I built a native Windows Todo app in pure C (278 KB, no frameworks)

A modern, native Windows Todo application built with C and Win32 API. This project demonstrates advanced Windows GUI programming and system integration capabilities.

• 📝 Create, edit, and delete todo items
• ✅ Mark tasks as complete
• 💾 Persistent storage in AppData
• 🔔 System tray integration (minimize to tray)
• 🌙 Native Windows look and feel

• Written in pure C
• Uses Win32 API for GUI
• System tray integration

The application stores todos in a binary file:

• Location: %APPDATA%TodoApptodos.dat
• Format: Binary file containing the entire todo list
• Capacity: Maximum 100 todos

• Windows OS
• MinGW-w64 (GCC compiler)
• Windows SDK (included with MinGW)

1. Install MinGW-w64:

   • Download from MinGW-w64 website
   • Or use MSYS2
   • Add MinGW’s bin directory to your system PATH

2. Clone the repository:

   git clone https://github.com/Efeckc17/simple-todo-c.git
   cd simple-todo-c

3. Build the project:

   .build.bat

1. Run bin/todo.exe
2. Use the interface to:
   • Add new todos with the “Add” button
   • Edit existing todos by selecting and clicking “Edit”
   • Delete todos with the “Delete” button
   • Mark todos as complete with the “Complete” button
   • Set priority levels for each todo

.
├── src/
│   ├── main.c      # Application entry point
│   ├── todo.c      # Todo management logic
│   ├── todo.h      # Todo data structures and declarations
│   └── gui.c       # GUI implementation
├── bin/            # Compiled executable
├── build.bat       # Build script
└── README.md       # This file

The project uses the following key components:

• Win32 API: For window management and GUI
• Common Controls: For modern UI elements
• UXTheme: For Windows visual styles
• File I/O: For data persistence

This project is licensed under the MIT License – see the LICENSE file for details.

Contributions are welcome! Please feel free to submit a Pull Request.

Toxi360 – @Efeckc17

Project Link: https://github.com/Efeckc17/simple-todo-c