Android Studio开发井字棋点击Play Again按钮应用闪退求助

问题根源 #

点击Play Again按钮闪退是**类型转换异常（ClassCastException）**导致的：

• Java代码中导入的是原生android.widget.GridLayout
• XML布局里使用的是AndroidX的androidx.gridlayout.widget.GridLayout
• 在okayPlay方法中强转GridLayout时类型不匹配，直接触发崩溃

修复方法 #

步骤1：修改MainActivity.java的导入语句 #

把原有导入的GridLayout替换为AndroidX版本：

// 删掉原有 import android.widget.GridLayout;
import androidx.gridlayout.widget.GridLayout;

步骤2：可选优化建议 #

将GridLayout、Play Again按钮、获胜提示TextView改为全局变量，仅在onCreate中初始化一次，减少重复查找控件的开销，修正后的完整代码参考：

package com.example.tictac;

import androidx.appcompat.app.AppCompatActivity;
import androidx.gridlayout.widget.GridLayout;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;


public class MainActivity extends AppCompatActivity {
    //0:cross,1:red,2:empty
    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;
    // 全局控件变量
    GridLayout gridLayout;
    Button playAgainButton;
    TextView winnerTextView;

    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.cross);
                activePlayer = 1;
            } else {
                counter.setImageResource(R.drawable.redd);
                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) {
                    //someone win
                    gameActive = false;
                    String winner = "";
                    if (activePlayer == 1) {
                        winner = "Black";
                    } else {
                        winner = "Red";
                    }

                    winnerTextView.setText(winner  + " has won");
                    playAgainButton.setVisibility(View.VISIBLE);
                    winnerTextView.setVisibility(View.VISIBLE);

                }
            }
        }
    }
    public void okayPlay(View view){
        playAgainButton.setVisibility(View.INVISIBLE);
        winnerTextView.setVisibility(View.INVISIBLE);
        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);
        // 初始化全局控件
        gridLayout = findViewById(R.id.gridLayout);
        playAgainButton = findViewById(R.id.playAgainButton);
        winnerTextView = findViewById(R.id.winnerTextView);
    }
}

修改完成后重新编译运行即可解决闪退问题，游戏状态会正常重置。

内容的提问来源于stack exchange，提问作者Rachana Velore