PowerRename

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PowerRename is a Windows shell extension that enables batch renaming of files using search and replace or regular expressions.

Overview

PowerRename provides a powerful and flexible way to rename files in File Explorer. It is accessible through the Windows context menu and allows users to:

• Preview changes before applying them
• Use search and replace with regular expressions
• Filter items by type (files or folders)
• Apply case-sensitive or case-insensitive matching
• Save and reuse recent search/replace patterns

Architecture

PowerRename consists of multiple components:

• Shell Extension DLL (context menu integration)
• WinUI 3 UI application
• Core renaming library

Technology Stack

• C++/WinRT
• WinUI 3
• COM for shell integration

Context Menu Integration

PowerRename integrates with the Windows context menu following the PowerToys Context Menu Handlers pattern. It uses a dual registration approach to ensure compatibility with both Windows 10 and Windows 11.

Registration Process

The context menu registration entry point is in PowerRenameExt/dllmain.cpp::enable, which registers:

• A traditional shell extension for Windows 10
• A sparse MSIX package for Windows 11 context menus

For more details on the implementation approach, see the Dual Registration section in the context menu documentation.

Code Components

dllmain.cpp

Contains the DLL entry point and module activation/deactivation code. The key function RunPowerRename is called when the context menu option is invoked, which launches the PowerRenameUI.

PowerRenameExt.cpp

Implements the shell extension COM interfaces required for context menu integration, including:

• IShellExtInit for initialization
• IContextMenu for traditional context menu support
• IExplorerCommand for Windows 11 context menu support

Helpers.cpp

Utility functions used throughout the PowerRename module, including file system operations and string manipulation.

PowerRenameItem.cpp

Represents a single item (file or folder) to be renamed. Tracks original and new names and maintains state.

PowerRenameManager.cpp

Manages the collection of items to be renamed and coordinates the rename operation.

PowerRenameRegEx.cpp

Implements the regular expression search and replace functionality used for renaming.

Settings.cpp

Manages user preferences and settings for the PowerRename module.

trace.cpp

Implements telemetry and logging functionality.

UI Implementation

PowerRename uses WinUI 3 for its user interface. The UI allows users to:

• Enter search and replace patterns
• Preview rename results in real-time
• Access previous search/replace patterns via MRU (Most Recently Used) lists
• Configure various options

Key UI Components

• Search/Replace input fields with x:Bind to SearchMRU/ReplaceMRU collections
• Preview list showing original and new filenames
• Settings panel for configuring rename options
• Event handling for SearchReplaceChanged to update the preview in real-time

Debugging

Debugging the Context Menu

See the Debugging Context Menu Handlers section for general guidance on debugging PowerToys context menu extensions.

Debugging the UI

To debug the PowerRename UI:

1. Add file paths manually in \src\modules\powerrename\PowerRenameUILib\PowerRenameXAML\App.xaml.cpp
2. Set the PowerRenameUI project as the startup project
3. Run in debug mode to test with the manually specified files

Common Issues

• Context menu not appearing: Ensure the extension is properly registered and Explorer has been restarted
• UI not launching: Check Event Viewer for errors related to WinUI 3 application activation
• Rename operations failing: Verify file permissions and check for locked files