Author: h.mohri

C++Builder 10.2 BCC32 can not write lambda. 
So write an implementation in Invoke() with TCppInterfacedObject<>.

Event prepared for calling with TThread::Synchronize().

Call TThread::CreateAnonymousThread() with a TButton event.

Place the TButton and TActivityIndicator

Build execution.

When you click the Button1, until the thread is finished "ActivityIndicator1->Animate = true";