iOS启动图加载动态Gif

// 设定位置和大小  
    CGRect frame = CGRectMake(50,340,[UIScreen mainScreen].bounds.size.width / 2,[UIScreen mainScreen].bounds.size.height / 2);  
    frame.size = [UIImage imageNamed:@"640gif.gif"].size;    
    // 读取gif图片数据  
    NSData *gif = [NSData dataWithContentsOfFile: [[NSBundle mainBundle] pathForResource:@"640gif" 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];