eclipse Android项目在手机上面运行的时候点击button按钮自动退出，请大神多多指点！！

[lxslxslxs123]

前台页面

后台代码
package com.example.demo;

import android.support.v7.app.ActionBarActivity;
import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

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);
}

public class ButtonTest extends Activity{

public void onClick_Event(View view) {

TextView textview = (TextView)findViewById(R.id.textView1);
textview.setText("你点击了Button");

}

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

Button button=(Button)findViewById(R.id.button1);
MyButton listener=new MyButton();
button.setOnClickListener(listener);
}

class MyButton implements OnClickListener
{
public void onClick(View v)
{
System.out.println("123");
}
}
}
}