Can anyone provide me an example of how to use WM_CLOSE to close a small application like Notepad?
Provided you already have a handle to send to.
...Some Class...
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
//I'd double check this constant, just in case
static uint WM_CLOSE = 0x10;
public void CloseWindow(IntPtr hWindow)
{
SendMessage(hWindow, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
}
...Continue Class...
Getting a handle can be tricky. Control descendant classes (WinForms, basically) have Handle's, and you can enumerate all top-level windows with EnumWindows (which requires more advanced p/invoke, though only slightly).
Suppose you want to close notepad. the following code will do it:
private void CloseNotepad(){
string proc = "NOTEPAD";
Process[] processes = Process.GetProcesses();
var pc = from p in processes
where p.ProcessName.ToUpper().Contains(proc)
select p;
foreach (var item in pc)
{
item.CloseMainWindow();
}
}
Considerations:
If the notepad has some unsaved text it will popup "Do you want to save....?" dialog or if the process has no UI it throws following exception
'item.CloseMainWindow()' threw an exception of type
'System.InvalidOperationException' base {System.SystemException}:
{"No process is associated with this object."}
If you want to force close process immediately please replace
item.CloseMainWindow()
with
item.Kill();
If you want to go PInvoke way you can use handle from selected item.
item.Handle; //this will return IntPtr object containing handle of process.
Related
I want to display a tiff file using shell execute. I am assuming the default app is the photoviewer. My Problem is that when i want to kill the process with photoviewer.Kill() i get an System.InvalidOperationException. When setting a breakpoint after photoViewer.Start() i realised that photoviewer does not conatain an Id.
I there a sufficent way to kill it? As it runs via dllhost.exe i do not want to retrun all processes named dllhost and kill them all since i do not know what else is run by dllhost.
Process photoViewer = new Process();
private void StartProcessUsingShellExecute(string filePath)
{
photoViewer.StartInfo = new ProcessStartInfo(filePath);
photoViewer.StartInfo.UseShellExecute = true;
photoViewer.Start();
}
I have another approach without shell execute but this approach seems to have dpi issues.
Approach without shell execute
Found a solution, may help anyone with a similar problem.
When i looked into the task manager i found that the windows 10 photoviewer runs detached from the application via dllhost. So since i have 4 dllhost processes up and running and just want to close the window. I do:
private void StartProcessAsShellExecute(string filePath)
{
photoViewer.StartInfo = new ProcessStartInfo(filePath);
photoViewer.StartInfo.UseShellExecute = true;
photoViewer.Start();
Process[] processes = Process.GetProcessesByName("dllhost");
foreach (Process p in processes)
{
IntPtr windowHandle = p.MainWindowHandle;
CloseWindow(windowHandle);
// do something with windowHandle
}
viewerOpen = true;
}
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = false)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
//I'd double check this constant, just in case
static uint WM_CLOSE = 0x10;
public void CloseWindow(IntPtr hWindow)
{
SendMessage(hWindow, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
}
that closes all dllhost windows (of which i have just 1, the photoviewer)
I've tried searching but nothing really matches my demand.
I don't want explorer.exe to be terminated or restarted.
I just want any open explorer windows to close.
[DllImport("user32.dll")]
private static extern bool EnumWindows(EnumWindowsDelegate lpEnumFunc, IntPtr lParam);
[DllImport("user32.dll")]
private static extern IntPtr GetWindowThreadProcessId(IntPtr hWnd, out IntPtr lpdwProcessId);
[DllImport("user32.dll")]
private static extern uint RealGetWindowClass(IntPtr hwnd, StringBuilder pszType, uint cchType);
[DllImport("user32.dll")]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
static uint WM_CLOSE = 0x10;
private delegate bool EnumWindowsDelegate(IntPtr hwnd, IntPtr lParam);
private static bool EnumWindowsCallback(IntPtr hwnd, IntPtr lParam)
{
IntPtr pid = new IntPtr();
GetWindowThreadProcessId(hwnd, out pid);
var wndProcess = System.Diagnostics.Process.GetProcessById(pid.ToInt32());
var wndClass = new StringBuilder(255);
RealGetWindowClass(hwnd, wndClass, 255);
if (wndProcess.ProcessName == "explorer" && wndClass.ToString() == "CabinetWClass")
{
//hello file explorer window...
SendMessage(hwnd, WM_CLOSE, IntPtr.Zero, IntPtr.Zero); // ... bye file explorer window
}
return (true);
}
static void Main()
{
EnumWindowsDelegate childProc = new EnumWindowsDelegate(EnumWindowsCallback);
EnumWindows(childProc, IntPtr.Zero);
Console.ReadKey();
}
edit:
so i guess the only interesting thing is the callback which will be called by windows for each enumerated window (handle of said window in hwnd)
GetWindowThreadProcessId provides us with the processid for a given window handle
GetProcessById then provides us with a process object to read things like the process name from
RealGetWindowClass provides us with the registered class name for a given window handle
finally we can look to see if the process for the current window is the explorer and if the window class is "CabinetWClass", which is the window class for the normal file explorer window
last but not least, if our check is ok, send a WM_CLOSE message to kindly ask the window to close itself...
The following alternative uses the COM API of the Shell object to retrieve and identify File Explorer windows. It requires the addition of the COM references to:
Microsoft Shell Controls And Automation
Microsoft Internet Controls
The object returned by Shell.Windows method is an IEnumerable. Each object in the collection is a SHDocVw.InternetExplorer instance. If the Document object is a Shell32.ShellFolderView, then the explorer is a File Explorer.
private static void CloseExplorerWindows()
{
Shell32.Shell shell = new Shell32.Shell();
// ref: Shell.Windows method
// https://msdn.microsoft.com/en-us/library/windows/desktop/bb774107(v=vs.85).aspx
System.Collections.IEnumerable windows = shell.Windows() as System.Collections.IEnumerable;
if (windows != null)
{
// ref: ShellWindows object
// https://msdn.microsoft.com/en-us/library/windows/desktop/bb773974(v=vs.85).aspx
foreach (SHDocVw.InternetExplorer window in windows)
{
object doc = window.Document;
if (doc != null && doc is Shell32.ShellFolderView)
{
window.Quit(); // closes the window
}
}
}
}
public static void CloseExplorerWindows() => EnumWindows(new EnumWindowsProc(EnumTheWindows), IntPtr.Zero);
private delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Unicode)]
private static extern int GetWindowText(IntPtr hWnd, StringBuilder strText, int maxCount);
[DllImport("user32.dll", CharSet = CharSet.Unicode)]
private static extern int GetWindowTextLength(IntPtr hWnd);
[DllImport("user32.dll")]
private static extern bool EnumWindows(EnumWindowsProc enumProc, IntPtr lParam);
[DllImport("user32.dll")]
private static extern bool IsWindowVisible(IntPtr hWnd);
[DllImport("user32.dll", SetLastError = true)]
static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
static uint WM_CLOSE = 0x10;
private static bool EnumTheWindows(IntPtr hWnd, IntPtr lParam)
{
int size = GetWindowTextLength(hWnd);
if (size++ > 0 && IsWindowVisible(hWnd))
{
var sb = new StringBuilder(size);
GetWindowText(hWnd, sb, size);
var threadID = GetWindowThreadProcessId(hWnd, out var processID);
var s = System.Diagnostics.Process.GetProcessById((int)processID).ProcessName;
if (s == "explorer" && sb.ToString() != "Program Manager")
SendMessage(hWnd, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);
}
return true;
}
By default, explorer runs as single process, and any windows that open are just a thread of the process.
Normally, to close a program, you'd send a close message to the process. In this case, closing explorer.exe will close all explorer windows.
To close individual windows, you'd open each window via it's own process.
This can be done via registry setting or enabling under View->Options->View->Advanced Settings: "Launch ... separate process"
a) Find PID (process ID) of window you wanna close.
via taskmanager:
1. In list of processes, click the arrow to the left of "Windows Explorer"
2. Check the window name matches the window you wanna close
3. Right click on "Windows Explorer", click "Go to Details"
4. Record the pid
via CMD:
tasklist /V /FI "IMAGENAME eq explorer.exe"
If each explorer window is open in it's own process, the above command would display the window title in the last column.
Otherwise "N/A" would be displayed.
The pid of all explorer windows would be the same. Explorer.exe processes have their own pid, and title "N/A"
If 'separate process' has been enabled eg. via Folder View option, then each window can be closed via the process id & filter option of taskkill.
To close, the desired window has to be activated first, otherwise closing with pid will close the last active window, or closing with window title filter will give error:
INFO: No tasks running with the specified criteria.
b) taskkill /pid <pid>
will close the last active window.
Repeating this command will the next window.
or taskkill /im explorer.exe /fi "windowtitle eq <window name>"
or taskkill /fi "IMAGENAME eq explorer.exe" /fi "windowtitle eq <window name>"
< window name > is not case sensitive
If full path in title bar has been enabled in Folder view, then include full path or wildcards.
To close all explorer windows:
taskkill /im explorer.exe
Notes:
To activate explorer window, issue same command to open the window, if window reusing is enabled.
The pid of explorer window(ing) process is in the last row of the response table, in column "PID"; can be accessed via FOR loop.
A vbs workaround to close window from #HelpingHand: https://superuser.com/questions/1263315/how-to-close-a-particular-opened-folder-using-cmd-or-batch-file
A vbs workaround to activate window: http://superuser.com/questions/327676/application-to-automatically-switch-between-two-applications-in-windows
Tested on Win 10
I am new in C#, i've got some problem to capture any windows dialog show in my server. I need to know the message (caption and title) from windows dialog so i can write to my application log.
I know that i must find #32770 class windows, but i do not know how to enumwindows. In delphi 7, the code should use some functions like:
Enumwindows
EnumProcess
Enumchildwindows
Enumchildwindowsproc
Getwindowthreadprocessid
GetClassName
Getwindowtext
Is there any solution for this ?
You can use windows API in C# as well. You can find a lot information and examples of using here. And here is information about DllImport attribute.
You can try something like:
class Program
{
[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string className, string windowTitle);
static void Main(string[] args)
{
var handle = IntPtr.Zero;
do
{
handle = FindWindowEx(IntPtr.Zero, handle, "#32770", null);
if (handle != IntPtr.Zero )
Console.WriteLine("Found handle: {0:X}", handle.ToInt64());
} while (handle != IntPtr.Zero);
Console.ReadLine();
}
}
i've developed a simple application (.dll) in LABVIEW and i implorted that dll to a C# windows application(Winforms) . Like
[DllImport(#".\sample.dll")]
public static extern void MyFunc(char[] a, StringBuilder b ,Int32 c);
so when i call the function MyFunc a window will be popped up( the Lab View window( Front panel of my labview application
i need to get the window name (ExpectedFuncName) in my C# application. i.e i need to get the name of the external window which is opend by my C# application. Can we use FileVersionInfo or assembly loader to get the name?
Is there any idea to do this?
Thanks in advance.
If you have the window handle, this is relatively easy:
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);
[DllImport("user32.dll", SetLastError=true, CharSet=CharSet.Auto)]
static extern int GetWindowTextLength(IntPtr hWnd);
...
int len;
// Window caption
if ((len = GetWindowTextLength(WindowHandle)) > 0) {
sb = new StringBuilder(len + 1);
if (GetWindowText(WindowHandle, sb, sb.Capacity) == 0)
throw new Exception(String.Format("unable to obtain window caption, error code {0}", Marshal.GetLastWin32Error()));
Caption = sb.ToString();
}
Here, 'WindowHandle' is the handle of the created window.
In the case you do not have a window handle (I see you don't), you have to enumerate every desktop top-level window, filter them by the creating process (I see the window is created by you application by calling MyFunc, so you know the process ID [*]), and then use some heuristic to determine the required information.
Here is the C# import of the functions you shall use in the case you do not have the handle:
[DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
static extern int GetWindowThreadProcessId(IntPtr hWnd, out int lpdwProcessId);
[DllImport("user32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool EnumWindows(EnumWindowsProc lpEnumFunc, IntPtr lParam);
private delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);
Basically EnumWindows calls EnumWindowsProc for each window found in the current desktop. So you can get the window caption.
List<string> WindowLabels = new List<string>();
string GetWindowCaption(IntPtr hWnd) { ... }
bool MyEnumWindowsProc(IntPtr hWnd, IntPtr lParam) {
int pid;
GetWindowThreadProcessId(hWnd, out pid);
if (pid == Process.GetCurrentProcess().Id) {
// Window created by this process -- Starts heuristic
string caption = GetWindowCaption(hWnd);
if (caption != "MyKnownMainWindowCaption") {
WindowLabels.Add(caption);
}
}
return (true);
}
void DetectWindowCaptions() {
EnumWindows(MyEnumWindowsProc, IntPtr.Zero);
foreach (string s in WindowLabels) {
Console.WriteLine(s);
}
}
[*] In the case the window is not created by your application (i.e but from another background process), you shall filter the values returned by GetWindowThreadProcessId using another process ID, but this requires another question...
If you activate LabVIEW scripting (LabVIEW 2010), or install it (LV 8.6, 2009) there is a front-panel property called 'FP.nativewindow'. This returns a handle to the front panel window.
Use the following snippet to get the property:
I've been wondering how to do this for ages. I'm creating a little app, and I need to figure out how many apps or windows are displayed in the TaskBar.
I've yet to find any info on this at all, I'd appreciate any help at all.
Thank you :)
Here is an article that shows how to get the windows, that are shown when you are using the ALT+TAB key combination.
Basically, you will get the same windows that are shown in the taskbar (unless it is a tool window that is not displayed), but then again, you can always check against WS_EX_TOOLWINDOW (not shown) and WS_EX_APPWINDOW (shown).
You may have a look at my previous answer here; the main difference here is that you just have to count the windows that match the given requirements.
As other's have said you need to enumerate through the windows using the Win32 EnumWindows function, and get your count that way.
You can also enumerate through processes using Process.GetProcesses(); However windows like explorer windows which are not a separate process will not show up in that list.
int appCount = 0;
public bool EnumerateWindows(IntPtr hwnd, IntPtr lParam)
{
if (IsWindowVisible(hwnd))
{
StringBuilder sb = new StringBuilder();
string text = "";
GetWindowText(hwnd, sb, 1024);
text = sb.ToString();
if (text != string.Empty && text != "Program Manager")
{
appCount++;
}
}
return true;
}
private int GetAppCount()
{
appCount = 0;
EnumWindows(EnumerateWindows, new IntPtr(0));
return appCount;
}
internal delegate bool EnumThreadWindowsCallback(IntPtr hwnd, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
internal static extern bool EnumWindows(EnumThreadWindowsCallback callback, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
internal static extern bool IsWindowVisible(IntPtr hwnd);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
internal static extern int GetWindowText(IntPtr hWnd, [Out, MarshalAs(UnmanagedType.LPTStr)] StringBuilder lpString, int nMaxCount);
As far as I know there is no managed way of accessing the taskbar. Here is a link that describes how to access the taskbar by the Windows API. However, I a quick scan did not show any "number of items" or something similar. Still it might point you in the right direction.