java - 尝试声明 BottomNavigationView

Question

我是 Kotlin 开发新手。我正在尝试执行 BottomNavigationView，一切正常，但是当我想为 ItemSelected Listener 创建 BottomNavigationView 变量时，出现以下错误:

Function invocation 'BottomNavigationView(...)' expected.

但在我的教程中它是这样声明的:BottomNavigationView BottomNav

怎么了，我不明白..你能帮我一下吗？

Answer 1

为bottomViewListener声明一个全局变量

'onNavigationItemSelectedListener'

在onCreate()中初始化并设置bottomView中的监听器

val navView: BottomNavigationView = findViewById(R.id.nav_view) navView.setOnNavigationItemSelectedListener(onNavigationItemSelectedListener)

private val onNavigationItemSelectedListener = BottomNavigationView.OnNavigationItemSelectedListener { item ->
        when (item.itemId) {
            R.id.navigation_home -> {
                return@OnNavigationItemSelectedListener true
            }
            R.id.navigation_deals -> {
                return@OnNavigationItemSelectedListener true
            }

        }
        false
    }