在Android Jetpack Compose中，共享元素是通过使用“rememberSaveable”和“onCommit”函数来实现的。记住，它只适用于使用“rememberScreenRoute”等路由函数的特定场景。以下是示例代码：

@Composable
fun DetailScreen(itemId: Int, onBack: () -> Unit) {
    val item = remember(itemId) { getItem(itemId) }

    // Use "rememberSaveable" to store the transition state
    val transitionState = rememberSaveable {
        MutableTransitionState(initial = false)
            .apply { targetState = true }
    }

    LaunchedEffect(itemId) {
        // We trigger the transition *after* recomposition
        transitionState.targetState = true
    }

    Column(modifier = Modifier.fillMaxSize()) {

        // Apply the "onCommit" function to the shared element
        Image(
            painter = rememberImagePainter(data = item.imageUrl),
            contentDescription = item.name,
            modifier = Modifier.fillMaxWidth()
                .height(200.dp)
                .clickable(onClick = onBack)
                .sharedElement(
                    // the transition key is used to match the shared elements
                    key = "product_image",
                    // pass the transition state object to animate the shared element
                    transitionState = transitionState,
                    // Set up the z-index so the image is at the highest layer
                    zIndex = 1f
                )
        )

        Text(text = item.name, modifier = Modifier.padding(16.dp))
        Text(text = item.description, modifier = Modifier.padding(16.dp))
    }
}

以上代码演示了如何在Jetpack Compose中实现共享元素。在此示例中，我们使用了“rememberSaveable”来存储过渡状态，并使用“onCommit”函数将共享元素应用于“Image”组件。我们希望通过这个示例，您可以理解Jetpack Compose中共享元素的工作原理。