协程 Kotlin

private val SPLASH_SCREEN_TIME_OUT_CONST: Long = 3000

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_splash)
    window.setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN
    )
    GlobalScope.launch {
        delay(SPLASH_SCREEN_TIME_OUT_CONST)
        goToIntro()
    }

}

private fun goToIntro(){
    startActivity(Intent(this, IntroActivity::class.java))
    finish()
}

在Kotlin中使用这种结构是个好主意

companion object Run {
   fun after(delay: Long, process: () -> Unit) {
      Handler(Looper.getMainLooper()).postDelayed({
          process()
      }, delay)
   }
}

稍后称为

Run.after(SPLASH_TIME_OUT) {
   val action = SplashFragmentDirections.actionSplashFragmentToLogin()
   v.findNavController().navigate(action)
}

考虑使用协程

scope.launch {
    delay(3000L)
    // do stuff
}

根据文档(https://developer.android.com/reference/android/os/Handler#Handler()):

Implicitly choosing a Looper during Handler construction can lead to bugs where operations are silently lost (if the Handler is not expecting new tasks and quits), crashes (if a handler is sometimes created on a thread without a Looper active), or race conditions, where the thread a handler is associated with is not what the author anticipated. Instead, use an Executor or specify the Looper explicitly, using Looper#getMainLooper, {link android.view.View#getHandler}, or similar. If the implicit thread local behavior is required for compatibility, use new Handler(Looper.myLooper()) to make it clear to readers.

我们应该停止使用没有Looper的构造函数，而是指定一个Looper。

如果你想避免在Kotlin (?或者!!)你可以使用loop . getmainlooper()如果你的Handler正在处理一些UI相关的事情，像这样:

Handler(Looper.getMainLooper()).postDelayed({
   Toast.makeText(this@MainActivity, "LOOPER", Toast.LENGTH_SHORT).show()
}, 3000)

注意:如果使用fragment，请使用requireContext()而不是this@MainActivity。

在Handler构造函数中提供一个循环器

Handler(Looper.getMainLooper())