每当我点击 playAgain 按钮时，应用程序就会崩溃

Question

Java 我是 Android 开发的新手，我正在开发简单的井字游戏。当我点击按钮时，应用程序崩溃了。这是一种十字和圆圈游戏，连续三个十字或圆圈匹配的人获胜。游戏结束后，Textview 和 Button 出现。目的是在点击再次播放按钮后游戏应该重新开始。这是 Java.

中的代码

package com.example.tictactoe;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.GridLayout;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {


    int[] gameState = {2, 2, 2, 2, 2, 2, 2, 2, 2};

    int[][] winningPositions = {{0, 1, 2}, {3, 4, 5}, {6, 7, 8}, {0, 3, 6}, {1, 4, 7}, {2, 5, 8}, {0, 4, 8}, {2, 4, 6}};

    int activePlayer = 0;

    boolean gameActive = true;

    public void dropIn(View view) {

        ImageView counter = (ImageView) view;

        int tappedCounter = Integer.parseInt(counter.getTag().toString());

        if (gameState[tappedCounter] == 2 && gameActive) {

            gameState[tappedCounter] = activePlayer;

            counter.setTranslationY(-1500);

            if (activePlayer == 0) {

                counter.setImageResource(R.drawable.o);
                activePlayer = 1;

            } else {
                counter.setImageResource(R.drawable.x);
                activePlayer = 0;
            }

            counter.animate().translationYBy(1500).rotation(3600).setDuration(300);

            for (int[] winningPosition : winningPositions) {

                if (gameState[winningPosition[0]] == gameState[winningPosition[1]] && gameState[winningPosition[1]] == gameState[winningPosition[2]] && gameState[winningPosition[0]] != 2) {

                    // Somone has won!

                    gameActive = false;

                    String winner = "";

                    if (activePlayer == 1) {

                        winner = "Circle";

                    } else {

                        winner = "Cross";

                    }

                    Button playAgainButton = (Button) findViewById(R.id.playAgainButton);

                    TextView winnerTextView = (TextView) findViewById(R.id.winnerTextView);

                    winnerTextView.setText(winner + " has won!");

                    playAgainButton.setVisibility(View.VISIBLE);

                    winnerTextView.setVisibility(View.VISIBLE);

                }

            }
        }
    }

    public void playAgain(View view) {

        Button playAgainButton = (Button) findViewById(R.id.playAgainButton);

        TextView winnerTextView = (TextView) findViewById(R.id.winnerTextView);

        playAgainButton.setVisibility(View.INVISIBLE);

        winnerTextView.setVisibility(View.INVISIBLE);

        GridLayout gridLayout = (GridLayout) findViewById(R.id.gridLayout);

        for(int i=0; i<gridLayout.getChildCount(); i++) {

            ImageView counter = (ImageView) gridLayout.getChildAt(i);

            counter.setImageDrawable(null);

        }

        for (int i=0; i<gameState.length; i++) {

            gameState[i] = 2;

        }

        activePlayer = 0;

        gameActive = true;

    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
}

Logcat 当按钮被点击时。

2022-01-26 00:03:53.763 11101-11101/com.example.tictactoe E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.tictactoe, PID: 11101
    java.lang.IllegalStateException: Could not execute method for android:onClick
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:446)
        at android.view.View.performClick(View.java:7448)
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119)
        at android.view.View.performClickInternal(View.java:7425)
        at android.view.View.access00(View.java:810)
        at android.view.View$PerformClick.run(View.java:28305)
        at android.os.Handler.handleCallback(Handler.java:938)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:223)
        at android.app.ActivityThread.main(ActivityThread.java:7656)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Method.invoke(Native Method)
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:441)
        at android.view.View.performClick(View.java:7448) 
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119) 
        at android.view.View.performClickInternal(View.java:7425) 
        at android.view.View.access00(View.java:810) 
        at android.view.View$PerformClick.run(View.java:28305) 
        at android.os.Handler.handleCallback(Handler.java:938) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:223) 
        at android.app.ActivityThread.main(ActivityThread.java:7656) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947) 
     Caused by: java.lang.ClassCastException: androidx.gridlayout.widget.GridLayout cannot be cast to android.widget.GridLayout
        at com.example.tictactoe.MainActivity.playAgain(MainActivity.java:95)
        at java.lang.reflect.Method.invoke(Native Method) 
        at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:441) 
        at android.view.View.performClick(View.java:7448) 
        at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119) 
        at android.view.View.performClickInternal(View.java:7425) 
        at android.view.View.access00(View.java:810) 
        at android.view.View$PerformClick.run(View.java:28305) 
        at android.os.Handler.handleCallback(Handler.java:938) 
        at android.os.Handler.dispatchMessage(Handler.java:99) 
        at android.os.Looper.loop(Looper.java:223) 
        at android.app.ActivityThread.main(ActivityThread.java:7656) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

这里是 XML 按钮。

<Button
        android:id="@+id/playAgainButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="162dp"
        android:layout_marginTop="5dp"
        android:layout_marginEnd="162dp"
        android:layout_marginBottom="21dp"
        android:onClick="playAgain"
        android:text="Play Again"
        android:visibility="invisible"
        app:layout_constraintBottom_toTopOf="@+id/gridLayout"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/winnerTextView" />

我不确定如何解决这个问题，点击“再玩一次”按钮后游戏应该会重新启动。所以希望有人能提供帮助。谢谢

Answer 1

原因：java.lang.ClassCastException：androidx.gridlayout.widget.GridLayout 无法转换为 android.widget.GridLayout 在 com.example.tictactoe.MainActivity.playAgain(MainActivity.java:95)

修复此 class 转换异常。

编辑：

GridLayout gridLayout = (GridLayout) findViewById(R.id.gridLayout);
                                         ^
                                     This thing

我不使用这个框架。

如果你已经写了 findViewById ...也许它以某种方式返回了错误的类型...就像那个东西 returns andoidX.bladibla.gridLayout 而不是 android.bladibla.gridlayout 所以检查一下。

还有

import androidx.appcompat.app.AppCompatActivity;

这是您示例的顶部。它里面有一个 X...所以也许看看它是怎么回事。

无论如何...您的问题...class演员表。这就是你必须研究的。

每当我点击 playAgain 按钮时，应用程序就会崩溃

Whenever i click on playAgain button the app get crashed

java

crash

android

button