Java Can'；t获取textview以在android上显示用户输出

我正在尝试制作一个基本的应用程序，以获取用户名（输入）并显示用户名（输出）。然而，我似乎无法让这段代码显示我想要的输出。我刚来到安卓。如何在用户输出中显示字符串

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谢谢。

为什么要使用两种活动？主反转器，保留任何一个活动。它会解决你的问题。为什么你在活动中有活动？？“我刚来到安卓。”

public class Main extends Activity {

    Button reverse;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView displayed = (TextView)findViewById(R.id.displayName);
        EditText nametext = (EditText)findViewById(R.id.name);
        String namestring = nametext.getText().toString();

        reverse=(Button)findViewById(R.id.reverse);//assuming you have button with id reverse

            reverse.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub

                    String reverse = new StringBuffer(namestring).reverse().toString();
                    String dr = reverse;
                    displayed.setText(dr);

                }
            });


    }

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

}

    package com.example.basicapp;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class Main extends Activity {

    Button reverse;

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

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

    public class Reverser extends android.app.Activity {
        TextView displayed = (TextView)findViewById(R.id.displayName);
        EditText nametext = (EditText)findViewById(R.id.name);
        String namestring = nametext.getText().toString();


        public void onClickListener() {

            reverse.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub

                    String reverse = new StringBuffer(namestring).reverse().toString();
                    String dr = reverse;
                    displayed.setText(dr);

                }
            });


        }

    }

}

public class Main extends Activity {

    Button reverse;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView displayed = (TextView)findViewById(R.id.displayName);
        EditText nametext = (EditText)findViewById(R.id.name);
        String namestring = nametext.getText().toString();

        reverse=(Button)findViewById(R.id.reverse);//assuming you have button with id reverse

            reverse.setOnClickListener(new View.OnClickListener() {

                @Override
                public void onClick(View v) {
                    // TODO Auto-generated method stub

                    String reverse = new StringBuffer(namestring).reverse().toString();
                    String dr = reverse;
                    displayed.setText(dr);

                }
            });


    }

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

}