Use IAccPropServices on slider controls in Classic client

[bear101]

For me, the labeling doesn't work with either NVDA or Narrator.

It seems you're using SetWindowText to set the labels:
m_wndVolSlider.SetWindowText(szCtrlName);
Accessibility doesn't look at window text for sliders. Instead, you should use MSAA direct dynamic annotation:
https://msdn.microsoft.com/en-us/library/windows/desktop/dd318057(v=vs.85).aspx
Something like the following should do the trick:
IAccPropServices* accPropServices = NULL;
CoCreateInstance(CLSID_AccPropServices, NULL, CLSCTX_SERVER, IID_IAccPropServices, (void**)&accPropServices);
...
accPropServices->SetHwndPropStr(sliderHwnd, OBJID_CLIENT, CHILDID_SELF, PROPID_ACC_NAME, szCtrlName);

[jcsteh]

(Posting here rather than the blog to make tracking easier.)

Bjoern wrote:

Hi James, I get the following error when I try to build:
error LNK2001: unresolved external symbol CLSID_AccPropServices
What library do I need to link?

It's not a library you need to link. Rather, you need to #include <initguid.h> and #include <oleacc.h> (in that order).