ReplaceTextA function (commdlg.h)

Creates a system-defined modeless dialog box that lets the user specify a string to search for and a replacement string, as well as options to control the find and replace operations.


HWND ReplaceTextA(
  LPFINDREPLACEA unnamedParam1




A pointer to a FINDREPLACE structure that contains information used to initialize the dialog box. The dialog box uses this structure to send information about the user's input to your application. For more information, see the following Remarks section.

Return value

Type: HWND

If the function succeeds, the return value is the window handle to the dialog box. You can use the window handle to communicate with the dialog box or close it.

If the function fails, the return value is NULL. To get extended error information, call the CommDlgExtendedError function, which can return one of the following error codes:


The ReplaceText function does not perform a text replacement operation. Instead, the dialog box sends FINDMSGSTRING registered messages to the window procedure of the owner window of the dialog box. When you create the dialog box, the hwndOwner member of the FINDREPLACE structure is a handle to the owner window.

Before calling ReplaceText, you must call the RegisterWindowMessage function to get the identifier for the FINDMSGSTRING message. The dialog box procedure uses this identifier to send messages when the user clicks the Find Next, Replace, or Replace All buttons, or when the dialog box is closing. The lParam parameter of a FINDMSGSTRING message contains a pointer to the FINDREPLACE structure. The Flags member of this structure indicates the event that caused the message. Other members of the structure indicate the user's input.

If you create a Replace dialog box, you must also use the IsDialogMessage function in the main message loop of your application to ensure that the dialog box correctly processes keyboard input, such as the TAB and ESC keys. The IsDialogMessage function returns a value that indicates whether the Replace dialog box processed the message.

You can provide an FRHookProc hook procedure for a Replace dialog box. The hook procedure can process messages sent to the dialog box. To enable a hook procedure, set the FR_ENABLEHOOK flag in the Flags member of the FINDREPLACE structure and specify the address of the hook procedure in the lpfnHook member.


The commdlg.h header defines ReplaceText as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.


Minimum supported client Windows 2000 Professional [desktop apps only]
Minimum supported server Windows 2000 Server [desktop apps only]
Target Platform Windows
Header commdlg.h (include Windows.h)
Library Comdlg32.lib
DLL Comdlg32.dll
API set ext-ms-win-shell-comdlg32-l1-1-1 (introduced in Windows 10, version 10.0.14393)

See also


Common Dialog Box Library