newbie question on updating color on UIView

I am using a UIView object that simply sets the background color to blue. This works fine the first time the code runs, but running the changeBackgroundColor mehod 开发者_JAVA技巧again (from a button action) doesnt change the color to red, even though debugging the code clearly shows the method runs as expected.

Please could someone explain why the view color doesnt update?

Header:

@interface colorClass : NSObject {  
    UIView *myView; 
}

@implementation
...
-(UIView *)changeBackgroundColor {

    myView  = [[UIView alloc] initWithFrame:CGRectMake(100, 0, 500, 245)];

    static int counter = 1;
    if (counter++ %2){
        [mediaView setBackgroundColor:[UIColor blueColor]];
    }else {
        [mediaView setBackgroundColor:[UIColor redColor]];

    }
    return myView;
}

---

Have yout tried [yourView setNeedsDisplay] after changing colors ?

Edit:

-(UIView *)changeBackgroundColorof:(UIView *)view {

static int counter = 1;
if (counter++ %2){
    [view setBackgroundColor:[UIColor blueColor]];
}else {
    [view setBackgroundColor:[UIColor redColor]];

}
    return view;
}

you'd have to initialize your view elswhere then with

yourView  = [[UIView alloc] initWithFrame:CGRectMake(100, 0, 500, 245)];

and call

yourview = [self changeBackgroundColorof:yourview];

---

Thanks to both for pointing me in the right direction. In the end, I needed to create a new init method, and now the code works exactly as I hoped.

-(id)init {

myView      = [[UIView alloc] initWithFrame:CGRectMake(100, 0, 500, 245)];  
return self;

}