我正在创建一个带有导航抽屉的应用程序。一切顺利,我已经添加了我的菜单文件抽屉头文件。但是当我在 MainActivity 文件中编写逻辑代码时,我在 Android 清单文件的“.MainActivity”位置收到错误。
错误是“未解析的类‘MainActivity’”
代码: 类 MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelectedListener { private Lateinit var抽屉布局:DrawerLayout
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
drawerLayout = findViewById<DrawerLayout>(R.id.drawer_layout)
val toolbar = findViewById<Toolbar>(R.id.toolbar)
setSupportActionBar(toolbar)
val navigationView = findViewById<NavigationView>(R.id.nav_view)
navigationView.setNavigationItemSelectedListener(this)
val toggle = ActionBarDrawerToggle(this, drawerLayout, toolbar, R.string.open_nav, R.string.close_nav)
drawerLayout.addDrawerListener(toggle)
toggle.syncState()
if (savedInstanceState == null) {
supportFragmentManager.beginTransaction()
.replace(R.id.fragment_container, HomeFragement()).commit()
navigationView.setCheckedItem(R.id.nav_general)
}
}
override fun onNavigationItemSelected(item: MenuItem): Boolean {
when (item.itemId) {
R.id.nav_general -> supportFragmentManager.beginTransaction()
.replace(R.id.fragment_container, HomeFragement()).commit()
R.id.nav_pred -> supportFragmentManager.beginTransaction()
.replace(R.id.fragment_container, MLFragment()).commit()
R.id.nav_safety -> supportFragmentManager.beginTransaction()
.replace(R.id.fragment_container, SafetyFragment()).commit()
R.id.nav_about -> supportFragmentManager.beginTransaction()
.replace(R.id.fragment_container, AboutFragment()).commit()
R.id.nav_logout -> Toast.makeText(this, "Logout!", Toast.LENGTH_SHORT).show()
}
drawerLayout.closeDrawer(GravityCompat.START)
return true
}
override fun onBackPressed() {
if (drawerLayout.isDrawerOpen(GravityCompat.START)) {
drawerLayout.closeDrawer(GravityCompat.START)
} else {
onBackPressedDispatcher.onBackPressed()
}
}
}
我尝试删除该文件并创建另一个文件,但我遇到了同样的问题