当iphone在loading比较多数据时，怎么样让窗口显示等待图标

[[CCDirector sharedDirector]UIActivityIndicatorView *activityIndicator= [[UIActivityIndicatorView alloc]                             initWithFrame:CGRectMake(0.0f, 0.0f, 32.0f,32.0f)]; [activityIndicator setActivityIndicatorViewStyle:UIActivityIndicatorViewStyleGray]; [contentView addSubview:activityIndicator]; [activityIndicator startAnimating];        //loading data.....[activityIndicator stopAnimating];[activityIndicator release];

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