You can disable your app window and/or show a modal dialog while the worker thread is active and re-enable when it finishes. So the message loop is not blocked and repainting is ensured while the app itself is blocked.
What do you mean by floating windows? There is no additional window.
I have created a sample console app (windows universal) using VS2015. If I call the method QueryDosDevice(), it results into ERROR_ACCESS_DENIED error. I am deploying this app on Windows 10. Interestingly I can call APIs from ntdll. But seems like it gives access denied error if I try to call APIs from kernel32.
Are there are access (perhaps for volume management APIs) restrictions introduced for universal apps? If yes, Is there any way around it?
Assigning administrator rights to an application requires administrative privileges. So while it does not have these, you can't change it. And you can not elevate the privileges of a running process.
You can use a manifest to specify that your application should run elevated, use the "runas" command or start other applications elevated from within your program. But in all these cases there will be a UAC prompt.
UAC is there for a reason. It is a security feature. The user decides which level of security should be used. An application can not bypass these settings.
l want to ask how l can do the following things in a tab control.
1)That is, for instance: In tab1, when a button is clicked, previous text is wiped and another is written. l had tried but all the texts overlaps and none cleanses off fornew texts.
2)How can l erase the content of a tab control when l switch tabs. As in, when tab2 is clicked, contents in tab1 clears off and the things in tab2 only shows.
When you get the TCN_SELCHANGE notification (in a WM_NOTIFY message) you have to clear or hide the contents of the old tab and show the contents of the new tab yourself - the API doesn't help you with it.