android 页面跳转，数据回传

package com.example.firstpg.firstpg;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.Window;
import android.widget.Toast;
import android.content.Intent;

public class FirstlayoutActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
     //requestWindowFeature(Window.FEATURE_ACTION_BAR);
        setContentView(R.layout.firstlayout);
    }

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

        //noinspection SimplifiableIfStatement
          switch (id)
          {
              case R.id.add_item:
                  Toast.makeText(this,"大海啊大海",Toast.LENGTH_SHORT).show();
                  break;
              case R.id.edit_item:
                  Intent intent=new Intent(FirstlayoutActivity.this,SecondlayoutActivity.class);
                  startActivity(intent);
                  break;
              case  R.id.del_item:
                  Intent intent2=new Intent(FirstlayoutActivity.this,SecondlayoutActivity.class);
                  intent2.putExtra("data1", "你好1");
                  startActivityForResult(intent2,1);
                   break;
                  default:
                      finish();
          }

        return super.onOptionsItemSelected(item);
    }
    protected void onActivityResult(int requestCode,int resultCode,Intent data)
    {
     switch (requestCode) {
         case 1:
             if (resultCode == RESULT_OK) {
                 String retrundata = data.getStringExtra("data2");
                 Log.d("data2", retrundata);
             }
             break;
     }
    }
}

package com.example.firstpg.firstpg;

import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;


public class SecondlayoutActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.secondlayout);
        Intent intent=getIntent();
        String data=intent.getStringExtra("data1");
         Log.d("data1", data);
         Button button2=(Button)findViewById(R.id.button2);
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intert=new Intent();
                intert.putExtra("data2","你好2");
                setResult(RESULT_OK,intert);
                finish();
            }
        });
    }

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

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}
　　　　

<RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin" tools:context=".FirstlayoutActivity">

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="195dp" />

</RelativeLayout>

<RelativeLayout 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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="com.example.firstpg.firstpg.SecondlayoutActivity">



    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button2"
        android:layout_centerVertical="true"
        android:layout_centerHorizontal="true" />

</RelativeLayout>

menu

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools" tools:context=".FirstlayoutActivity">
    <item android:id="@+id/add_item" android:title="添加"  />
    <item android:id="@+id/edit_item" android:title="修改"  />
    <item android:id="@+id/del_item" android:title="回传数据测试"  />
    <item android:id="@+id/return_item" android:title="退出"  />
</menu>