iOS 中 GIF 图片的显示方法

iPhone SDK提供了多种动画手段，UIView、UIImageView和CALayer都支持动画。但如何处理常见的gif动画呢？UIWebView提供了答案，代码如下：

1. 使用UIWebView播放
    // 设定位置和大小
    CGRect frame = CGRectMake(50,50,0,0);
    frame.size = [UIImage imageNamed:@"guzhang.gif"].size;
    // 读取gif图片数据
    NSData *gif = [NSData dataWithContentsOfFile: [[NSBundle mainBundle] pathForResource:@"guzhang" ofType:@"gif"]];
    // view生成
    UIWebView *webView = [[UIWebView alloc] initWithFrame:frame];
    webView.userInteractionEnabled = NO;//用户不可交互
    [webView loadData:gif MIMEType:@"image/gif" textEncodingName:nil baseURL:nil];
    [self.view addSubview:webView];
    [webView release];


2.将gif图片分解成多张png图片，使用UIImageView播放。
代码如下：
 UIImageView *gifImageView = [[UIImageView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    NSArray *gifArray = [NSArray arrayWithObjects:[UIImage imageNamed:@"1"],
                                                  [UIImage imageNamed:@"2"],
                                                  [UIImage imageNamed:@"3"],
                                                  [UIImage imageNamed:@"4"],
                                                  [UIImage imageNamed:@"5"],
                                                  [UIImage imageNamed:@"6"],
                                                  [UIImage imageNamed:@"7"],
                                                  [UIImage imageNamed:@"8"],
                                                  [UIImage imageNamed:@"9"],
                                                  [UIImage imageNamed:@"10"],
                                                  [UIImage imageNamed:@"11"],
                                                  [UIImage imageNamed:@"12"],
                                                  [UIImage imageNamed:@"13"],
                                                  [UIImage imageNamed:@"14"],
                                                  [UIImage imageNamed:@"15"],
                                                  [UIImage imageNamed:@"16"],
                                                  [UIImage imageNamed:@"17"],
                                                  [UIImage imageNamed:@"18"],
                                                  [UIImage imageNamed:@"19"],
                                                  [UIImage imageNamed:@"20"],
                                                  [UIImage imageNamed:@"21"],
                                                  [UIImage imageNamed:@"22"],nil];
    gifImageView.animationImages = gifArray; //动画图片数组
    gifImageView.animationDuration = 5; //执行一次完整动画所需的时长
    gifImageView.animationRepeatCount = 1;  //动画重复次数
    [gifImageView startAnimating];
    [self.view addSubview:gifImageView];
    [gifImageView release];

注意：这个方法，如果gif动画每桢间的时间间隔不同，不能达到此效果。