使用按钮更改图像位置

Question

我想用一个按钮在三个不同的位置改变图像的位置...用我的代码图像只移动了一个位置...

ViewController.h

@property (weak, nonatomic) IBOutlet UIImageView *Switch3Way;

- (IBAction)Switch3WayPressed:(id)sender;

ViewController.m

- (void)Switch3WayPressed:(id)sender {
CGRect frame = Switch3Way.frame;
frame.origin.x = 323;
frame.origin.y = 262;
Switch3Way.frame = frame;

}

Answer 1

下面的代码假设您希望对Switch3Way UIImageView IBOutlet属性进行动画化。此代码段将把您的UIImageView移动到三个不同的位置，并在最后一个位置停止动画。

#import <QuartzCore/QuartzCore.h>    

-(IBAction)move:(id)sender
{
    CGPoint firstPosition = CGPointMake(someXvalue, someYvalue);
    CGPoint secondPosition = CGPointMake(someXvalue, someYvalue);
    CGPoint thirdPosition  = CGPointMake(someXvalue, someYvalue);

    CABasicAnimation *posOne = [CABasicAnimation animationWithKeyPath:@"position"];
    posOne.fromValue = [NSValue valueWithCGPoint:_Switch3Way.layer.position];
    posOne.toValue   = [NSValue valueWithCGPoint:firstPosition];
    posOne.beginTime = 0;
    posOne.duration  = 1;

    CABasicAnimation *posTwo = [CABasicAnimation animationWithKeyPath:@"position"];
    posTwo.fromValue = [NSValue valueWithCGPoint:firstPosition];
    posTwo.toValue   = [NSValue valueWithCGPoint:secondPosition];
    posTwo.beginTime = 1;
    posTwo.duration  = 1;

    CABasicAnimation *posThree = [CABasicAnimation animationWithKeyPath:@"position"];
    posThree.fromValue = [NSValue valueWithCGPoint:secondPosition];
    posThree.toValue   = [NSValue valueWithCGPoint:thirdPosition];
    posThree.beginTime = 2;
    posThree.duration  = 1;

    CAAnimationGroup *anims = [CAAnimationGroup animation];
    anims.animations = [NSArray arrayWithObjects:posOne, posTwo, posThree, nil];
    anims.duration = 3;
    anims.fillMode = kCAFillModeForwards;
    anims.removedOnCompletion = NO;

    [_Switch3Way.layer addAnimation:anims forKey:nil];

    _Switch3Way.layer.position = thirdPosition;
}

Invasivecode有一个关于创建动画的非常好的系列教程，您可以参考http://weblog.Invasivecode.com/post/4448661320/core-animation-part-iii-basic-animations您最终会希望使用CAKeyframeAnimationhtml" target="_blank">对象来创建这些类型的动画，但是了解CABasicAnimations是开始使用coreanimation创建动画的一个好方法。