UI基础-基础控件-0324-transform应用-使用transform实现btn小案例

利用transform属性可以修改控件的位移（位置）、缩放、旋转

创建一个transform属性
CGAffineTransform CGAffineTransformMakeTranslation(CGFloat tx,  CGFloat ty) ;
CGAffineTransform CGAffineTransformMakeScale(CGFloat sx, CGFloat sy);
CGAffineTransform CGAffineTransformMakeRotation(CGFloat angle)
(angle是弧度制，并不是角度制)

在某个transform的基础上进行叠加
CGAffineTransform CGAffineTransformTranslate(CGAffineTransform t, CGFloat tx, CGFloat ty);//平移
CGAffineTransform CGAffineTransformScale(CGAffineTransform t, CGFloat sx, CGFloat sy);//比例变化
CGAffineTransform CGAffineTransformRotate(CGAffineTransform t, CGFloat angle);//旋转

清空之前设置的transform属性
view.transform = CGAffineTransformIdentity;

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</pre><pre name="code" class="objc">#import "MJViewController.h"

@interface MJViewController ()
- (IBAction)leftRotate;
- (IBAction)up;
- (IBAction)big;
@end

@implementation MJViewController

- (IBAction)leftRotate {

*******************************************************************
// 1.取得头像按钮。。一种拖属性，第二种通过tag（只要在view中就可以，如果tag重复，优先原则）
UIButton *head = (UIButton *)[self.view viewWithTag:10];
********************************************************************
// 2.向左旋转45°
// 45  180
// 角度是正数:顺时针, 角度是负数:逆时针
//    head.transform = CGAffineTransformMakeRotation(-M_PI_4);
head.transform = CGAffineTransformRotate(head.transform, M_PI_4);
}

- (IBAction)up {
// 1.取得头像按钮
UIButton *head = (UIButton *)[self.view viewWithTag:10];

// 2.每次向上移动100的距离
//    head.transform = CGAffineTransformMakeTranslation(0, -100);
head.transform = CGAffineTransformTranslate(head.transform, 0, -100);
}

- (IBAction)big {
// 1.取得头像按钮
UIButton *head = (UIButton *)[self.view viewWithTag:10];

// 2.增大
//    head.transform = CGAffineTransformMakeScale(1.5, 1.5);
head.transform = CGAffineTransformScale(head.transform, 1.5, 1.5);
}
@end