macoscocoakeyboardnsevent

How press "shift" + "command" + "3" simultaneously programmatically

I am trying to capture a screenshot by posting this Keyboard event. I tried below way which doesn't work:

1]

CGEventRef event1, event2, event3, event4, event5, event6;
event1 = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)56, true);
event2 = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)55, true);
event3 = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)85, true);//or 20
event4 = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)85, false);// or 20
event5 = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)55, false);
event6 = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)56, false);

CGEventPost(kCGSessionEventTap, event1);
CGEventPost(kCGSessionEventTap, event2);
CGEventPost(kCGSessionEventTap, event3);

CGEventPost(kCGSessionEventTap, event4);
CGEventPost(kCGSessionEventTap, event5);
CGEventPost(kCGSessionEventTap, event6);

CFRelease(event1);
CFRelease(event2);
CFRelease(event3);
CFRelease(event4);
CFRelease(event5);
CFRelease(event6);

2] 

CGEventRef event7;
event7 = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)85, true);//or 20
CGEventSetFlags(event7, kCGEventFlagMaskShift);
CGEventSetFlags(event7, kCGEventFlagMaskCommand);
CGEventPost(kCGSessionEventTap, event7);
CFRelease(event7);

Both are not working. Suggest me any good option.

Solution

  • 1] doesn't work because you don't set the event flags. 2] doesn't work because you don't post the key-up event and CGEventSetFlags(event7, kCGEventFlagMaskCommand); replaces the kCGEventFlagMaskShift flag. Set both flags:

    CGEventRef event7;
event7 = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)85, true);//or 20
CGEventSetFlags(event7, kCGEventFlagMaskShift | kCGEventFlagMaskCommand);
CGEventPost(kCGSessionEventTap, event7);
CFRelease(event7);

event7 = CGEventCreateKeyboardEvent (NULL, (CGKeyCode)85, false);//or 20
CGEventSetFlags(event7, kCGEventFlagMaskShift | kCGEventFlagMaskCommand);
CGEventPost(kCGSessionEventTap, event7);
CFRelease(event7);