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AnimatedVisibility中的EnterTransition 和 ExitTransition ,用来配置入场/出场时候的动画效果。
默认的入场效果是 fadeIn() + expandVertically()
默认的出场效果是 fadeOut() + shrinkVertically()
1. EnterTransition和ExitTransition支持的动画
enter的参数类型是EnterTransition,支持这些动画
- 淡入 :
fade: fadeIn - 缩放 :
scale: scaleIn - 滑动 :
slide: slideIn, slideInHorizontally, slideInVertically - 展开 :
expand: expandIn, expandHorizontally, expandVertically
exit的参数类型是EnterTransition,支持这些动画
- 淡出 :
fade: fadeOut - 缩放 :
scale: scaleOut - 滑动 :
slide: slideOut, slideOutHorizontally, slideOutVertically - 收缩 :
shrink: shrinkOut, shrinkHorizontally, shrinkVertically
可以看到EnterTransition和ExitTransition支持的动画只有expand和shrink命名上有区别,
其他都是对应的 fadeIn 和 fadeOut,scaleIn 和 scaleOut,slideIn 和 slideOut。
expand和shrink命名上做区分,是因为expand就是展开的意思,而shrink是收缩的意思,它们其实就是相对应的。
2. fadeIn / fadeOut
fadeIn / fadeOut是淡出淡出的效果
我们使用上篇文章中的那段代码
@Composable
fun AnimatedVisibilityPage() {Column(horizontalAlignment = Alignment.CenterHorizontally) {var visible by remember {mutableStateOf(true)}AnimatedVisibility(visible = visible) {MyImage()}Spacer(modifier = Modifier.height(10.dp))Button(onClick = { visible = !visible }) {Text(text = "显示/隐藏")}}
}@Composable
private fun MyImage() {Image(painter = painterResource(id = R.mipmap.photot1),modifier = Modifier.width(300.dp),contentDescription = null)
}
然后修改AnimatedVisibility,配置enter和exit
AnimatedVisibility(visible = visible,enter = fadeIn(),exit = fadeOut()
) {MyImage()
}
效果如下所示

3. scaleIn / scaleOut
scaleIn / scaleOut是缩放的效果
AnimatedVisibility(visible = visible,enter = scaleIn(),exit = scaleOut()
) {MyImage()
}
效果如下所示

4. slideIn / SlideOut
slideIn / SlideOut是滑动的效果,这里进入的初始位置和退出的目标位置都设置为了(300,-150),所以会从右上角进入/退出
AnimatedVisibility(visible = visible,enter = slideIn(initialOffset = {IntOffset(300, -150) }),exit = slideOut(targetOffset = {IntOffset(300,-150) })
) {MyImage()
}
效果如下所示

5. slideInVertically / slideOutVertically
slideInVertically / slideOutVertically是垂直方向滑动进入/退出
AnimatedVisibility(visible = visible,enter = slideInVertically(),exit = slideOutVertically()
) {MyImage()
}
效果如下所示

5.1 slideInHorizontally / slideOutHorizontally
slideInHorizontally / slideOutHorizontally是从横向方向滑动进入/退出
AnimatedVisibility(visible = visible,enter = slideInHorizontally(),exit = slideOutHorizontally()
) {MyImage()
}
效果如下所示

6. expandIn / shrinkOut
expandIn / shrinkOut是展开/收缩的效果
AnimatedVisibility(visible = visible,enter = expandIn(),exit = shrinkOut()
) {MyImage()
}
效果如下所示

6.1 expandVertically / shrinkVertically
expandVertically / shrinkVertically是从垂直方向展开/收缩
AnimatedVisibility(visible = visible,enter = expandVertically(),exit = shrinkVertically()
) {MyImage()
}
效果如下所示

6.2 expandHorizontally / shrinkHorizontally
expandHorizontally / shrinkHorizontally是从横向方向展开/收缩
AnimatedVisibility(visible = visible,enter = expandHorizontally(),exit = shrinkHorizontally()
) {MyImage()
}
效果如下所示

7. 其他
7.1 Compose动画系列
Compose 动画系列,后续持续更新,可以先关注
Compose 动画 (一) : animateXxxAsState 实现放大/缩小/渐变等效果
Compose 动画 (二) : 为什么animateDpAsState要用val ? MutableState和State有什么区别 ?
Compose 动画 (三) : AnimatedVisibility 从入门到深入
7.2 参考
关于EnterTransition 和 ExitTransition 示例也可以看这里
