问题
So I tried to make an app that plays Chess. However, for some reason, the first box on my gridview for my chessboard is blank (where the black Rook is) when the game starts. But once I make the first move, it appears with the black rook. Has anyone had an issue with GridView in Android Studio like this before? I will attach pictures below as well as my xml code for the chessboard screen and my code for the GridView.
GridView Before First Move GridView After First Move
<Button
android:id="@+id/resignButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="4dp"
android:text="@string/resign"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/drawButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="1dp"
android:text="@string/draw"
app:layout_constraintBottom_toTopOf="@+id/gridViewBoard"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/gameText"
android:layout_width="197dp"
android:layout_height="36dp"
android:layout_marginStart="18dp"
android:layout_marginTop="12dp"
android:layout_marginEnd="16dp"
android:text="@string/game_text"
android:textAlignment="center"
android:textColor="#000000"
android:textSize="25sp"
app:layout_constraintEnd_toStartOf="@+id/resignButton"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toEndOf="@+id/drawButton"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/aiButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/ai"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent" />
<Button
android:id="@+id/undoButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="4dp"
android:text="@string/undo"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent" />
<GridView
android:id="@+id/gridViewBoard"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginStart="1dp"
android:layout_marginEnd="1dp"
android:layout_marginBottom="49dp"
android:columnWidth="60dp"
android:gravity="center_horizontal"
android:horizontalSpacing="0dp"
android:numColumns="8"
android:padding="0dp"
android:stretchMode="columnWidth"
android:verticalSpacing="0dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/drawButton" />
</androidx.constraintlayout.widget.ConstraintLayout>
And here's the code that creates the Board
package com.example.chess;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.app.AppCompatActivity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.GridView;
import android.widget.TextView;
import android.widget.Toast;
import android.os.Bundle;
import com.example.chess.Model.Chess;
import com.example.chess.Model.Piece;
import com.example.chess.Model.Games;
import com.example.chess.Model.Move;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
//import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.GridView;
import android.widget.TextView;
import android.widget.Toast;
import android.os.Bundle;
import java.util.*;
public class RecordedGamesActivity extends AppCompatActivity implements OnItemClickListener
{
private Chess chess;
private static boolean RUN_ONCE = false;
private SquareAdapter adapter;
private GridView board;
private ArrayList<Move> moves;
private ListIterator<Move> listIterator;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_recorded_games);
if (!RUN_ONCE) {
RUN_ONCE = true;
this.chess = new Chess();
moves = Games.gamesPlayed.get(Games.index);
listIterator = moves.listIterator();
adapter = new SquareAdapter(this, chess.getBoard());
}
final GridView boardView = (GridView)findViewById(R.id.gridViewBoard);
boardView.setAdapter(adapter);
this.board = boardView;
}
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
if (!listIterator.hasNext())
{
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Replay Complete");
builder.setMessage("Quit replay?");
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
startActivity(new Intent(RecordedGamesActivity.this, MainActivity.class));
RUN_ONCE = false;
finish();
}
});
}
Move move = listIterator.next();
chess.move(move.getStart(), move.getEnd());
adapter.notifyDataSetChanged();
board.setAdapter(adapter);
}
@Override
public void onBackPressed() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setTitle("Exit");
builder.setMessage("Quit replay?");
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
startActivity(new Intent(RecordedGamesActivity.this, MainActivity.class));
RUN_ONCE = false;
finish();
}
});
builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
AlertDialog alert = builder.create();
alert.show();
}
}
来源：https://stackoverflow.com/questions/61603530/first-square-on-gridview-is-blank-in-androidstudio