check status of DisplaySwitch.exe

montra (24)
Hi
I want to programming check DisplaySwitch.exe status . you know DispalySwitch have 4 status (internal or pc only - extend - Duplicate - second screen only).
I want show user this massage "DisplaySwitch status is (Internal or etc)"
my program must be 2 step :
step1: check status of DisplaySwitch.exe without show any thing for user
step2: show status DisplaySwitch with massage in console

this program (C++) must supported win7,8,8.1,10 (32,64bit)
thank you
whitenite1 (1785)
@montra

my program must be 2 step


So, is this supposed to be 'your' program, or ours. If it's 'yours', show us what you have, where your problems lie, etc, and we can help get 'your' program working. If it's 'ours', then you may have a long wait. Most of us probably don't have a need to write it.
montra (24)
I am not a programmer. I have a program that helps with friends like you in solving it...
I understand that I do not know anything about C ++ .
And the people in this forum are surely like you are professionals .
Surely they have different meanings with ME and OUR .
If these words had a bad meaning , I'm very sorry for you .

Dear friends like ( @Duthomhas ) helped me and I could change DisplaySwitch.exe mode with c++.
this code is :
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if (system( "displayswitch /internal" ))
  std::cout << "Failed\n";

this code solve my problem.
Last edited on
montra (24)
Now I need to detect or check four status of DisplaySwitch.exe with two step :
step1: check status of DisplaySwitch.exe without show any thing for user
step2: show status DisplaySwitch with massage in console
"DisplaySwitch status is (Internal or etc)"
Can you help me ?
Thank you so much ... (All friends of this forum)
montra (24)
is it link can help ?
https://docs.microsoft.com/en-us/windows/desktop/api/wingdi/ne-wingdi-displayconfig_topology_id
How use it ? check status of display topology
Duthomhas (13208)
Sigh.

If you are not a programmer, then why are you messing with this?


I understand that finding and using programming-related information on the internet can be overwhelming for a beginner.

The code is not all that difficult, actually.

To GET the current topology mode, you need QueryDisplayConfig().
https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-querydisplayconfig

To SET the current topology mode, you need SetDisplayConfig(), which requires Windows 7 and up (satisfying your requirements).
https://docs.microsoft.com/en-us/windows/desktop/api/winuser/nf-winuser-setdisplayconfig


Admittedly, neither article is particularly simple to read, especially for a noob. So... against my better judgement, here is a working C++ library to make using it easy, plus an example command-line program to demonstrate using it:

  display_topology.hpp 
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/*
   Copyright 2019 Michael Thomas Greer
   Distributed under the Boost Software License, Version 1.0.
   (See accompanying file LICENSE_1_0.txt or copy at
    https://www.boost.org/LICENSE_1_0.txt )
*/

#ifndef DISPLAY_TOPOLOGY_HPP
#define DISPLAY_TOPOLOGY_HPP

enum class DisplayTopology
{
  Internal,
  Clone,
  Extend,
  External,
  Error
};

DisplayTopology GetDisplayTopology();
bool            SetDisplayTopology( DisplayTopology topology );

#endif

  display_topology.cpp 
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/*
   Copyright 2019 Michael Thomas Greer
   Distributed under the Boost Software License, Version 1.0.
   (See accompanying file LICENSE_1_0.txt or copy at
    https://www.boost.org/LICENSE_1_0.txt )
*/

#include "display_topology.hpp"

#include <ciso646>
#include <windows.h>

#pragma comment( lib, "User32.lib" )

//-------------------------------------------------------------------------------------------------
DisplayTopology GetDisplayTopology()
{
  UINT32 numPathArrayElements;
  UINT32 numModeInfoArrayElements;

  GetDisplayConfigBufferSizes( QDC_DATABASE_CURRENT, &numPathArrayElements, &numModeInfoArrayElements );

  auto pathArray     = new DISPLAYCONFIG_PATH_INFO[ numPathArrayElements     ];
  auto modeInfoArray = new DISPLAYCONFIG_MODE_INFO[ numModeInfoArrayElements ];

  DISPLAYCONFIG_TOPOLOGY_ID currentTopologyId;

  auto ok = QueryDisplayConfig( QDC_DATABASE_CURRENT,
              &numPathArrayElements,     pathArray,
              &numModeInfoArrayElements, modeInfoArray,
              &currentTopologyId );

  delete [] pathArray;
  delete [] modeInfoArray;
  
  if (ok == ERROR_SUCCESS) switch (currentTopologyId)
  {
    case DISPLAYCONFIG_TOPOLOGY_INTERNAL: return DisplayTopology::Internal;
    case DISPLAYCONFIG_TOPOLOGY_CLONE:    return DisplayTopology::Clone;
    case DISPLAYCONFIG_TOPOLOGY_EXTEND:   return DisplayTopology::Extend;
    case DISPLAYCONFIG_TOPOLOGY_EXTERNAL: return DisplayTopology::External;
    default: break;
  }
  return DisplayTopology::Error;
}

//-------------------------------------------------------------------------------------------------
bool SetDisplayTopology( DisplayTopology topology )
{
  UINT32 topologies[] =
  {
    SDC_TOPOLOGY_INTERNAL,
    SDC_TOPOLOGY_CLONE,
    SDC_TOPOLOGY_EXTEND,
    SDC_TOPOLOGY_EXTERNAL
  };
  if (topology == DisplayTopology::Error) return false;
  return SetDisplayConfig( 0, NULL, 0, NULL, topologies[(int)topology] | SDC_APPLY ) == ERROR_SUCCESS;
}

  example.cpp 
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/*
   Copyright 2019 Michael Thomas Greer
   Distributed under the Boost Software License, Version 1.0.
   (See accompanying file LICENSE_1_0.txt or copy at
    https://www.boost.org/LICENSE_1_0.txt )
*/

#include <cctype>
#include <iostream>
#include <string>

#include "display_topology.hpp"

//-------------------------------------------------------------------------------------------------
void set_topology( std::string&& mode )
{
  for (auto& c : mode) c = std::tolower( c & 0x7F );
  DisplayTopology topology = 
    (mode == "internal" ) ? DisplayTopology::Internal :
    (mode == "clone"    ) ? DisplayTopology::Clone    :
    (mode == "duplicate") ? DisplayTopology::Clone    :
    (mode == "extend"   ) ? DisplayTopology::Extend   :
    (mode == "external" ) ? DisplayTopology::External :
                            DisplayTopology::Error;

  if (topology == DisplayTopology::Error) throw "Argument must be one of 'internal', 'clone', 'duplicate', 'extend', or 'external'";
  if (!SetDisplayTopology( topology ))    throw "Could not change display topology";
}

//-------------------------------------------------------------------------------------------------
void get_topology()
{
  static const char* topologies[] =
  {
    "internal",
    "clone",
    "extend",
    "external",
    nullptr
  };
  auto topology = topologies[ (int)GetDisplayTopology() ];
  if (!topology) throw "Failure to identify the current display topology";
  std::cout << topology << "\n";
}

//-------------------------------------------------------------------------------------------------
int main( int argc, char** argv )
  try
  {
    if (argc == 2) set_topology( argv[1] );
    else           get_topology();
  }
  catch (const char* error_message)
  {
    std::cerr << error_message << "\n";
    return 1;
  }

To compile with MSVC, just add all files to your project and build, or from the command line:
C:\Users\montra\programming> cl /EHsc /Ox /std:c++latest example.cpp display_topology.cpp


To comple with GCC (“g++”) or Clang (“clang++”) from the command line:
C:\Users\montra\programming> clang++ -std=c++17 -Wall -pedantic -O3 example.cpp display_topology.cpp -o example.exe


Test it with the usual:
C:\Users\montra\programming> example help
Argument must be one of 'internal', 'clone', 'duplicate', 'extend', or 'external'

C:\Users\montra\programming> example
internal

C:\Users\montra\programming> example clone

C:\Users\montra\programming> example
clone

C:\Users\montra\programming>

“Clone” and “duplicate” mean the same thing.


The example program should be enough to show you how to use the library in whatever program you are trying to create.

Your company’s legal department should not find anything objectionable about the Boost Software License. You can read more here: https://www.boost.org/users/license.html

Beware, I’m a jealous bastard. Don’t screw me over for being nice.


In the future, it is much more helpful to explain everything you want right up front, and (since it is your responsibility to learn this stuff) it helps to google around the terms you find. For example, you can google

“setdisplayconfig clone example”

Which brings up a whole list of hits https://www.google.com/search?q=setdisplayconfig+clone+example
At least one of them has working code you could have easily chosen.

Good luck!
montra (24)
Thank you dear Duthomhas

thank you :
1. You have solved many of my problems ---> (thank you so much)
2. thank you for spent time for me ---> (thank you so much)
3. you cause my career progress ---> (thank you so much)
4. and etc ---> (thank you so much)
You helped a lot and I do not know how to thank you . You are a good man


Good luck!
Last edited on
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