ios开发基础知识 － 2

移动物体

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CABasicAnimation *theAnimation;    theAnimation=[CABasicAnimation animationWithKeyPath:@"transform.translation.x"]; theAnimation.duration=1; theAnimation.repeatCount=2; theAnimation.autoreverses=YES; theAnimation.fromValue=[NSNumber numberWithFloat:0]; theAnimation.toValue=[NSNumber numberWithFloat:-60]; [view.layer addAnimation:theAnimation forKey:@"animateLayer"];

参考：

Field Key Path	Description
rotation.x	The rotation, in radians, in the x axis.
rotation.y	The rotation, in radians, in the y axis.
rotation.z	The rotation, in radians, in the z axis.
rotation	The rotation, in radians, in the z axis. This is identical to setting the rotation.z field.
scale.x	Scale factor for the x axis.
scale.y	Scale factor for the y axis.
scale.z	Scale factor for the z axis.
scale	Average of all three scale factors.
translation.x	Translate in the x axis.
translation.y	Translate in the y axis.
translation.z	Translate in the z axis.
translation	Translate in the x and y axis. Value is an NSSize or CGSize.

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访问别的类的属性或者方法

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myAppDelegate *appDelegate      = (myAppDelegate *)[[UIApplication sharedApplication] delegate]; [[[appDelegate rootViewController] flipsideViewController] myMethod];

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遍历子视图

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for (UIImageView *anImage in [self.view subviews]) {      if (anImage.tag == 1) {           // do something      } }

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播放音乐

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// 设置音乐文件路径 path = [[NSBundle mainBundle] pathForResource:@"mani" ofType:@"mp3"];       // 判断是否可以访问这个文件 if ([[NSFileManager defaultManager] fileExistsAtPath:path]) {            // 设置 player     player = [[AVAudioPlayer alloc] initWithContentsOfURL:               [NSURL fileURLWithPath:path] error:nil];               // 调节音量 (范围从0到1)     player.volume = 0.4f;               // 准备buffer，减少播放延时的时间          [player prepareToPlay];               // 设置播放次数，0为播放一次，负数为循环播放     [player setNumberOfLoops:-1];           [player play];          }

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随机数

rand()

例：

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1 2	[_cloud02 setFrame:CGRectMake(-1024+rand()%600, -768+rand()%300, 2048, 1536)]; [_cloud01 setFrame:CGRectMake(-1024+rand()%600, -768+rand()%300, 2048, 1536)];

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Timer

每秒调用

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[NSTimer scheduledTimerWithTimeInterval:1      target:self      selector:@selector(myMethod)      userInfo:nil      repeats:YES];

如果需要传递参数的话：

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[NSTimer scheduledTimerWithTimeInterval:1     target:self      selector:@selector(myMethod)      userInfo:myObject      repeats:YES];

 

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-(void)myMethod:(NSTimer*)timer {      // Now I can access all the properties and methods of myObject      [[timer userInfo] myObjectMethod]; }

停止Timer

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1 2	[myTimer invalidate]; myTimer = nil;

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时间

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1	CFAbsoluteTime myCurrentTime = CFAbsoluteTimeGetCurrent();

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在模拟器里测试 App 的加速度感应功能

在模拟器里可以用鼠标点击模拟 iPhone 的触摸操作，但重力感应（比如用户倾斜机身来操控飞机/赛车）怎么模拟？按住 command 再按左右方向键，就能在电脑模拟器上测试加速度感应了。