有个部分不懂了，想请大家多多帮助

package irdc.ex05_01;

import android.app.Activity;
import android.os.Bundle;
import android.text.util.Linkify;
import android.view.KeyEvent;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;


public class EX05_01 extends Activity
{
  private TextView mTextView01;
  private EditText mEditText01;
 
    /** Called when the activity is first created. */
    @Override
  public void onCreate(Bundle savedInstanceState)
    {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
   
    mTextView01 = (TextView)findViewById(R.id.myTextView1);
    mEditText01 = (EditText)findViewById(R.id.myEditText1);
   
    mEditText01.setOnKeyListener(new EditText.OnKeyListener()
    {   
      @Override
      public boolean onKey(View arg0, int arg1, KeyEvent arg2)
      {
        // TODO Auto-generated method stub
        mTextView01.setText(mEditText01.getText());
        /*判断输入的类型是何种，并与系统连接*/
        Linkify.addLinks(mTextView01, Linkify.WEB_URLS|Linkify.PHONE_NUMBERS|Linkify.EMAIL_ADDRESSES);
        return false;
      }
    });  
    }
}

以上的代码中为什么在onKey函数中结束部分要return false呢？谢谢大家的帮助。