使 Dialog 类识别来自 Android 中 MainActivity 类的变量值

如何解决使 Dialog 类识别来自 Android 中 MainActivity 类的变量值

我正在开发一款应用，当用户点击页面顶部的“笑话”按钮时，该应用会随机显示一个笑话。当用户单击此按钮时，将出现一个对话框，其中将显示笑话的标题、设置和用于显示另一个对话框的妙语按钮，该对话框将显示笑话的妙语。当我创建对话框时，我试图弄清楚如何将标题和消息设置为 MainActivity.java 文件中声明的数组的值。到目前为止，我能够找出在两个对话框之间来回切换并随时退出它们的代码。但是，我被困在如何从 MainActivity java 文件中检索对话框 java 文件中的数组值。我尝试向 MainActivity 文件中的 buttonShowDialog() 和 onOKClick 方法添加代码，但这不会使对话框文件识别数组值。我认为这是一个 OOP 问题，但我被卡住了。任何建议将不胜感激。

主Activity.java

package edu.psu.jjb24.csjokes;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.MenuInflater;
import android.view.MenuItem;

import java.util.Random;

public class MainActivity<currentJoke> extends AppCompatActivity implements DisplaySetupDialog.OKClickListener,DisplayPunchlineDialog.OKClickListener{
    String[] joke_title;
    String[] joke_setup;
    String[] joke_punchline;
    int currentJoke = -1;

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

        // Set the action bar
        Toolbar myToolbar = findViewById(R.id.toolbar);
        setSupportActionBar(myToolbar);

        joke_title = getResources().getStringArray(R.array.JokeTitle);
        joke_setup = getResources().getStringArray(R.array.JokeSetup);
        joke_punchline = getResources().getStringArray(R.array.JokePunchline);
    }


    public int getCurrentJoke(String[] array){
        int random = new Random().nextInt(array.length);
        currentJoke = random;
        return currentJoke;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.activity_main,menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_joke:
                buttonShowDialog();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    public void buttonShowDialog() {
        DisplaySetupDialog setupDialog = new DisplaySetupDialog();
        setupDialog.show(getSupportFragmentManager(),"setupDialog");
    }

    public void onOKClick() {
        DisplayPunchlineDialog punchlineDialog = new DisplayPunchlineDialog();
        punchlineDialog.show(getSupportFragmentManager(),"punchlineDialog");
    }

    public void onOKClick2() {
        buttonShowDialog();
    }
}

DisplaySetupDialog.java

package edu.psu.jjb24.csjokes;

import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Context;
import android.os.Bundle;

import androidx.fragment.app.DialogFragment;

public class DisplaySetupDialog extends DialogFragment{
    public interface OKClickListener {
        public void onOKClick();
    }

    private OKClickListener mListener;
    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState){
        AlertDialog.Builder setup = new AlertDialog.Builder(getActivity());

        setup.setTitle("joke_title").setMessage("joke_setup")
                .setPositiveButton("Punchline",new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog,int id){
                        mListener.onOKClick();
                    }

                })
                .setNegativeButton("Cancel",int id) {

                    }
                });
        return setup.create();
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

        try {
            mListener = (OKClickListener) context;
        }
        catch (ClassCastException e) {
            throw new ClassCastException(context.toString() + "must implement OKClickListener");
        }
    }

}

DiplayPunchlineDialog.java

import android.os.Bundle;

import androidx.fragment.app.DialogFragment;

public class DisplayPunchlineDialog extends DialogFragment {
    public interface OKClickListener {
        public void onOKClick2();
    }

    private DisplayPunchlineDialog.OKClickListener mListener2;

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState){
        AlertDialog.Builder setup = new AlertDialog.Builder(getActivity());

        setup.setTitle("joke_title").setMessage("joke punchline")
                .setPositiveButton("Setup",int id){
                        mListener2.onOKClick2();
                    }

                })
                .setNegativeButton("Done",int id) {

                    }
                });
        return setup.create();
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);

        try {
            mListener2 = (DisplayPunchlineDialog.OKClickListener) context;
        }
        catch (ClassCastException e) {
            throw new ClassCastException(context.toString() + "must implement OKClickListener");
        }
    }

}

解决方法

当您创建 Fragment 的新实例时，您应该将 Fragment 需要的信息（笑话）传递给它。为了让 Fragment 正确处理运行时配置更改，您应该在创建新的 Fragment 实例时使用我们在 Android 中使用的特殊模式：

https://stackoverflow.com/a/56544233/2104665