Flutter基建 - 12种隐式动画小组件全解析

在Flutter中，隐式动画是通过小部件的动画化来实现的，而不是显式地编写动画代码。Flutter提供了一些内置的动画小部件，如AnimatedContainer、SlideTransition、FadeTransition等，可以用来创建隐式动画。

以下是12种隐式动画小部件的简单示例：

1. AnimatedContainer:

AnimatedContainer(
  duration: Duration(seconds: 2),
  curve: Curves.fastOutSlowIn,
  width: size,
  height: size,
  decoration: BoxDecoration(
    borderRadius: BorderRadius.circular(16),
    color: color,
  ),
  child: child,
)

2. SlideTransition:

SlideTransition(
  position: Tween<Offset>(
    begin: const Offset(0, 1),
    end: const Offset(0, 0),
  ).animate(animation),
  child: child,
)

3. FadeTransition:

FadeTransition(
  opacity: animation,
  child: child,
)

4. RotationTransition:

RotationTransition(
  turns: Tween<double>(begin: 0, end: 1).animate(animation),
  child: child,
)

5. ScaleTransition:

ScaleTransition(
  scale: Tween<double>(begin: 0, end: 1).animate(animation),
  child: child,
)

6. AnimatedSwitcher:

AnimatedSwitcher(
  duration: const Duration(milliseconds: 300),
  transitionBuilder: (child, animation) {
    return FadeTransition(opacity: animation, child: child);
  },
  child: icon,
)

7. AnimatedList:

AnimatedList(
  key: listKey,
  initialItemCount: items.length,
  itemBuilder: (context, index, animation) {
    return SlideTransition(
      position: animation.drive(tween),
      child: ListItem(
        item: items[index],
        onDismissed: () {
          setState(() {
            items.removeAt(index);
          });
        },
      ),
    );
  },
)

8. ImplicitlyAnimatedListState:

ImplicitlyAnimatedList<int>(
  items: List<int>.generate(1000, (i) => i),
  itemBuilder: (context, index, animation) {
    return SizeTransition(
      sizeFactor: animation,
      child: ListItem(item: index),
    );
  },
)

9. AnimatedCrossFade:

AnimatedCrossFade(
  firstChild: firstWidget,
  secondChild: secondWidget,
  crossFadeState: crossFadeState,
  duration: const Duration(milliseconds: 300),
)

10. TweenAnimationBuilder:

TweenAnimationBuilder(
  tween: Tween<double>(begin: 0, end: 1),
  duration: const Duration(seconds: 2),
  builder: (BuildContext context, double value, Widget child) {
    return Transform.translate(
      offset: Offset.lerp(const Offset(0, 100), const Offset(0, 0), value),