问题
plz help me out in this problem i tried many changes that were suggested in android studio basically the problem occurs in playAgain function it crashes but it shold clear the images im the imageviews
main activity
package com.example.xo;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.GridLayout;
import android.widget.ImageView;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
0=o,1=x,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;
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).setDuration(300);
for (int[] winningPosition : winningPositions) {
if (gameState[winningPosition[0]] == gameState[winningPosition[1]] && gameState[winningPosition[1]] == gameState[winningPosition[2]] && gameState[winningPosition[0]] != 2) {
gameActive = false;
String winner = "";
if (activePlayer == 1) {
winner = "O";
} else {
winner = "X";
}
Button playAgainButton = (Button) findViewById(R.id.playAgainButton);
TextView winnerTextView = (TextView) findViewById(R.id.winnerTextView);
winnerTextView.setText(winner + " 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 gridLayout1 = (GridLayout) findViewById(R.id.gridLayout1);
for (int i = 0; i < gridLayout1.getChildCount(); i++) {
ImageView counter = (ImageView) gridLayout1.getChildAt(i);
counter.setImageResource(0);
}
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);
}
}
Activity main
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/ConstraintLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<androidx.gridlayout.widget.GridLayout
android:id="@+id/gridLayout1"
android:layout_width="409dp"
android:layout_height="409dp"
android:layout_marginTop="8dp"
android:background="@drawable/b"
app:columnCount="3"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:rowCount="3">
<ImageView
android:id="@+id/imageView6"
android:layout_width="137dp"
android:layout_height="143dp"
android:contentDescription="@string/todo"
android:onClick="dropIn"
android:tag="5"
app:layout_column="2"
app:layout_row="1" />
<ImageView
android:id="@+id/imageView5"
android:layout_width="127dp"
android:layout_height="150dp"
android:contentDescription="@string/todo"
android:onClick="dropIn"
android:tag="4"
app:layout_column="1"
app:layout_row="1" />
<ImageView
android:id="@+id/imageView4"
android:layout_width="129dp"
android:layout_height="134dp"
android:contentDescription="@string/todo"
android:onClick="dropIn"
android:scaleType="fitXY"
android:tag="3"
app:layout_column="0"
app:layout_row="1" />
<ImageView
android:id="@+id/imageView2"
android:layout_width="117dp"
android:layout_height="127dp"
android:contentDescription="@string/todo"
android:onClick="dropIn"
android:scaleType="fitCenter"
android:tag="1"
app:layout_column="1"
app:layout_row="0" />
<ImageView
android:id="@+id/imageView3"
android:layout_width="132dp"
android:layout_height="129dp"
android:contentDescription="@string/todo"
android:onClick="dropIn"
android:tag="2"
app:layout_column="2"
app:layout_row="0" />
<ImageView
android:id="@+id/imageView7"
android:layout_width="140dp"
android:layout_height="122dp"
android:contentDescription="@string/todo"
android:onClick="dropIn"
android:tag="6"
app:layout_column="0"
app:layout_row="2" />
<ImageView
android:id="@+id/imageView8"
android:layout_width="130dp"
android:layout_height="131dp"
android:contentDescription="@string/todo"
android:onClick="dropIn"
android:tag="7"
app:layout_column="1"
app:layout_row="2" />
<ImageView
android:id="@+id/imageView9"
android:layout_width="137dp"
android:layout_height="125dp"
android:contentDescription="@string/todo"
android:onClick="dropIn"
android:tag="8"
app:layout_column="2"
app:layout_row="2" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="129dp"
android:layout_height="127dp"
android:contentDescription="@string/todo"
android:onClick="dropIn"
android:scaleType="centerInside"
android:tag="0"
app:layout_column="0"
app:layout_row="0" />
</androidx.gridlayout.widget.GridLayout>
<Button
android:id="@+id/playAgainButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="276dp"
android:layout_marginLeft="276dp"
android:layout_marginBottom="56dp"
android:onClick="playAgain"
android:text="@string/play_again"
android:visibility="visible"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent" />
<TextView
android:id="@+id/winnerTextView"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="36dp"
android:layout_marginLeft="36dp"
android:layout_marginBottom="56dp"
android:text="@string/textview"
android:textSize="30sp"
android:visibility="invisible"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
**> > > Logcat
2019-10-18 23:32:30.422 13338-13338/com.example.xo E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.xo, PID: 13338 java.lang.IllegalStateException: Could not execute method for android:onClick at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:390) at android.view.View.performClick(View.java:7125) at android.view.View.performClickInternal(View.java:7102) at android.view.View.access$3500(View.java:801) at android.view.View$PerformClick.run(View.java:27336) at android.os.Handler.handleCallback(Handler.java:883) at android.os.Handler.dispatchMessage(Handler.java:100) at android.os.Looper.loop(Looper.java:214) at android.app.ActivityThread.main(ActivityThread.java:7356) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) Caused by: java.lang.reflect.InvocationTargetException at java.lang.reflect.Method.invoke(Native Method) at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:385) at android.view.View.performClick(View.java:7125) at android.view.View.performClickInternal(View.java:7102) at android.view.View.access$3500(View.java:801) at android.view.View$PerformClick.run(View.java:27336) at android.os.Handler.handleCallback(Handler.java:883) at android.os.Handler.dispatchMessage(Handler.java:100) at android.os.Looper.loop(Looper.java:214) at android.app.ActivityThread.main(ActivityThread.java:7356) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) Caused by: java.lang.ClassCastException: androidx.gridlayout.widget.GridLayout cannot be cast toandroid.widget.GridLayout at com.example.xo.MainActivity.playAgain(MainActivity.java:96) at java.lang.reflect.Method.invoke(Native Method) at androidx.appcompat.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:385) at android.view.View.performClick(View.java:7125) at android.view.View.performClickInternal(View.java:7102) at android.view.View.access$3500(View.java:801) at android.view.View$PerformClick.run(View.java:27336) at android.os.Handler.handleCallback(Handler.java:883) at android.os.Handler.dispatchMessage(Handler.java:100) at android.os.Looper.loop(Looper.java:214) at android.app.ActivityThread.main(ActivityThread.java:7356) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930) 2019-10-18 23:32:30.438 13338-13338/com.example.xo I/Process: Sending signal. PID: 13338 SIG:**
回答1:
GridLayout you are using in xml is different from gridlayout you import in your java class. Both must be same. The error is java.lang.ClassCastException and the reason for error is in your xml you are using androidx gridlayout and in your java class, you are using android gridlayout.
来源：https://stackoverflow.com/questions/58456382/what-should-i-do-to-run-this-play-again-button-app-crashes-when-its-pressedmak