How to simulate a continuous key press

I need to simulate a continuous key press. For example hold down the ‘c’ key for 5 seconds. To simulate a key press event I tried to use CGEventCreateKeyboardEvent:

let event:CGEventRef! = CGEventCreateKeyboardEvent(nil, 8, true)
CGEventPost(CGEventTapLocation.CGSessionEventTap, event)

But it acts like if the button is tapped and then released immediately. I need to create an event that keeps holding the button (key down) and then release it (key up).

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  • Solutions Collect From Internet About “How to simulate a continuous key press”

    I’m not sure what you are trying to achieve, but it appears that the system will continue to hold the button down. This simple experiment shows it.

    func applicationDidFinishLaunching(aNotification: NSNotification) {
        print("waiting 4 seconds, use this time to position your cursor in a text field")
        let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(4 * Double(NSEC_PER_SEC)))
        dispatch_after(delayTime, dispatch_get_main_queue(), {
    func insertLetterZ() {
        print("pressing shift")
        print("holding button for 2 seconds")
        let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(2 * Double(NSEC_PER_SEC)))
        dispatch_after(delayTime, dispatch_get_main_queue(), {
            print("tapping z, but Z will be selected (since shift is still being pressed)")
            print("untapping z and shift")
    func tapButton(button: CGKeyCode) {
        let event = CGEventCreateKeyboardEvent(nil, button, true)
        CGEventPost(CGEventTapLocation.CGSessionEventTap, event)
    func untapButton(button: CGKeyCode) {
        let event = CGEventCreateKeyboardEvent(nil, button, false)
        CGEventPost(CGEventTapLocation.CGSessionEventTap, event)

    This code however does not capitalize a letter if a user taps the keyboard when shift is programmatically pressed. I have also noticed that if the cursor location is changed between shift and z being tapped “z” will be inserted instead of “Z”