跪求大神帮我看看，代码显示没错，就是不能运行

Question

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <LinearLayout
       
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
         >

        <EditText
            android:id="@+id/editext1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="2"
            android:text="EditText" />

        <Button
            android:id="@+id/button1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Button" />
    </LinearLayout>

    <TextView
        
        android:id="@+id/textview1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="TextView" />

</LinearLayout>

package com.example.sy1;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

public class MainActivity extends Activity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        final EditText edittext=(EditText)findViewById(R.id.editext1);

        Button button=(Button)findViewById(R.id.button1);

        final EditText textview=(EditText)findViewById(R.id.textview1);

        button.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View arg0) {

// TODO Auto-generated method stub

textview.setText(""+edittext.getText().toString());

}

});

        

    }

   

    

    @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;

    }

    

}