android两个所在不同页面的(listView EditView)传递数据 问题？

为什么第一行老显示null?
总是只能查询上一步操作所填入的数据！

EditView id=text_friend 按钮id=publish

listView id=obtain

ListView中：
public class FirendSend extends Activity {

private EditText text_friend;
private SharedPreferences sp;
private SharedPreferences.Editor editor;

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.friend_send);
    Button Button_back=(Button)findViewById(R.id.back);
    sp = getSharedPreferences("data", MODE_PRIVATE);
    editor = sp.edit();
    Button button = (Button) findViewById(R.id.publish);
    text_friend = (EditText) findViewById(R.id.text_friend);

    button.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            String txt = sp.getString("text", null);
            editor.putString("text", txt + ";;;"
                    + text_friend.getText().toString());
            editor.commit();
            Toast.makeText(FirendSend.this, "发表成功", Toast.LENGTH_SHORT).show();
        }
    });

    Button_back.setOnClickListener(new ExitClickListener());
}



 class ExitClickListener implements  OnClickListener{
     public void onClick(View v){
         System.exit(0);

}
}
}

EditView中：

public class Firend extends Activity {
private SharedPreferences sp;
private ImageButton imageButton;
private ArrayList texts;
private ListView obtain;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.send_friend);
    initData();
    obtain = (ListView) findViewById(R.id.obtain);
    imageButton = (ImageButton) findViewById(R.id.submit);
    imageButton.setOnClickListener(new OnClickListener() {
        public void onClick(View v) {
            Toast.makeText(Firend.this, "欢迎进入", Toast.LENGTH_SHORT).show();
            Intent intent = new Intent(Firend.this, FirendSend.class);
            startActivity(intent);
        }
    });
    obtain.setAdapter(new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_1, texts));
}

private void initData() {
    // TODO Auto-generated method stub
    sp = getSharedPreferences("data", MODE_PRIVATE);
    String str = sp.getString("text", null);

    texts = new ArrayList<String>();

    while (str != null && str.length()> 0) {
        int index = str.indexOf(";;;");
        if (index <= 0) 
        {
            return;
        }   
        texts.add(str.substring(0, index));
        str = str.substring(index + 3);

    }

}
}

用Bundle传递，在startActivity的时候，给Intent设置一个Bundle，如下
Bundle bundler = new Bundle();
bundler.putString("TEST", "test");
intent.putExtras(bundler);

第一行总显示null，是因为你初次进入FirendSend的时候在保存数据的时候，根据你上面保存数据的代码：
首先执行String txt = sp.getString("text", null);得到txt的值为null；
然后你执行txt + ";;;"+ text_friend.getText().toString()也就相当于null+";;;"+text_friend.getText().toString()",其结构就是“null;;;xxxx”
之后当你再进行解析的时候，第一行自然就是“null”了。

是不是你绑定数据没更新