Getting the window title from a process name

I am trying to write a program that can get the window title of a process. Before I describe the problem, here is the code:

The program works so far, until I want to get the actual title of the window. I tried GetWindowText and SendMessage, as shown here. Both methods return empty strings.

How can I get the window title?

2 Answers 2

The following code works for a similar problem. In my case I am looking for the windows handle of an application so that I can parent a dll. I identify the app by its caption. Its C++Builder code so some parts may be unfamiliar. I’ll comment the differences I spot. The main one is the use of Application, I’m not sure what the non-Embarcadero equivalent is, but each running instance of code has an Application instance that manages the message loop and so on. I set my dll’s Application->Handle to the calling apps hWnd to keep it off the taskbar, among other things. This code works on xp, vista 32 and win7 64.

Hope this helps.

It seems that (WPARAM)sizeof(CHAR)/sizeof(MAX_PATH) would return you zero, because sizeof(char) will be defenetly smaller then the max path, so you say to WinAPI that your variable has zero length, that’s why it returns empty string to you. Specify there MAX_PATH value instead.

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Windows c get window title

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Question

I have problem in getting the window caption for C# application, tried using FindWindow api, but not able to solve the problem. Is it possible retriving the Caption of a window using form name.

Answers

public class Program

public static void Main ( )

IntPtr hwnd = UnsafeNativeMethods .FindWindow( «Notepad» , null );

StringBuilder stringBuilder = new StringBuilder (256);

UnsafeNativeMethods .GetWindowText(hwnd, stringBuilder, stringBuilder.Capacity);

internal static class UnsafeNativeMethods

[ DllImport ( «user32.dll» , SetLastError = true , CharSet = CharSet .Auto)]

internal static extern int GetWindowText ( IntPtr hWnd, [ Out ] StringBuilder lpString, int nMaxCount );

[ DllImport ( «user32.dll» , SetLastError = true )]

internal static extern IntPtr FindWindow ( string lpClassName, string lpWindowName );

All replies

That’s going to be very hard. A form has a dynamically generated class name that looks like this: «WindowsForms.10.Window.8.app.0.14fd2b5». «10» is the Windows Forms version number, «8» is the window style, «0» is the number of window classes generated in the AppDomain minus one, «14fd2b5» is the hash code for AppDomain. There’s just no way you could guess the class name, FindWindow(Ex) is out. EnumWindows() is possible but you’ll need something to uniquely identify the window you’re interested in (such as the client controls, find them with EnumChildWindows).

In addition, GetWindowText() cannot directly retrieve the window title for a window that belongs to another application. You would have to allocate memory for the text buffer in the process space of the application (VirtualAllocEx() and ReadProcessMemory()).

You’ve got some Google search keywords here, good luck!

public class Program

public static void Main ( )

IntPtr hwnd = UnsafeNativeMethods .FindWindow( «Notepad» , null );

StringBuilder stringBuilder = new StringBuilder (256);

UnsafeNativeMethods .GetWindowText(hwnd, stringBuilder, stringBuilder.Capacity);

internal static class UnsafeNativeMethods

[ DllImport ( «user32.dll» , SetLastError = true , CharSet = CharSet .Auto)]

internal static extern int GetWindowText ( IntPtr hWnd, [ Out ] StringBuilder lpString, int nMaxCount );

[ DllImport ( «user32.dll» , SetLastError = true )]

internal static extern IntPtr FindWindow ( string lpClassName, string lpWindowName );

How do I get the title of the current active window using c#?

I’d like to know how to grab the Window title of the current active window (i.e. the one that has focus) using C#.

7 Answers 7

See example on how you can do this with full source code here:

Edited with @Doug McClean comments for better correctness.

If you were talking about WPF then use:

It supports UTF8 characters.

Loop over Application.Current.Windows[] and find the one with IsActive == true .

Use the Windows API. Call GetForegroundWindow() .

GetForegroundWindow() will give you a handle (named hWnd ) to the active window.

If it happens that you need the Current Active Form from your MDI application: (MDI- Multi Document Interface).

you can use process class it’s very easy. use this namespace

if you want to make a button to get active window.

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Windows: Getting a window title bar’s height

I was trying to get the height of the title bar of a specific window on Windows. You can replicate it with Notepad. I’m using C++ and none of the codes I found online yielded the correct result. Using e.g. Screenpresso I measured 31 pixels for my window bar height.

The functions I tried are the following:

Getting the system metrics with GetSystemMetrics() does not work because windows can have different title bar heights obviously and there is no argument for the window handle.

How can I really get the result of 31 ?

4 Answers 4

Assuming that you don’t have menu bar, you can map points from client coordinate system to screen one

Got 8, 8, 8 and 31 pixels (96DPI aka 100% scaling setting)

You should also take into account DPI awareness mode. Especially GetSystemMetrics is tricky because it remembers state for System DPI when your application was launched.

Send a message WM_GETTITLEBARINFOEX to the window, and you will get the bounding rectangle of the title bar.

If I’ve understood correctly, it looks like you want to take the border size of the window (which we should be able to gather from the width as there is no title bar) and subtract it from the the verticle size minus the client window.

First, make sure your application is high DPI aware so that the system doesn’t lie to you.

Trust GetSystemMetrics. Nearly any top-level window that actually has a different caption size is doing custom non-client area management which is going to make it (nearly) impossible. The obvious exception is a tool window (WS_EX_TOOLWINDOW) which probably has a SM_CYSMCAPTION height if the WS_CAPTION style is also set.

Get the target window rect and the target window’s style. Use AdjustWindowRectEx to determine the size differences with the WS_CAPTION style toggled. I’m not sure if this will work because there may be some interaction between on whether you can have a caption without some kind of border.

Get the target window rect and send WM_HITTEST messages for coordinates that move down the window. Count how many of those get HT_CAPTION in return. Bonus points if you do this with a binary search rather than a linear search. This is probably the hardest and the most reliable way to do it, assuming the window has a rectangular caption area.

Return Window handle by it’s name / title

I can’t solve this problem. I get an error:

It sounds very easy and probably is. sorry for asking so obvious questions.

I tried with many different ways and each fails. Thanks in advance.

6 Answers 6

Update: See Richard’s Answer for a more elegant approach.

Don’t forget you’re declaring you hWnd inside the loop — which means it’s only visible inside the loop. What happens if the window title doesn’t exist? If you want to do it with a for you should declare it outside your loop, set it inside the loop then return it.

Or in a more LINQ-y way.

Because you are declaring hWnd inside the if block, it is inaccessible to the return statement which is outside it. See http://www.blackwasp.co.uk/CSharpVariableScopes.aspx for clarification.

The code you’ve provided can be fixed by moving the declaration of the hWnd variable:

Coming several years late to this but, as others have mentioned, the scope of hWnd is only in the foreach loop.

However it’s worth noting that, assuming you’re doing nothing else with the function, then there are two issues with the answers others have provided:

1. The variable hWnd is actually unnecessary since it’s only being for one thing (as the variable for the return )
2. The foreach loop is inefficient as, even after you’ve found a match, you continue to search the rest of the processes. In actual fact, it’ll return the last process it finds that matches.

Assuming that you don’t want to match the last process (point #2), then this is a cleaner and more efficient function: