How to pass multiple bits of information via NSTimer

[iamstuck]

Hi there,

Thanks in advance for any help anyone can offer. I'm pretty new to all this.

I come from a background of coding in Actionscript, so maybe I'm approaching this in the wrong way...

Basically, I'm moving a series of balls on the iphone screen. Every time the user taps the screen a new ball is created.

I want to pass each ball an X and Y velocity (let's call them vx and vy) and then move the ball based on these vx and vy values, using a timer.

I can get all of it working fine, except...

How do I pass a newly created ball it's X and Y velocity (vx and vy values).

Like I say, I'm used to Actionscript where I could give an object properties like ball.vx = 10 and ball.vy = 20 and then access those.

I want to be able to do the same thing here but I can't figure it out at all.

I'm passing the ball itself to the function called by the timer using "userInfo" as follows:

[NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(moveBall:) userInfo:ballImageView repeats:YES];

But how do I get the initial vx and vy values into each newly created ball? They'll be different each time so I can't use a global variable to store these, and as soon as each ball starts moving I apply gravity to the vy, thereby changing it.

I tried ballImageView.vx = 10 etc. but that didn't work.

Any help would be much appreciated. I know it will be a very simple answer as this is very basic in other programming languages but I've searched everywhere and can't find what I need.

Many thanks.

Ian

[iamstuck]

Hi there,

Sorry to send this back to the top. I know it's not good form, and I appreciate if anyone had an answer by now they would have posted it, but I'm really struggling still and the post has slipped off the first page so quickly I was hoping someone who hasn't seen it yet may have an answer. I really have looked everywhere and can't figure this out. Any help would be really appreciated.

It must be a simple thing to do because it's so easy in other languages (ie: Actionscript).

I essentially want to end up with each ball having a series of properties as in:

ball.vx = 10;
ball.vy = 10;
ball.ballAngle = 72;

which I can then access, change etc. and only have them apply to their individual ball.

Am I right in thinking there's a way to achieve this? In AS it's so simple, but whatever I try here just kicks back errors or crashes my app.

Thanks.

Ian

[smithdale87]

what is "ball"? A UIImageView?

[iamstuck]

Originally Posted by smithdale87

what is "ball"? A UIImageView?

Yes - it is a UIImageView.

Thanks.

Ian

[smithdale87]

So a UIImageView doesnt' know what vx, vy are. You have to tell it first ( unlike in ActionScript I'm assuming ).

One solution would be to subclass UIImageView and give it the properties you want. You can call this new class BallImageView or something. If you don't know what I mean by subclass, i recommend you look for some tutorials.