GetWindowText

GetWindowText is a Windows API function used to retrieve the text content of a specified window or control within a graphical user interface. It is commonly employed in Windows programming and automation tasks to obtain the current caption, label, or text displayed in a window, dialog box, or control element such as a textbox, button, or label.

The function prototype is typically declared as:

int GetWindowTextA(HWND hWnd, LPSTR lpString, int nMaxCount);

or its Unicode equivalent:

int GetWindowTextW(HWND hWnd, LPWSTR lpString, int nMaxCount);

where hWnd is a handle to the target window or control, lpString is a buffer that receives the window’s text, and nMaxCount specifies the maximum number of characters to copy, including the null-terminator. The function returns the number of characters copied, not including the null-terminator.

GetWindowText is useful in scenarios such as UI automation, testing, and accessibility, allowing programs to read and verify displayed text. It is important to allocate sufficient buffer size to avoid truncation of the retrieved text.

Limitations include its inability to retrieve text from certain window classes that do not store text in the standard manner or from owner-drawn controls, which may require alternative methods such as sending specific messages or using other APIs.

The function is part of the Windows User32 library and is documented extensively in Microsoft's developer resources, making it a fundamental tool for Windows-based application development and interface automation.