Flash动作脚本3，按键碰撞检测

Question

I am trying to get my character to collide with the walls I have created but I am having difficulties doing so, I have tried using solutions in other threads but none have worked. help please. Essentially I got collision detection working, however it only activates upon clicking, with a mouse event.

square1_mc.addEventListener(MouseEvent.MOUSE_DOWN, drag);
stage.addEventListener(MouseEvent.MOUSE_UP, drop);

function drag(e: MouseEvent): void {    
    e.target.startDrag();
}

function drop(): void {
    head_mc.x -= velocity;
    stopDrag();

    if (head_mc.hitTestObject(square2_mc)) {
        velocity = 0;    
        trace("Collision detected!");
    } else {
        trace("No collision.");
        velocity = 5;
    }
}

What I am trying to do is, make head_mc , my player model, stop moving to the right upon colliding with square_mc , my wall. It only works when I click on the object, I need it to work by only moving the head_mc to the block my using my arrow keys.

Answer 1

You can only detect collision upon clicking because you have put your hitTestObject inside a function that is a MouseEvent function. What you could do is that instead of testing collision on MOUSE_UP and MOUSE_DOWN , test the collision with a frequent interval of time by either using TimerEvent or directly calling the function through Event.ENTER_FRAME . That way, the program will keep checking for collision after a very short interval of time and hence, when collision is detected, the function could trace out trace("Collision detected!"); and every second it is not colliding, it will keep tracing trace("No collision."); and your velocity will be set to 5.

you could add a function this way:

function checkCollision(e: Event): void {
  if (head_mc.hitTestObject(square2_mc)) {
    velocity = 0;
    trace("Collision detected!");
  } else {
    trace("No collision.");
    velocity = 5;
  }
}

stage.addEventListener(Event.ENTER_FRAME, checkCollision);