Question

我是核心动画的新手。每当我调用动画时，我的图像从其位置移动到屏幕的左上角，移动，然后返回到原始位置。如何使图像向左移动50个单位，停止，如果再次按下该按钮则重复。代码：

-(IBAction)preform:(id)sender{

CGPoint point = CGPointMake(50, 50);

CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:@"position"];
anim.fromValue  = [NSValue valueWithCGPoint:point];
anim.toValue    = [NSValue valueWithCGPoint:CGPointMake(point.x + 50, point.y)];
anim.duration   = 1.5f;
anim.repeatCount =1;
anim.removedOnCompletion = YES;
anim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
[imView.layer  addAnimation:anim forKey:@"position"];

}

Answer 1

对于您的情况，您可以跳过重型CA机器并使用块动画

// Your image is at starting position
[UIView animateWithDuration:1.5 animations:^{
        CGRect newFrame = CGRectOffset(imView.frame, 50, 0);
        imView.frame = newFrame;
    }];

但是，如果您想知道如何正确处理此“快照”，请检查this url。

调用动画后，UIImage视图会重置

1 个答案: