<android程式碼>傳送畫面問題 ~麻煩各位好心大大!!

在MainActivity.java
public class MainActivity extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btSearch=(Button)this.findViewById(R.id.bt1);
final EditText txtBookName=(EditText)this.findViewById(R.id.txt1);
btSearch.setOnClickListener(new View.OnClickListener() {

      public void onClick(View view) {
        Intent intent=new Intent(MainActivity.this,DisplayBooks.class);
        intent.putExtra("bookName",txtBookName.getText().toString());
        startActivity(intent);
      }
    });
}
}
在DisplayBooks.java
public class DisplayBooks extends ListActivity {

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.book);
// TextView txtBook=(TextView)this.findViewById(R.id.txtTitle);
// txtBook.setText(this.getIntent().getExtras().getString("bookName"));
//
// TextView txtBook1=(TextView)this.findViewById(R.id.txtSubTitle);
// txtBook1.setText(this.getIntent().getExtras().getString("bookName"));

ArrayList<HashMap<String,String>>list=new ArrayList<HashMap<String,String>>();
HashMap<String,String> map=new HashMap<String,String>();
map.put("title", "Book1");
map.put("subTitle", "BookDetail1");
list.add(map);

map=new HashMap<String,String>();
map.put("title", "Book2");
map.put("subTitle", "BookDetail2");
list.add(map);

SimpleAdapter adapter=new SimpleAdapter(this,list,R.layout.book,
    new String[]{"title","subTitle"},new int[]{R.id.txtTitle,R.id.txtSubTitle});
this.setListAdapter(adapter);

}
}

從MainActivity.java傳送到DisplayBooks.java 我是用Intent 其中bookname是互相傳送的參數
但是在DisplayBooks.java 的註解那部分程式碼跟下面程式碼好像有衝突

Logcat顯示的錯誤訊息是
10-13 12:59:56.153: E/AndroidRuntime(562): FATAL EXCEPTION: main
10-13 12:59:56.153: E/AndroidRuntime(562): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.eason/com.eason.DisplayBooks}: java.lang.RuntimeException: Your content must have a ListView whose id attribute is 'android.R.id.list'

不曉得程式碼應該怎麼改?????

麻煩各位大大!!感恩

應該是你的 layout 內容有問題。
沒有定義應該要有的 ID