iOS Dev (28) 三種基本的 2D 放射變換

• 基礎

  我們要用到的是：

  CGAffineTransform
  

  的一些函數（是 C 形式的函數）。

  縮放 scale 的定義：

  CGAffineTransform CGAffineTransformScale (
     CGAffineTransform t,
     CGFloat sx,
     CGFloat sy
  );
  

  旋轉 roate 的定義：

  CGAffineTransform CGAffineTransformRotate (
     CGAffineTransform t,
     CGFloat angle
  );
  

  平移 translate 的定義：

  CGAffineTransform CGAffineTransformTranslate (
     CGAffineTransform t,
     CGFloat tx,
     CGFloat ty
  );
  

  示例

  建立一個 Empty Project，直接該丫的 application 方法。

  - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
  {
      self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
  
      UIView *view1 = [[UIView alloc] initWithFrame:CGRectMake(60, 100, 200, 200)];
      view1.tag = 101;
      view1.backgroundColor = [UIColor redColor];
      [self.window addSubview:view1];
  
      UIView *view2 = [[UIView alloc] initWithFrame:CGRectMake(50, 50, 100, 100)];
      view2.tag = 102;
      view2.backgroundColor = [UIColor yellowColor];
      [view1 addSubview:view2];
  
      UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(110, 400, 100, 44)];
      btn.backgroundColor = [UIColor cyanColor];
      [btn addTarget:self action:@selector(onClick) forControlEvents:UIControlEventTouchUpInside];
      [self.window addSubview:btn];
  
      self.window.backgroundColor = [UIColor whiteColor];
      [self.window makeKeyAndVisible];
      return YES;
  }
  
  - (void)onClick
  {
      UIView *view2 = [[self.window viewWithTag:101] viewWithTag:102];
      view2.transform = CGAffineTransformScale(view2.transform, 0.8, 0.8);
      view2.transform = CGAffineTransformRotate(view2.transform, 0.2);
      view2.transform = CGAffineTransformTranslate(view2.transform, 50, 50);
  }
  

  -

  轉載請注明來自：http://blog.csdn.net/prevention