推断类型为 DashboardFragment.Companion 但 Fragment 应在函数 replaceFragment 中

Question

private val dashboardFragment = DashboardFragment
private val settingsFragment = SettingsFragment
private val infoFragment = InfoFragment

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    binding = ActivityHomePageBinding.inflate(layoutInflater)
    setContentView(binding?.root)

    replaceFragment(dashboardFragment)

}

private fun replaceFragment(fragment: Fragment){
    if(fragment != null){
        val transaction = supportFragmentManager.beginTransaction()
        transaction.replace(R.id.frag_container, fragment)
        transaction.commit()
    }
}

我的项目中设置了 3 个片段，即仪表板、设置和信息。每次我在函数 replaceFragment 中输入我的片段名称时，我都会收到类型不匹配的错误。我指的是这个视频 - https://www.youtube.com/watch?v=v8MbOjBCu0o&t=1s

Answer 1

您需要实例化这些字段。现在他们只是指向 class 类型。它类似于 java 中的 new 关键字。

private val dashboardFragment = DashboardFragment()
private val settingsFragment = SettingsFragment()
private val infoFragment = InfoFragment()

推断类型为 DashboardFragment.Companion 但 Fragment 应在函数 replaceFragment 中

inferred type is DashboardFragment.Companion but Fragment was expected in function replaceFragment

android

kotlin

fragment