DX.DisplayInfo

A Windows console application that displays resolution and scaling information for all connected monitors.

Features

• Lists all connected monitors
• Shows current resolution for each monitor
• Displays DPI scaling percentage
• Identifies the primary monitor
• Supports modern DPI awareness (Windows 8.1+) with fallback for older systems

Requirements

• Windows Vista or later (Windows 8.1+ recommended for full DPI support)
• Delphi 10.3 or later (for compilation)

Building

Using Delphi IDE

1. Open DisplayInfo.dproj in Delphi
2. Select Build Configuration (Debug or Release)
3. Select Platform (Win32 or Win64)
4. Press F9 to compile and run, or Shift+F9 to compile only

Using Command Line

dcc32 DisplayInfo.dpr

Or for 64-bit:

dcc64 DisplayInfo.dpr

Output Structure

The project follows a clean output structure:

• Executables: Win32\Debug\ or Win32\Release\
• DCU files: Win32\Debug\dcu\ or Win32\Release\dcu\

Usage

Simply run the executable:

DisplayInfo.exe

Example Output

Monitors, Resolution and Scaling:
---
Device: \\.\DISPLAY1
Primary Monitor: Yes
Resolution (current): 3840x2160 pixels
Scaling: ~150% (DPI ~144)
---
Device: \\.\DISPLAY2
Primary Monitor: No
Resolution (current): 1920x1080 pixels
Scaling: ~100% (DPI ~96)
---
Note: 96 DPI = 100% scaling (effective DPI, if available).
Press Enter to continue...

Code Style

This project follows the Delphi Style Guide included in the repository.

Key conventions:

• 2 spaces indentation
• Local variables prefixed with L
• Parameters prefixed with A
• Global variables prefixed with G
• XML documentation comments for public APIs
• Proper error handling with try..finally blocks

Technical Details

DPI Awareness

The application uses two methods to ensure proper DPI awareness:

1. Modern (Windows 8.1+): Uses SetProcessDpiAwareness from Shcore.dll
2. Legacy (Windows Vista+): Falls back to SetProcessDPIAware from user32.dll

Monitor Information

Monitor information is retrieved using:

• EnumDisplayMonitors - Enumerates all display monitors
• GetMonitorInfo - Gets monitor information including device name and primary status
• EnumDisplaySettings - Gets current display resolution
• GetDpiForMonitor - Gets effective DPI (Windows 8.1+)
• GetDeviceCaps with LOGPIXELSX - Fallback DPI detection

License

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

Copyright (c) 2025 Olaf Monien