360旋转动画
-(void)rote360Image{
CABasicAnimation *animation =[CABasicAnimation animationWithKeyPath:@"transform" ];
animation.fromValue = [NSValue valueWithCATransform3D:CATransform3DIdentity];
//圍繞z軸旋轉,垂直螢幕
animation.toValue =[NSValue valueWithCATransform3D:CATransform3DMakeRotation(M_PI, 0, 0, 1.0)];
animation.duration = 3;
//旋轉效果累計,先轉180度,接著再旋轉180度,從而實現360度旋轉
animation.cumulative = YES;
animation.repeatCount = 2;
//在圖片邊緣新增一個像素的透明區域,去圖片鋸齒
CGRect imageRrect = CGRectMake(0, 0,self.splashImageView.frame.size.width, self.splashImageView.frame.size.height);
UIGraphicsBeginImageContext(imageRrect.size);
[self.splashImageView.image drawInRect:CGRectMake(1,1,self.splashImageView.frame.size.width-2,self.splashImageView.frame.size.height-2)];
self.splashImageView.image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
[self.splashImageView.layer addAnimation:animation forKey:nil];
}