Android Studio无法解析类中的方法

Question

I am trying to make a basic connect 3 app as part of a course challenge. The problem I am having is that I am unable to access the methods inside the class Players in order to set which buttons have been pressed by which players: Cannot resolve method 'noughtsPlayer' .

I created an instance of Players on the onCreate method and declared it at the top of the script. That instance itself is recognised but for some reason the contained methods, noughtsPlayer and crossesPlayer are not.

MainActivity.java

package com.example.richardcurteis.connect3;

import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TableLayout;
import android.widget.TableRow;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    public boolean noughtsTurn;
    ArrayList board;
    String players;

    public void receiveClick(View view) {
        String buttonPressed = (String) view.getTag();
        board.remove(buttonPressed);

        if (view instanceof Button) {
            Button B = (Button) view;
            B.setText(noughtsTurn ? players.noughtsPlayer() : players.crossesPlayer());
        }

    }

    class Players {
        public String noughtsPlayer() { return "O"; }
        public String crossesPlayer() { return "X"; }
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                        .setAction("Action", null).show();
            }
        });
        boolean noughtsTurn = true;
        board = new ArrayList();
        for (int x = 0; x < getBoardSize(); x++) {
            String y = String.valueOf(x);
            board.add(y);
        }
        Players players = new Players();

    }

    public int getBoardSize() {
        int buttonCount = 0;
        TableLayout tableLayout = (TableLayout) findViewById(R.id.tableLayout);

        for (int rowIndex = 0; rowIndex < tableLayout.getChildCount(); rowIndex++) {
            View tableLayoutChild = tableLayout.getChildAt(rowIndex);
            if (tableLayoutChild instanceof TableRow) {
                for (int i = 0; i < ((ViewGroup) tableLayoutChild).getChildCount(); i++) {
                    View view = ((ViewGroup) tableLayoutChild).getChildAt(i);
                    if (view instanceof Button) {
                        buttonCount++;
                    }
                }
            }
        }
        return buttonCount;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

Answer 1

You have global variable String players and local variable Players players . This is problem. And class String doesn't have those methods. To solve this problem change String players; to Players players; and Players players = new Players(); to players = new Players();