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

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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.