Android Compose 控件学习十三（一种牛拜的多窗口显示方法）

1.说明

采用将各窗口的Compose 作为参数传入，然后按需调用，可以实现多窗口的切换显示。

2.代码

@Composable
fun MenusExamples() {
    var currentExample by remember { mutableStateOf<(@Composable () -> Unit)?>(null) }

    Box(modifier = Modifier.fillMaxSize()) {
        currentExample?.let {
            it()
            FloatingActionButton(
                onClick = { currentExample = null },
                modifier = Modifier
                    .align(Alignment.BottomEnd)
                    .padding(16.dp)
            ) {
                Text(text = "Close example", modifier = Modifier.padding(16.dp))
            }
            return
        }

        Column(modifier = Modifier.padding(16.dp)) {
            Button(onClick = { currentExample = { MinimalDropdownMenu() } }) {
                Text("Minimal dropdown menu")
            }
            Button(onClick = { currentExample = { LongBasicDropdownMenu() } }) {
                Text("Dropdown menu with many items")
            }
            Button(onClick = { currentExample = { DropdownMenuWithDetails() } }) {
                Text("Dropdown menu with sections and icons")
            }
            Button(onClick = { currentExample = { DropdownFilter() } }) {
                Text("Menu for applying a filter, attached to a filter chip")
            }
        }
    }
}

其中的 MinimalDropdownMenu...为一个无参数的compose。这里不再给出相应代码。