创建动画

1.动画（头部-开始动画）
[UIView beginAnimations:nil context:nil];2.设置动画的执行时间
[UIView setAnimationDuration:1.0];3.向上移动// CGPoint tempCenter = _btn.center;
CGRect tempFrame = _btn.frame;tempFrame.origin.y -= 50;_btn.frame = tempFrame;  3.左旋转45°   (transfrom 变形,改造)//_btn.transfrom = CGAffineTransformMakeROtation(- M_PI_4);

_btn.transform = CGAffineTransformRotate(_btn.transform,- M_PI_4);4.变大//_btn.transform = CGAffineTransformMakeScale(1.2, 1.2);
_btn.transform = CGAffineTransformScale(_btn.transform, 1.2, 1.2);5.透明度 (0-1)
_ben.alpha = 1;6.动画（尾巴-提交动画-执行动画）
[UIView commitAnimations];//清空之前所有的形变状态（消除以前的旋转、缩放等状态）
_btn.transform = CGAffineTransformIdentity;方法二：
[UIView animateWithDuration:1.0 animations:^{rowView.frame = CGRectMake(0,20,100,40);rowView.alpha = 1;
}];[UIView animateWithDuration:1.0 animations:^{rowView.frame = CGRectMake(0,20,100,40);rowView.alpha = 1;
} completion:^(BOOL finished){ //动画执行完毕后会自动调用这个block
    NSLog(@“哈哈”);
}];