CGAffineTransform缩放、旋转、平移、还原

    //缩放

    //在原来的基础上进行缩放-->每一次都会缩放0.5倍

    view.transform =CGAffineTransformScale(t, 0.5, 0.5);

    //在原始的基础上进行缩放-->只会缩放一次

    view.transform =CGAffineTransformMakeScale(0.5,0.5);

    

    //旋转

    view.transform =CGAffineTransformRotate(t, M_PI/4);

    view.transform =CGAffineTransformMakeRotation(M_PI /4);

    

    //平移

    view.transform =CGAffineTransformTranslate(t, 50, 50);

    view.transform =CGAffineTransformMakeTranslation(50,50);

   //还原为最初的transform

    view.transform =CGAffineTransformIdentity;