README

MBen.EXCLUDE_FROM_CAPTURE

Delphi Exclude your Window from Capture (Call SetWindowDisplayAffinity API)

https://github.com/user-attachments/assets/9b9c5c61-37a2-4a04-8ee2-3857334015ab

Exclude Your Delphi Window from Capture

Overview

This guide demonstrates how to exclude your Delphi VCL application window from being captured by screen recording or screenshot tools using the SetWindowDisplayAffinity API.

Key Functionality

The Windows API SetWindowDisplayAffinity allows developers to set the display affinity of a window, providing an extra layer of security by preventing screen capture. This is particularly useful for applications handling sensitive information.

Display Affinity Flags

• WDA_NONE ($0): No display affinity.
• WDA_MONITOR ($1): The window content is displayed only on a monitor.
• WDA_EXCLUDEFROMCAPTURE ($11): The window is excluded from screen capture.

Implementation in Delphi VCL

Steps:

1. Create a new VCL Forms Application.
2. Use SetWindowDisplayAffinity in the OnCreate event to apply the exclusion.

Example Code

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, Vcl.Forms;

const
  WDA_EXCLUDEFROMCAPTURE = $11;

type
  TSecureForm = class(TForm)
  protected
    procedure FormCreate(Sender: TObject);
  end;

var
  SecureForm: TSecureForm;

implementation

{$R *.dfm}

procedure TSecureForm.FormCreate(Sender: TObject);
begin
  SetWindowDisplayAffinity(Handle, WDA_EXCLUDEFROMCAPTURE);
end;

Benefits

• Protects sensitive data displayed in the window.
• Prevents unauthorized screen captures.
• Easy to implement within existing Delphi VCL projects.

Notes

• SetWindowDisplayAffinity is only effective on Windows 7 and later.
• Some advanced screen recording tools may still bypass this protection.

Demo

the video demonstration above is available showing the implementation and effect of this technique.

Feel free to contribute or raise issues in this repository if you have questions or improvements!