iOS-实现简单的动画效果 - 梦之奈落

ios中最简单的动画效果，是没有关键帧的，比如左右移动、上下跳动、旋转和缩放。关键帧要稍微复杂一点，要设置路径等。

iOS可以在不借助OpenGL 2D等重型库的情况下实现上述简单的动画效果。编写起来十分简单。

左右移动

上下移动的情况类似。

代码如下：

- (void)loadView {
    [[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation: UIStatusBarAnimationSlide];
    UIImage *image=[UIImage imageNamed:@"1.jpg"];
 
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(NULL, 768, 1024, 8, 4 * 768, colorSpace, kCGImageAlphaPremultipliedFirst);
    CGRect rect = CGRectMake(0, 0, 768, 1024);
    CGColorRef fillColor = [[UIColor whiteColor] CGColor];
    CGContextSetFillColor(context, CGColorGetComponents(fillColor));
 
    CGContextMoveToPoint(context, 160.0f, 230.0f);
    CGContextAddLineToPoint(context, 600.0f, 230.0f);
    CGContextAddLineToPoint(context, 600.0f, 100.0f);
    CGContextAddLineToPoint(context, 370.0f, 50.0f);
    CGContextAddLineToPoint(context, 200.0f, 100.0f);
 
    CGContextClosePath(context);
    CGContextClip(context);
    CGContextDrawImage(context, rect, image.CGImage);
    CGImageRef imageMasked = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    UIImage *newImage = [UIImage imageWithCGImage:imageMasked];
    CGImageRelease(imageMasked);
 
    UIImageView *backView=[[UIImageView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
    self.view=[[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
    [self.view addSubview:backView];
    backView.image=newImage;
    backView.alpha=0.3;
 
    CABasicAnimation *theAnimation1;    //定义动画
 
    //左右摇摆
    theAnimation1=[CABasicAnimation animationWithKeyPath:@"transform.translation.x"];
    theAnimation1.fromValue=[NSNumber numberWithFloat:0];
    theAnimation1.toValue=[NSNumber numberWithFloat:-100];
 
    theAnimation1.duration=5.5;//动画持续时间
    theAnimation1.repeatCount=6;//动画重复次数
    theAnimation1.autoreverses=YES;//是否自动重复
 
    [backView.layer addAnimation:theAnimation1 forKey:@"animateLayer"];
 
    [newImage release];
    [image release];
}

旋转

效果类似这样：

这里，图做了pi（180°）的旋转。只需把动画部分代码替换为：

1 2	theAnimation1=[CABasicAnimation animationWithKeyPath:@"transform"]; theAnimation1.toValue = [ NSValue valueWithCATransform3D: CATransform3DMakeRotation(3.1415, 0, 0, 1.0) ];

缩放

缩放类似这样：

代码可替换为：

1 2	theAnimation1=[CABasicAnimation animationWithKeyPath:@"transform.scale"]; theAnimation1.toValue = [NSNumber numberWithDouble:1.5];

原文链接：http://marshal.easymorse.com/archives/3727

转载编辑： Fgamers

转载地址：http://disanji.net/2010/12/18/ios-realize-animation-effect/