iOS开发 -------- transform属性(形变)

一 transform属性

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在OC中,通过transform属性可以修改对象的平移,比例和旋转角度

常用的创建transform结构体的方法分两大类

(1) 创建"基于控件初始位置"的形变

CGAffineTransformMakeTranslation (平移)

CGAffineTransformMakeScale (缩放)

CGAffineTransformMakeRotation (旋转)

(2) 创建"基于transform参数"的形变

CGAffineTransformTranslate

CGAffineTransformScale

CGAffineTransformRotate

在OC中,所有跟角度相关的数值,都是弧度值,180º = M_PI

正数表示顺时针旋转

负数代表逆时针旋转

二 代码示例

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 //
 //  RootViewController.m
 //  练习使用按钮的frame和center属性
 //
 //  Created by lovestarfish on 15/11/1.
 //  Copyright © 2015年 S&G. All rights reserved.
 //

 #import "RootViewController.h"

 @interface RootViewController ()

 @property (nonatomic,retain) UIButton *headImageView;

 @end

 @implementation RootViewController

 - (void)dealloc {
     self.headImageView = nil;
     [super dealloc];
 }

 //枚举类型,从1开始
 //枚举类型有一个很大的作用,就是用来代替程序中的魔法数字
 typedef enum {
     ktopbtntag = ,
     kdownbtntag,
     kleftbtntag,
     krightbtntag
 }btntag;

 /**
  *  viewDidLoad是视图加载完成后调用的方法,通常在此方法中执行视图控制器的初始工作
  */
 - (void)viewDidLoad {

     //在viewDidLoad方法中,不要忘记调用父类的方法实现
     [super viewDidLoad];

     self.title = @"按钮的frame和center属性";

     //一 手写控件代码
     //1.使用类创建一个按钮对象,设置按钮对象为自定义型
     UIButton *headBtn = [UIButton buttonWithType:UIButtonTypeCustom];

     //2.设置对象的各项属性
     //(1)位置等通用属性设置
     headBtn.frame = CGRectMake(137.5, , , );

     //(2)设置普通状态下按钮的属性
     [headBtn setBackgroundImage:[UIImage imageNamed:@"xib1"] forState:UIControlStateNormal];
     [headBtn setTitle:@"点我" forState:UIControlStateNormal];
     [headBtn setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];

     //(3)设置高亮状态下按钮的属性
     [headBtn setBackgroundImage:[UIImage imageNamed:@"xib2"] forState:UIControlStateHighlighted];
     [headBtn setTitle:@"还行吧" forState:UIControlStateHighlighted];
     [headBtn setTitleColor:[UIColor redColor] forState:UIControlStateHighlighted];

     //3.把对象添加到视图中展现出来
     [self.view addSubview:headBtn];
     self.headImageView = headBtn;

     //二 写四个控制图片上下左右移动方向的控制按钮
     //向上
     UIButton *topBut = [UIButton buttonWithType:UIButtonTypeSystem];
     topBut.frame = CGRectMake(167.5, , , );
     [topBut setTitle:@"向上" forState:UIControlStateNormal];
     topBut.tag = ;
     [topBut addTarget:self action:@selector(click:) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:topBut];

     //向下
     UIButton *downBtn = [UIButton buttonWithType:UIButtonTypeSystem];
     downBtn.frame = CGRectMake(167.5, , , );
     [downBtn setTitle:@"向下" forState:UIControlStateNormal];
     downBtn.tag = ;
     [downBtn addTarget:self action:@selector(click:) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:downBtn];

     //向左
     UIButton *leftBtn = [UIButton buttonWithType:UIButtonTypeSystem];
     leftBtn.frame = CGRectMake(, , , );
     [leftBtn setTitle:@"向左" forState:UIControlStateNormal];
     leftBtn.tag = ;
     [leftBtn addTarget:self action:@selector(click:) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:leftBtn];

     //向右
     UIButton *rightBtn = [UIButton buttonWithType:UIButtonTypeSystem];
     rightBtn.frame = CGRectMake(, , , );
     [rightBtn setTitle:@"向右" forState:UIControlStateNormal];
     rightBtn.tag = ;
     [rightBtn addTarget:self action:@selector(click:) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:rightBtn];

     //三 写两个缩放按钮
     //放大
     UIButton *plusBtn = [UIButton buttonWithType:UIButtonTypeSystem];
     plusBtn.frame = CGRectMake(, , , );
     [plusBtn setTitle:@"放大" forState:UIControlStateNormal];
     plusBtn.tag = ;
     [plusBtn addTarget:self action:@selector(zoom:) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:plusBtn];
     //缩小
     UIButton *minusBtn = [UIButton buttonWithType:UIButtonTypeSystem];
     minusBtn.frame = CGRectMake(, , , );
     [minusBtn setTitle:@"缩小" forState:UIControlStateNormal];
     minusBtn.tag = ;
     [minusBtn addTarget:self action:@selector(zoom:) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:minusBtn];

     //向左旋转按钮
     UIButton *leftRotateBtn = [UIButton buttonWithType:UIButtonTypeSystem];
     leftRotateBtn.frame = CGRectMake(137.5, , , );
     [leftRotateBtn setTitle:@"向左旋转" forState:UIControlStateNormal];
     leftRotateBtn.tag = ;
     [leftRotateBtn addTarget:self action:@selector(rotate:) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:leftRotateBtn];
     //向右旋转按钮
     UIButton *rightRotateBtn = [UIButton buttonWithType:UIButtonTypeSystem];
     rightRotateBtn.frame = CGRectMake(137.5, , , );
     [rightRotateBtn setTitle:@"向右旋转" forState:UIControlStateNormal];
     rightRotateBtn.tag = ;
     [rightRotateBtn addTarget:self action:@selector(rotate:) forControlEvents:UIControlEventTouchUpInside];
     [self.view addSubview:rightRotateBtn];

 }

 /**
  *  控制方向的多个按钮调用同一个方法
  */
 - (void)click:(UIButton *)button {
     CGPoint center = self.headImageView.center;
     switch (button.tag) {
         case ktopbtntag:
             center.y -= ;
             break;
         case kdownbtntag:
             center.y += ;
             break;
         case kleftbtntag:
             center.x -= ;
             break;
         case krightbtntag:
             center.x += ;
             break;
         default:
             break;
     }
     //设置首尾动画
     [UIView beginAnimations:nil context:nil];
     self.headImageView.center = center;
     //设置时间
     [UIView setAnimationDuration:2.0];
     [UIView commitAnimations];
     NSLog(@"移动!");
 }

 /**
  *  缩放
  */
 - (void)zoom:(UIButton *)button {
     //使用frame,以自己的左上角(自己的原点)为原点
     /*
     CGRect frame = self.headImageView.frame;
     if (button.tag) {
         frame.size.height += 30;
         frame.size.width += 30;
     } else {
         frame.size.width -= 50;
         frame.size.height -= 50;
     }
     self.headImageView.frame = frame;
     */

     //使用bounds,以中心点为原点进行缩放
     CGRect bounds = self.headImageView.bounds;
     if (button.tag) {
         bounds.size.height += ;
         bounds.size.width += ;
     } else {
         bounds.size.height -= ;
         bounds.size.width -= ;
     }

     //设置首尾动画
     [UIView beginAnimations:nil context:nil];
     self.headImageView.bounds = bounds;
     [UIView setAnimationDuration:2.0];
     [UIView commitAnimations];
 }

 /**
  *  旋转
  */
 - (void)rotate:(UIButton *)button {
     //位移(不累加)
 //    self.headImageView.transform = CGAffineTransformMakeTranslation(50, 200);
     //缩放
 //    self.headImageView.transform = CGAffineTransformMakeScale(1.2, 0.5);
     //在原有的基础上位移(是累加的)
 //    self.headImageView.transform = CGAffineTransformTranslate(self.headImageView.transform, 50, 50);
     //在原有的基础上进行缩放
 //    self.headImageView.transform = CGAffineTransformScale(self.headImageView.transform, 1.5, 2.0);

     //在原有的基础上进行旋转
     if (button.tag) {
         //旋转的角度为1/pi,逆时针
         self.headImageView.transform = CGAffineTransformRotate(self.headImageView.transform, -M_1_PI);
     } else {
         //旋转的角度为pi/2,顺时针
         self.headImageView.transform = CGAffineTransformRotate(self.headImageView.transform, M_PI_2);
     }

 }

 - (void)didReceiveMemoryWarning {
     [super didReceiveMemoryWarning];
 }

 @end

三 实现效果

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