Java Android SDK public void获取一个错误

我有一个问题，按照教程制作一个应用程序。但是现在我通过添加一个respond得到了一个错误 为了一个按钮。它在public void sendMessage中给出了一个错误，但我看不出有什么错

 package com.example.myfirstapp;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.content.Intent;




/** Called when the user clicks the Send button */

public void sendMessage(View view){

Intent intent = new Intent(this, DisplayMessageActivity.class);
}


public class MainActivity extends ActionBarActivity {

    @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;
    }

    @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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

那些台词

/** Called when the user clicks the Send button */

public void sendMessage(View view){ 
  Intent intent = new Intent(this, DisplayMessageActivity.class);
}

下课后去上课

public class MainActivity extends ActionBarActivity {

---

你的职能不在活动范围之内

移动

像这样的内部活动：

public class MainActivity extends ActionBarActivity {

    //other code i.e. onCreate etc

    public void sendMessage(View view){
        Intent intent = new Intent(this, DisplayMessageActivity.class);
    }

}

---

请发布日志的相关部分。你甚至在上课之前就定义了一个方法？？？？奇怪。

public class MainActivity extends ActionBarActivity {

    //other code i.e. onCreate etc

    public void sendMessage(View view){
        Intent intent = new Intent(this, DisplayMessageActivity.class);
    }

}