UIActivityIndicatorView

#define SCREEN_WIDHT [[UIScreen mainScreen] bounds].size.width

#define SCREEN_HEIGHT [[UIScreen mainScreen] bounds].size.height

UIActivityIndicatorView這樣用滴：

UIActivityIndicatorView *ViewActivityIndicator = [[UIActivityIndicatorViewalloc]initWithActivityIndicatorStyle:

UIActivityIndicatorViewStyleWhiteLarge];

    //設置在屏幕中心

    ViewActivityIndicator.center =CGPointMake(SCREEN_WIDHT/2,SCREEN_HEIGHT/2);

    [self.viewaddSubview:ViewActivityIndicator];

    // 改變圈圈的顏色

    ViewActivityIndicator.color = [UIColorgreenColor];

    // 開始旋轉

    [ViewActivityIndicator startAnimating];

    // 結束旋轉

    [ViewActivityIndicator stopAnimating];

    //當旋轉結束時隱藏

    [ViewActivityIndicator setHidesWhenStopped:YES];

    //判斷當前是否在旋轉

    if([ViewActivityIndicatorisAnimating]){

        NSLog(@"在轉");

    }else{

        NSLog(@"不在轉");

    }