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Giving focus to an external application (Chrome)

Good morning,
I'm trying to figure out how to put the focus on Google Chrome. That is to say to make as a click on the software in the taskbar (already open).
Thank you for helping me to put the focus on Google Chrome.

You can use the following function to bring chrome to front and to focus it.
The code uses 2 windows API calls because what you need is not directly provided by the .Net framework.
using System;
using System.Runtime.InteropServices;
using System.Diagnostics;
public class Program
{
[DllImport("user32.dll")]
[return: MarshalAs(System.Runtime.InteropServices.UnmanagedType.Bool)]
private static extern bool ShowWindow(IntPtr hWnd, int flags);
[DllImport("user32.dll")]
public static extern int SetForegroundWindow(IntPtr hwnd);
private static bool FocusChromeWindow()
{
foreach (Process chrome in Process.GetProcessesByName("chrome"))
{
// In case the process did not reveal a main window handle
// try to restore it in case it is hidden
if (chrome.MainWindowHandle == IntPtr.Zero)
{
ShowWindow(chrome.Handle, 9); // 9 = Restore
}
// If main window handle is still zero,
// this chrome process is one of the background
// workers chrome starts. Skip it.
if (chrome.MainWindowHandle != IntPtr.Zero)
{
SetForegroundWindow(chrome.MainWindowHandle);
return true;
}
}
return false;
}
static void Main(string[] args)
{
FocusChromeWindow();
Console.ReadLine();
}
}

Run the current application as Single Instance and show the previous instance

I just implemented this code that is guarding the Single Instance of the Application, in order to not run the application twice.
Now I am wondering how I can show the original Application process that is already running.
Here is my code in the program class:
static class Program
{
[STAThread]
static void Main()
{
const string appName = "MyappName";
bool createdNew;
mutex = new Mutex(true, appName, out createdNew);
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Form form = new Form1();
if (!createdNew)
{
form.Show(); <<=========================== NOT WORKING
form.Visible = true; <<===================== None
form.TopMost = true; <<===================== of
form.BringToFront(); <<===================== these working!
form.WindowState = FormWindowState.Maximized;
return;
}
Application.Run(form);
} private static Mutex mutex = null;
}

I propose you a different method, using a combination of the System.Threading.Mutex class and UIAutomation AutomationElement class.
A Mutex can be, as you already know, a simple string. You can assign an application a Mutex in the form of a GUID, but it can be anything else.
Let's assume this is the current Application Mutex:
string ApplicationMutex = "BcFFcd23-3456-6543-Fc44abcd1234";
//Or
string ApplicationMutex = "Global\BcFFcd23-3456-6543-Fc44abcd1234";
Note:
Use the "Global\" Prefix to define the scope of the Mutex. If no prefix is specified, the "Local\" prefix is assumed and used instead. This will prevent a single instance of the process when multiple desktops are active or Terminal Services is running on the server.
If we want to verify whether another running Process has already registered the same Mutex, we try to register our Mutex and if it fails, another instance of our Application is already running.
We let the user know that the Application supports only a single instance, then switch to the running process, showing its interface and finally exit the duplicate Application, disposing of the Mutex.
The method to activate a previous instance of the Application may vary based on the type of the Application, but only some details change.
We can use Process..GetProcesses() to retrieve a list of the running processes and verify if one of them has the same details as ours.
Here, you have a windowed Application (it has an UI), so it's already possible to filter the list, excluding those processes that do not have a MainWindowHandle.
Process[] windowedProcesses =
Process.GetProcesses().Where(p => p.MainWindowHandle != IntPtr.Zero).ToArray();
To identify the right one, we could test if the Process.ProcessName is the same.
But this name is tied to the executable name. If the file name changes (someone changes it for some reason), we will never identify the Process this way.
One possible way to identify the right Process is to test the Process.MainModule.FileVersionInfo.ProductName and check whether it's the same.
When found, it's possible to bring the original Application to front with an AutomationElement created using the MainWindowHandle of the identified Process.
The AutomationElement can automate different Patterns (sort of controls that provide automation functionalities for UI elements).
A WindowPattern allows to control a window-base control (the Platform is irrelevant, could be a WinForms' Form or a WPF's Window).
AutomationElement element = AutomationElement.FromHandle(process.MainWindowHandle);
WindowPattern wPattern = element.GetCurrentPattern(WindowPattern.Pattern) as WindowPattern;
wPattern.SetWindowVisualState(WindowVisualState.Normal);
To use the UIAutomation functionalities, you have to add these refereneces in your Project:
- UIAutomationClient
- UIAutomationTypes
UPDATE:
Since the Application's Form might be hidden, Process.GetProcesses() will not find it's Window handle, thus AutomationElement.FromHandle() cannot be used to identify the Form Window.
A possible workaround, without dismissing the UIAutomation "pattern", is to register an Automation event, using Automation.AddAutomationEventHandler, which allows to receive a notification when an UI Automation events occurs, such as a new Window is about to be shown (a Program is run).
The event is registerd only if the Application needs to run as Single Instance. When the event is raised, the new Process AutomationElement Name (the Windows Title Text) is compared to the current and, if it's the same, the hidden Form will un-hide and show itself in Normal state.
As a fail-safe measure, we present an information MessageBox. The MessageBox caption has the same caption as the Application MainForm.
(Tested with a Form with its WindowsState set to Minimized and its Visible property set to false).
After the orginal Process has been brought to front, we just neeed to close the current thread and release the resources we created (mainly the Mutex, in this case).
using System;
using System.Diagnostics;
using System.Linq;
using System.Threading;
using System.Windows.Automation;
using System.Windows.Forms;
static class Program
{
static Mutex mutex = null;
[STAThread]
static void Main()
{
Application.ThreadExit += ThreadOnExit;
string applicationMutex = #"Global\BcFFcd23-3456-6543-Fc44abcd1234";
mutex = new Mutex(true, applicationMutex);
bool singleInstance = mutex.WaitOne(0, false);
if (!singleInstance)
{
string appProductName = Process.GetCurrentProcess().MainModule.FileVersionInfo.ProductName;
Process[] windowedProcesses =
Process.GetProcesses().Where(p => p.MainWindowHandle != IntPtr.Zero).ToArray();
foreach (Process process in windowedProcesses.Where(p => p.MainModule.FileVersionInfo.ProductName == appProductName))
{
if (process.Id != Process.GetCurrentProcess().Id)
{
AutomationElement wElement = AutomationElement.FromHandle(process.MainWindowHandle);
if (wElement.Current.IsOffscreen)
{
WindowPattern wPattern = wElement.GetCurrentPattern(WindowPattern.Pattern) as WindowPattern;
#if DEBUG
WindowInteractionState state = wPattern.Current.WindowInteractionState;
Debug.Assert(!(state == WindowInteractionState.NotResponding), "The application is not responding");
Debug.Assert(!(state == WindowInteractionState.BlockedByModalWindow), "Main Window blocked by a Modal Window");
#endif
wPattern.SetWindowVisualState(WindowVisualState.Normal);
break;
}
}
}
Thread.Sleep(200);
MessageBox.Show("Application already running", "MyApplicationName",
MessageBoxButtons.OK, MessageBoxIcon.Information,
MessageBoxDefaultButton.Button1, MessageBoxOptions.ServiceNotification);
}
if (SingleInstance) {
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new MyAppMainForm());
}
else {
Application.ExitThread();
}
}
private static void ThreadOnExit(object s, EventArgs e)
{
mutex.Dispose();
Application.ThreadExit -= ThreadOnExit;
Application.Exit();
}
}
In the Application MainForm constructor:
(this is used in case the Application's Main Window is hidden when a new instance is run, hence the procedure in Program.cs cannot find its handle)
public partial class MyAppMainForm : Form
{
public MyAppMainForm()
{
InitializeComponent();
Automation.AddAutomationEventHandler(WindowPattern.WindowOpenedEvent,
AutomationElement.RootElement,
TreeScope.Subtree, (uiElm, evt) =>
{
AutomationElement element = uiElm as AutomationElement;
string windowText = element.Current.Name;
if (element.Current.ProcessId != Process.GetCurrentProcess().Id && windowText == this.Text)
{
this.BeginInvoke(new MethodInvoker(() =>
{
this.WindowState = FormWindowState.Normal;
this.Show();
}));
}
});
}
}

Run Only One time :
static class Program
{
[STAThread]
static void Main()
{
bool createdNew = true;
using (Mutex mutex = new Mutex(true, "samplename", out createdNew))
{
if (createdNew)
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.ThreadException += new ThreadExceptionEventHandler(Application_ThreadException);
AppDomain.CurrentDomain.UnhandledException += new UnhandledExceptionEventHandler(CurrentDomain_UnhandledException);
Application.Run(new Form1());
}
else
{
ProcessUtils.SetFocusToPreviousInstance("samplename");
}
}
}
private static void CurrentDomain_UnhandledException(object sender, UnhandledExceptionEventArgs e)
{
}
private static void Application_ThreadException(object sender, ThreadExceptionEventArgs e)
{
}
}
ProcessUtils :
public static class ProcessUtils
{
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool SetForegroundWindow(IntPtr hWnd);
[DllImport("user32.dll")]
static extern bool IsIconic(IntPtr hWnd);
[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
const int SW_RESTORE = 9;
[DllImport("user32.dll")]
static extern IntPtr GetLastActivePopup(IntPtr hWnd);
[DllImport("user32.dll")]
static extern bool IsWindowEnabled(IntPtr hWnd);
public static void SetFocusToPreviousInstance(string windowCaption)
{
IntPtr hWnd = FindWindow(null, windowCaption);
if (hWnd != null)
{
IntPtr hPopupWnd = GetLastActivePopup(hWnd);
if (hPopupWnd != null && IsWindowEnabled(hPopupWnd))
{
hWnd = hPopupWnd;
}
SetForegroundWindow(hWnd);
if (IsIconic(hWnd))
{
ShowWindow(hWnd, SW_RESTORE);
}
}
}
}
Normal Run :
static class Program
{
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}

If you are still looking for an answer. There is a good example here that
uses windows messages to restore the previous instance. It work even if the first instance is minimized contrary to FindWindow witch does not work in that case.

Hide the console window from a console application [duplicate]

This question already has answers here:
Show/Hide the console window of a C# console application
(9 answers)
Closed 7 years ago.
I have an application that was using the console, but I changed all the code to write to a file instead of the console. I would now like the console to stop appearing when I run the application. How do I do this? I do not know what is opening the console in the first place, even though nothing is being written to it in the code.
I have looked in the applications references and cannot find System.Console being referenced. I though disabling that would fix it or point me in the right direction with errors. I am not sure where else to look.
All the other things I found online talk about making the console hidden. I would like it to not appear in the first place.

Go to the Application Properties and change Output Type from Console Application to Windows Application.
Or you can do it using a code below
using System.Runtime.InteropServices;
[DllImport("kernel32.dll")]
static extern IntPtr GetConsoleWindow();
[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
And in main
const int SW_HIDE = 0;
const int SW_SHOW = 5;
var handle = GetConsoleWindow();
ShowWindow(handle, SW_HIDE); // To hide
ShowWindow(handle, SW_SHOW); // To show
Also, you can run you application as a service. In order to do this you should create a service - File->New Project->Visual C#->Windows->Windows Service. Then create a public method StartWork() and add all you logic there. And call this method in OnStart().
protected override void OnStart(string[] args)
{
try
{
this.StartJobs();
}
catch (Exception ex)
{
// catching exception
}
}
public void StartWork()
{
// all the logic here
}
In main you should create this service and use System.ServiceProcess.ServiceBase.Run() to run it as service or call StartWork() to run it as console application.
static void Main(string[] args)
{
TestService = new TestService ();
#if DEBUG
TestService.StartWork()();
#else
System.ServiceProcess.ServiceBase.Run(TestService );
#endif
}

how to detect a new application being launched from C#?

I have a .dll library for c# that loves to pop out a 'Welcome' screen when it starts.
This screen appears as an application in the task manager.
Is there some way to automatically detect this application/form being launched and close it?
Thanks! :)

Here us simple console application that will monitor and close specified window
class Program
{
static void Main(string[] args)
{
while(true)
{
FindAndKill("Welcome");
Thread.Sleep(1000);
}
}
private static void FindAndKill(string caption)
{
Process[] processes = Process.GetProcesses();
foreach (Process p in processes)
{
IntPtr pFoundWindow = p.MainWindowHandle;
StringBuilder windowText = new StringBuilder(256);
GetWindowText(pFoundWindow, windowText, windowText.Capacity);
if (windowText.ToString() == caption)
{
p.CloseMainWindow();
Console.WriteLine("Excellent kill !!!");
}
}
}
[DllImport("user32.dll", EntryPoint = "GetWindowText",ExactSpelling = false, CharSet = CharSet.Auto, SetLastError = true)]
private static extern int GetWindowText(IntPtr hWnd,StringBuilder lpWindowText, int nMaxCount);
}

If it's running within your process and opening a Form (not a Dialog), you can use something like this to close all Forms which aren't opened by your own Assembly.
foreach (Form form in Application.OpenForms)
if (form.GetType().Assembly != typeof(Program).Assembly)
form.Close();
What is your own Assembly is defined by the class Program, you could also use Assembly.GetExecutingAssembly or Assembly.GetCallingAssembly, but I'm not sure it will behave correctly, if you run the Application inside Visual Studio (since it might return the VS Assembly).

Activating the main form of a single instance application

In a C# Windows Forms application I want to detect if another instance of the application is already running.
If so, activate the main form of the running instance and exit this instance.
What is the best way to achieve this?

Scott Hanselman answers on you question in details.

Here is what I'm currently doing in the application's Program.cs file.
// Sets the window to be foreground
[DllImport("User32")]
private static extern int SetForegroundWindow(IntPtr hwnd);
// Activate or minimize a window
[DllImportAttribute("User32.DLL")]
private static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
private const int SW_RESTORE = 9;
static void Main()
{
try
{
// If another instance is already running, activate it and exit
Process currentProc = Process.GetCurrentProcess();
foreach (Process proc in Process.GetProcessesByName(currentProc.ProcessName))
{
if (proc.Id != currentProc.Id)
{
ShowWindow(proc.MainWindowHandle, SW_RESTORE);
SetForegroundWindow(proc.MainWindowHandle);
return; // Exit application
}
}
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new MainForm());
}
catch (Exception ex)
{
}
}

You can use such detection and activate your instance after it:
// Detect existing instances
string processName = Process.GetCurrentProcess().ProcessName;
Process[] instances = Process.GetProcessesByName(processName);
if (instances.Length > 1)
{
MessageBox.Show("Only one running instance of application is allowed");
Process.GetCurrentProcess().Kill();
return;
}
// End of detection

Aku, that is a good resource. I answered a question similar to this one a while back. You can check my answer here. Even though this was for WPF, you can use the same logic in WinForms.