NSTimer移动图像

Question

I have an large image I have put in an image view. the image view is larger than the screen, and i set it up to move in diagonal downwards at a certain speed.

the image does move, but at a certain point we see the white because the image has slider away. I would like to continue sliding the image like if it was a globe. or at least change the direction to opposite. I tried this:

- (void) onTimer {
palla.center = CGPointMake(palla.center.x+1, palla.center.y+1);
    if (palla.center.x > -20000||palla.center.x < 20000){
    CGPointMake(palla.center.x-1, palla.center.y+-1);    
}

unfortunately it does not work. I even tried pos, but still does not work. how can I fizx this????? please help, I can't find any tutorials online

Answer 1

You can try this. I have written with iphone in mind. "image" is the image view.

-(void)onTimer
{
    CGRect imageRect = image.frame;

    if (CGRectContainsPoint(CGRectMake(0, 0, 320, 460), image.center))
    {
        image.center = CGPointMake(image.center.x + 50, image.center.y + 50);
    }
    else
    {
        image.frame = CGRectMake(0, 0, imageRect.size.width, imageRect.size.height);
    }

Answer 2

1. easy way..make a new image view..
2. set it to a image that is in opposite direction ..to the first one..

3. now animate both the way you are doing..keeping the

   second origin = first image view.origin - image view.frame.width.

4. When a view goes out of the screen..place it behind of other.