CGAffineTransform

//移动效果
CGAffineTransform CGAffineTransformMakeTranslation (    CGFloat tx,    CGFloat ty );CGAffineTransform CGAffineTransformTranslate (    CGAffineTransform t,    CGFloat tx,    CGFloat ty );//旋转效果
CGAffineTransform CGAffineTransformMakeRotation (    CGFloat angle );CGAffineTransform CGAffineTransformRotate (    CGAffineTransform t,    CGFloat angle );//缩放效果
CGAffineTransform CGAffineTransformMakeScale (    CGFloat sx,    CGFloat sy );CGAffineTransform CGAffineTransformScale (    CGAffineTransform t,    CGFloat sx,    CGFloat sy );//反转效果
CGAffineTransform CGAffineTransformInvert (    CGAffineTransform t );//只对局部产生效果
CGRect CGRectApplyAffineTransform (    CGRect rect,    CGAffineTransform t );//判断两个AffineTrans是否相等
bool CGAffineTransformEqualToTransform (    CGAffineTransform t1,    CGAffineTransform t2 );//获得Affine Transform
CGAffineTransform CGContextGetUserSpaceToDeviceSpaceTransform (    CGContextRef c );//下面的函数只起到查看的效果，比如看一下这个用户空间的点，转换到设备空间去坐标是多少CGPoint CGContextConvertPointToDeviceSpace (    CGContextRef c,    CGPoint point );CGPoint CGContextConvertPointToUserSpace (    CGContextRef c,    CGPoint point );CGSize CGContextConvertSizeToDeviceSpace (    CGContextRef c,    CGSize size );CGSize CGContextConvertSizeToUserSpace (    CGContextRef c,    CGSize size );CGRect CGContextConvertRectToDeviceSpace (    CGContextRef c,    CGRect rect );CGRect CGContextConvertRectToUserSpace (    CGContextRef c,    CGRect rect );

 

了解动画需要先了解仿射变换,先在View中添加一个按钮和一个图片, 通过这演示常见的变换,直接上码：

#import "ViewController.h"#define M_PI        3.14159265358979323846264338327950288

#define M_PI_2      1.57079632679489661923132169163975144

#define M_PI_4      0.785398163397448309615660845819875721
@interface ViewController ()
{UIButton *btn;UIImageView *imgview;
}
@end@implementation ViewController- (void)viewDidLoad {[super viewDidLoad];btn=[UIButton buttonWithType:UIButtonTypeSystem];btn.frame=CGRectMake(30, 30, 50, 50);btn.backgroundColor=[UIColor redColor];[btn setTitle:@"按钮" forState:UIControlStateNormal];[btn addTarget:self action:@selector(btnclick:) forControlEvents:UIControlEventTouchUpInside];[self.view addSubview:btn];imgview=[[UIImageView alloc]initWithImage:[UIImage imageNamed:@"test.jpg"]];imgview.frame=CGRectMake(100, 100, 120, 120);[self.view addSubview:imgview];}

 

 一.平移变换,当我实验平移时，将下面代码放在按钮点击方法中,第一个方法第一次点击有效，第二个是每次点击都会平移，第三个不会平移

 //平移变换imgview.transform=CGAffineTransformMakeTranslation(10, 10); //每次移动参照点都是初始点imgview.transform=CGAffineTransformTranslate(imgview.transform, 20, 20);//平移参照第一个参数的点imgview.transform=CGAffineTransformIdentity;//初始点

 二、旋转

 //旋转imgview.transform=CGAffineTransformMakeRotation(M_PI/4);//旋转参照初始值 正数顺时针 负数逆时针imgview.transform=CGAffineTransformRotate(imgview.transform, -M_PI/4);//旋转参照第一个参数的值

 三、缩放

// 缩放imgview.transform=CGAffineTransformScale(imgview.transform,0.8,0.8);//在第一个参数的基础上缩放 第二三参数1时为正常大小imgview.transform=CGAffineTransformMakeScale(0.5,0.5);//在原视图的基础上缩放

 四、翻转

//翻转// CGAffineTransform DefaultAffineTransform =CGAffineTransformMake(1, 0, 0, 1, 0, 0);//默认// imgview.transform=CGAffineTransformInvert(imgview.transform); //调用此行代码并不会产生翻转效果,因为恒等矩阵＊恒等矩阵还是恒等矩阵，这样就没有变化CGAffineTransform AffineTransform =CGAffineTransformMake(0, 1, 1, 1, 1, 0);imgview.transform=CGAffineTransformInvert(AffineTransform);

五、合并

//合并 将两个仿射合并成一个仿射效果
//    CGAffineTransform AffineTransform1 =CGAffineTransformMakeScale(0.5,0.5);CGAffineTransform AffineTransform1=CGAffineTransformScale(imgview.transform,0.8,0.8);CGAffineTransform AffineTransform2 =CGAffineTransformMakeRotation(M_PI/4);CGAffineTransform AffineTransform3=CGAffineTransformConcat(AffineTransform1,AffineTransform2);CGAffineTransform AffineTransform4 =CGAffineTransformMake(0, 1, 1, 1, 1, 0);imgview.transform=CGAffineTransformConcat(AffineTransform3,AffineTransform4);

 六、判断是否相同

 CGAffineTransform DefaultAffineTransform =CGAffineTransformMake(1, 0, 0, 1, 0, 0);CGAffineTransform DefaultAffineTransform1 =CGAffineTransformMake(1, 0, 0, 1, 0, 0);
//      CGAffineTransform AffineTransform1 =CGAffineTransformMakeScale(0.5,0.5);bool flag=CGAffineTransformEqualToTransform(DefaultAffineTransform, DefaultAffineTransform1);NSLog(@"%d",flag);