如何修复Kotlin Android Studio 3.3中的“无法解析的引用”错误

时间：2019-02-24 23:03:59

标签： android kotlin android-studio-3.0

我是Kotlin和Andriod工作室的新手。我正在遵循一个教程，并且一切进展顺利，直到收到大量“未解决的参考错误”

我看过其他人关于这个问题的帖子，但是似乎仍然无济于事，因为我仍然收到多个错误

我尝试过：

  • 构建->清理->构建->重建。
  • 文件->使缓存无效并重新启动

  • 删除.idea / libraries-> File->使用Gradle文件同步项目。

    这是我的版本信息

    Android Studio 3.3.1 Build #AI-182.5107.16.33.5264788, built on January 28, 2019 JRE: 1.8.0_152-release-1248-b01 amd64 JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o Windows 10 10.0

我的代码 

package e.lakal.tapfighter

import android.content.ContentValues.TAG
import android.os.Bundle
import android.os.CountDownTimer
import android.os.PersistableBundle
import android.support.design.widget.Snackbar
import android.support.v7.app.AppCompatActivity
import android.util.Log
import android.view.Menu
import android.view.MenuItem
import android.widget.Button
import android.widget.TextView
import android.widget.Toast
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

internal lateinit var  tapmeButton: Button;
internal lateinit var GameScore: TextView;
internal lateinit var  Timer: TextView;
internal var  Score = 0
internal  var gameStarted = false

internal lateinit var countDownTimer : CountDownTimer
internal  val  initalCountDown: Long = 60000;
internal  val  CountDownInterval: Long = 1000;
internal val TAG = MainActivity::class.java.simpleName
internal val timeLeftonTimer : Long = 6000


companion object {
  private val SCORE_KEY ="SCORE_KEY"
  private val TIME_LEFT_KEY = "TIME_LEFT_KEY"
   }

override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_main)
    Log.d(TAG, "On create called. Score is $Score")
    setSupportActionBar(toolbar)

    fab.setOnClickListener { view ->
        Snackbar.make(view, "Replace with your own action", 
      Snackbar.LENGTH_LONG)
            .setAction("Action", null).show()
    }

    tapmeButton = findViewById<Button>(R.id.tapmeButton)
    GameScore = findViewById<TextView>(R.id.GameScore)
    Timer = findViewById<TextView>(R.id.Timer)
    GameScore.text = getString(R.string.YourScore, Score.toString())

  tapmeButton.setOnClickListener{  view ->
      incrementScore()
   }
    resetGame()
     }




private fun resetGame(){

    Score = 0
    GameScore.text = getString(R.string.YourScore, Score.toString())
    val initalTimeLeft = initalCountDown / 1000
    Timer.text = getString(R.string.TimeLeft, 
      initalTimeLeft.toString())

    countDownTimer =  object: CountDownTimer(initalCountDown, 
     CountDownInterval) {
        override fun onTick(millisUntilFinished: Long) {
           val  timeLeft = millisUntilFinished / 1000
            Timer.text = getString(R.string.TimeLeft, 
    timeLeft.toString())
        }

        override fun onFinish() {
         endGame()
        }
    }
 gameStarted =false;
}


  // Starts giving me problems here

}
 private fun startGame(){
    countDownTimer.start()
    gameStarted
 }


  override fun onSaveInstanceState(outState: Bundle?, 
  outPersistentState: PersistableBundle?) {
    super.onSaveInstanceState(outState, outPersistentState)

    outState?.putInt(SCORE_KEY, Score)
    outState?.putLong(TIME_LEFT_KEY, timeLeftonTimer)
    countDownTimer.cancel()

    Log.d(TAG,"onSaveInstanceState : Saving score : $Score & Saving 
 Time  current $timeLeftonTimer")

}
  override fun onDestroy(){
    super.onDestroy()
     Log.d(TAG, "onDestroy called.")
 }


private fun endGame(){
    Toast.makeText(this, getString(R.string.game_over_msg, Score.toString()), Toast.LENGTH_SHORT).show()
    resetGame()

}
private fun incrementScore() {
        if(!gameStarted){
            startGame() }
    Score++
    val newScore = getString(R.string.YourScore, Score.toString())
    GameScore.text = newScore
}



override fun onCreateOptionsMenu(menu: Menu): Boolean {

    menuInflater.inflate(R.menu.menu_main, menu)
    return true
}

override fun onOptionsItemSelected(item: MenuItem): Boolean {

    return when (item.itemId) {
        R.id.action_settings -> true
        else -> super.onOptionsItemSelected(item)
    }
}
}

Logcat 

019-02-24 17:49:13.359 2003-6170/? E/WakeLock: GCM_HB_ALARM release 
without a matched acquire!2019-02-24 17:49:13.450 1641-1769/? 
I/WifiService: getConnectionInfo uid=10013
2019-02-24 17:49:58.235 1641-1769/? D/WificondControl: Scan result 
 ready event
 2019-02-24 17:50:00.008 1641-1654/? E/memtrack: Couldn't load 
 memtrack module
 2019-02-24 17:50:00.008 1641-1654/? W/android.os.Debug: failed to 
 get memory consumption info: -1
 2019-02-24 17:50:00.016 1436-1454/? D/hwcomposer: hw_composer sent 
  6 syncs in 60s
 2019-02-24 17:50:00.111 1443-1443/? I/boot-pipe: done populating 
 /dev/random
 2019-02-24 17:50:15.532 1641-1658/? E/BatteryExternalStatsWorker: 
 modem info is invalid: ModemActivityInfo{ mTimestamp=0 
 mSleepTimeMs=0 mIdleTimeMs=0 mTxTimeMs[]=[0, 0, 0, 0, 0] 
  mRxTimeMs=0 mEnergyUsed=0}

编辑：通过在onCreate函数下移动onSaveInstanceState（）和onDestory解决了该问题

3 个答案:

答案 0 :(得分：0)

“ //在这里开始给我带来麻烦”的下方，方法的作用域是文件的根目录，而不是类的内部。

因此，我重新设置代码格式，然后可以检查“未解决的参考错误”是否消失，但不包括工具栏，fab和R。**

尝试一下，并通知我结果。

package e.lakal.tapfighter

import android.content.ContentValues
import android.content.ContentValues.TAG
import android.os.Bundle
import android.os.CountDownTimer
import android.os.PersistableBundle
import android.util.Log
import android.view.Menu
import android.view.MenuItem
import android.widget.Button
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import com.appg.saltfactory.R
import com.google.android.material.snackbar.Snackbar

class MainActivity : AppCompatActivity() {

    internal lateinit var tapmeButton: Button;
    internal lateinit var GameScore: TextView;
    internal lateinit var Timer: TextView;
    internal var Score = 0
    internal var gameStarted = false

    internal lateinit var countDownTimer: CountDownTimer
    internal val initalCountDown: Long = 60000;
    internal val CountDownInterval: Long = 1000;
    internal val TAG = MainActivity::class.java.simpleName
    internal val timeLeftonTimer: Long = 6000


    companion object {
        private val SCORE_KEY = "SCORE_KEY"
        private val TIME_LEFT_KEY = "TIME_LEFT_KEY"
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.main_activity)
        Log.d(TAG, "On create called. Score is $Score")
        setSupportActionBar(toolbar)

        fab.setOnClickListener { view ->
            Snackbar.make(
                view, "Replace with your own action",
                Snackbar.LENGTH_LONG
            )
                .setAction("Action", null).show()
        }

        tapmeButton = findViewById<Button>(R.id.tapmeButton)
        GameScore = findViewById<TextView>(R.id.GameScore)
        Timer = findViewById<TextView>(R.id.Timer)
        GameScore.text = getString(R.string.YourScore, Score.toString())

        tapmeButton.setOnClickListener { view ->
            incrementScore()
        }
        resetGame()
    }


    private fun resetGame() {

        Score = 0
        GameScore.text = getString(R.string.YourScore, Score.toString())
        val initalTimeLeft = initalCountDown / 1000
        Timer.text = getString(
            R.string.TimeLeft,
            initalTimeLeft.toString()
        )

        countDownTimer = object : CountDownTimer(
            initalCountDown,
            CountDownInterval
        ) {
            override fun onTick(millisUntilFinished: Long) {
                val timeLeft = millisUntilFinished / 1000
                Timer.text = getString(
                    R.string.TimeLeft,
                    timeLeft.toString()
                )
            }

            override fun onFinish() {
                endGame()
            }
        }
        gameStarted = false;
    }


    // Starts giving me problems here
    private fun startGame() {
        countDownTimer.start()
        gameStarted
    }


    override fun onSaveInstanceState(
        outState: Bundle?,
        outPersistentState: PersistableBundle?
    ) {
        super.onSaveInstanceState(outState, outPersistentState)

        outState?.putInt(SCORE_KEY, Score)
        outState?.putLong(TIME_LEFT_KEY, timeLeftonTimer)
        countDownTimer.cancel()

        Log.d(
            ContentValues.TAG, "onSaveInstanceState : Saving score : $Score & Saving Time current $timeLeftonTimer")
    }

    override fun onDestroy() {
        super.onDestroy()
        Log.d(ContentValues.TAG, "onDestroy called.")
    }


    private fun endGame() {
        Toast.makeText(this, getString(R.string.game_over_msg, Score.toString()), Toast.LENGTH_SHORT).show()
        resetGame()

    }

    private fun incrementScore() {
        if (!gameStarted) {
            startGame()
        }
        Score++
        val newScore = getString(R.string.YourScore, Score.toString())
        GameScore.text = newScore
    }


    override fun onCreateOptionsMenu(menu: Menu): Boolean {

        menuInflater.inflate(R.menu.menu_main, menu)
        return true
    }

    override fun onOptionsItemSelected(item: MenuItem): Boolean {

        return when (item.itemId) {
            R.id.action_settings -> true
            else -> super.onOptionsItemSelected(item)
        }
    }
}

答案 1 :(得分：0)

尝试将gradle版本从3.3.1更改为3.2.1 

classpath 'com.android.tools.build:gradle:3.2.1'

答案 2 :(得分：0)

设法找出问题，显然需要将 onSaveInstanceState() 和 onDestory() 移到 onCreate 函数下

更新

dict["Tom"].returnVal()
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