iOS 实现简单的加载等待动画示例（思路与实现）

让圈圈转起来添加动画

    CABasicAnimation *animation=[CABasicAnimation     animationWithKeyPath:@"transform.rotation.z"]; ;
    // 设定动画选项
    animation.duration = 1;
    animation.removedOnCompletion = NO;
    animation.fillMode = kCAFillModeForwards;
    animation.repeatCount =HUGE_VALF;
    // 设定旋转角度
    animation.fromValue = [NSNumber numberWithFloat:0.0]; // 起始角度
    animation.toValue = [NSNumber numberWithFloat:2 * M_PI]; // 终止角度
    [circleView.layer addAnimation:animation forKey:@"rotate-layer"];

    UILabel *label=[[UILabel alloc]init];
    label.text=@"测试中";
    label.font=[UIFont systemFontOfSize:32];
    label.textAlignment=NSTextAlignmentCenter;
    label.frame=CGRectMake(0, 0,frame.size.width,frame.size.height);
    label.backgroundColor=[UIColor clearColor];
    [self addSubview:label];

//创建XDColorCircle的实例化对象
 XDColorCircle *circle=[[XDColorCircle alloc]initWithFrame:CGRectMake(0 ,100,self.view.frame.size.width,200)];
//添加到视图上展示
 [self.view addSubview:circle];