows Forms timer unsuitable for precise time measurement?