走马灯（四个方格循环移动）

#import "ViewController.h"@interface ViewController ()@endstatic BOOL bool1 = YES;@implementation ViewController- (void)viewDidLoad{    [super viewDidLoad];        view1 = [[UIView alloc]init];    view1.frame = CGRectMake(0, 0, 320, 480);    view1.backgroundColor =[UIColor greenColor];    [self.view addSubview:view1];        label1 = [[UILabel alloc]initWithFrame:CGRectMake(10, 100, 100, 100)];//    label1.text = @"a";    label1.backgroundColor = [UIColor redColor];    [view1 addSubview:label1];        label2 = [[UILabel alloc]initWithFrame:CGRectMake(110, 100, 100, 100)];//    label2.text = @"b";    label2.backgroundColor = [UIColor blueColor];    [view1 addSubview:label2];        label3 = [[UILabel alloc]initWithFrame:CGRectMake(10, 200, 100, 100)];//    label3.text = @"c";    label3.backgroundColor = [UIColor purpleColor];    [view1 addSubview:label3];    label4 = [[UILabel alloc]initWithFrame:CGRectMake(110, 200, 100, 100)];//    label4.text = @"d";    label4.backgroundColor = [UIColor yellowColor];    [view1 addSubview:label4];        button1 = [UIButton buttonWithType:UIButtonTypeRoundedRect];    button1.frame = CGRectMake(10, 320, 80, 30);    [button1 setTitle:@"顺时针" forState:UIControlStateNormal];    [button1 addTarget:self action:@selector(change) forControlEvents:UIControlEventTouchUpInside];    [view1 addSubview:button1];        button2 = [UIButton buttonWithType:UIButtonTypeRoundedRect];    button2.frame = CGRectMake(130, 320, 80, 30);    [button2 setTitle:@"逆时针" forState:UIControlStateNormal];    [button2 addTarget:self action:@selector(changele) forControlEvents:UIControlEventTouchUpInside];    [view1 addSubview:button2];    // Do any additional setup after loading the view, typically from a nib.}//顺时针-(void)change{    if (bool1 == YES) {        [UIView beginAnimations:@"testA" context:NULL];//开始动画        [UIView setAnimationDuration:1];//动画持续时间        [UIView setAnimationCurve:UIViewAnimationCurveLinear];        [UIView setAnimationDelegate:self];//动画代表//        [UIView setAnimationRepeatAutoreverses:YES];//设置动画重复自动反转        [UIView setAnimationRepeatCount:99];//循环次数        a = [[UIView alloc]init];        a.center = label1.center;        label1.center = label2.center;        label2.center = label4.center;        label4.center = label3.center;        label3.center = a.center;        [UIView commitAnimations];        [button1 setTitle:@"返回" forState:UIControlStateNormal];        [a release];        bool1 = NO;    }    else {        [UIView beginAnimations:@"testA" context:NULL];        [UIView setAnimationDuration:1];        [UIView setAnimationCurve:UIViewAnimationCurveLinear];        [UIView setAnimationDelegate:self];        [UIView setAnimationRepeatAutoreverses:NO];        [UIView setAnimationRepeatCount:0];        a = [[UIView alloc]init];        a.center = label1.center;        label1.center = label2.center;        label2.center = label4.center;        label4.center = label3.center;        label3.center = a.center;        [UIView commitAnimations];        [button1 setTitle:@"顺时针" forState:UIControlStateNormal];        [a release];        bool1 = YES;    }}//逆时针-(void)changele{    if (bool1 == YES) {        [UIView beginAnimations:@"testA" context:NULL];        [UIView setAnimationDuration:1];        [UIView setAnimationCurve:UIViewAnimationCurveLinear];        [UIView setAnimationDelegate:self];        [UIView setAnimationRepeatAutoreverses:NO];        [UIView setAnimationRepeatCount:99];        a = [[UIView alloc]init];        a.center = label3.center;        label3.center = label4.center;        label4.center = label2.center;        label2.center = label1.center;        label1.center = a.center;        [UIView commitAnimations];        [button2 setTitle:@"返回" forState:UIControlStateNormal];        [a release];        bool1 = NO;    }    else {        [UIView beginAnimations:@"testA" context:NULL];        [UIView setAnimationDuration:1];        [UIView setAnimationCurve:UIViewAnimationCurveLinear];        [UIView setAnimationDelegate:self];        [UIView setAnimationRepeatAutoreverses:NO];        [UIView setAnimationRepeatCount:0];        a = [[UIView alloc]init];        a.center = label3.center;        label3.center = label4.center;        label4.center = label2.center;        label2.center = label1.center;        label1.center = a.center;        [UIView commitAnimations];        [button2 setTitle:@"逆时针" forState:UIControlStateNormal];        [a release];        bool1 = YES;    }}-(void)dealloc{    [view1 release];    [label1 release];    [label2 release];    [label3 release];    [label4 release];    [super dealloc];}- (void)viewDidUnload{    [super viewDidUnload];    // Release any retained subviews of the main view.}- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{    return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);}@end