如何定义从另一个类调用 MainActivity 的方法?

我想在我创建的另一个类的 MainActivity 中定义一个方法.我在弄清楚这一点时遇到了问题.这甚至可能吗?我在网上找不到关于在另一个类中定义方法的任何信息.

I want to define a method that I have in MainActivity in another class that I created. I am having issues figuring this out. Is this even possible? I am not finding anything online about defining a method in another class.

我已经包含了我的代码和我想如何做的例子.

I have included my code and the example of how I want to do it.

我的主活动代码

package com.example.flashcards;

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    DatabseHelper DB = new DatabseHelper(this);

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

        changeText();
        changeText2();
    }

    private void changeText() {
        final String[] revertText = {"H2O", "What elements does water consist of?"};

        final TextView textChange = (TextView) findViewById(R.id.flashcard1);
        Button change = (Button) findViewById(R.id.answer1);

        change.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int random = (int) (Math.random() * revertText.length);
                textChange.setText(revertText[random]);
            }
        });
    }

我的 TextC 代码(其他类)

My TextC code(other class)

package com.example.flashcards;

import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class TextC extends MainActivity {
    private void changeText2() {
        final String[] revertText = {"2,200° F", "How hot does lava get?"};

        final TextView textChange = (TextView) findViewById(R.id.flashcard2);
        Button change = (Button) findViewById(R.id.answer2);

        change.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int random = (int) (Math.random() * revertText.length);
                textChange.setText(revertText[random]);
            }
        });
    }
}

我在 MainActivity 中定义的方法有效，但我似乎无法从我的其他类中得到它.我正在尝试做的可能吗?我想要在我的 TextC 类中定义 changeText2() 方法，但在我的 MainActivity 中声明，因为 MainActivity 有 onCreate() 方法.

My method defined in the MainActivity works, but I cannot seem to get it to work from my other class. Is what I am trying to do possible? I want changeText2() method defined in my TextC class, but declared in my MainActivity since the MainActivity has the onCreate() method.