WinApi, getting text from a control, invisible text and visible text show nothing

So since i can't make a peace with myself as i really want to dig deep here and understand how this works i am in the middle of trouble. Why is this control not showing any text in visible text or visible text area.

It 开发者_StackOverflowconstantly streams text but its never available to a tool like spy++.

so i figure using some commands like sending a message wm_gettext wouldnt do much here? What are your suggestions, thanks

The Windows Controls (in User32.dll and Comctl32.dll) are just one possible way of building the user interface of an application. When using those controls (or a UI library, such as MFC, which makes use of them), the application communicates with the control elements through window messages, such as the WM_GETTEXT you are trying to intercept.

But there are other GUI libraries (WPF, FOX Toolkit just to name a few), which paint their own controls, and use other mechanisms than window messages to exchange information with them (eg. function calls).

Spy++ won't help you there. You'd need to attach a debugger and monitor calls to the relevant API functions.