This project creates a WPF application which can detect system DPI, per-Monitor DPI.

Pre-requisites

• .Net Framework 4.6.2 or later

Note: Per-Monitor DPI awareness is a windows feature, it requires Windows 10 1607 and later.

How to Use

Just run the compiled executable file, it will show you:

• System DPI
• Current window DPI (for this application)
• per-Monitor DPI for every monitor

At same time, it writes output to %TEMP%\DPIMonitor.json file in below format:

{
   "CurrentWindowDpi": 96,
   "Monitors": [
      {
         "DisplayName": "\\\\.\\DISPLAY1",
         "Dpi": 96
      },
      {
         "DisplayName": "\\\\.\\DISPLAY2",
         "Dpi": 96
      }
   ],
   "SystemDpi": 96
}

You can read this file by any other programming language for your automation testing.

DPI results on the application window and the %TEMP%\DPIMonitor.json file will be updated immedately on below events:

• DPI of the screen which this application is running on changed. For example, you change the DPI from Settings manually; you drag and drop the window of this application to another screen which has different DPI.

• Window size of this application changed.

So it's also useful for manual testing.

Known Issues

Issue 1

Problem: In multi-monitor environment, if this application is running on Monitor 1, you changed DPI of Monitor 2. The DPI results will not be updated.

Workaround: Resize the window of this application or restart this application.