Android UI 학습 - ListView (android. R. layot. simple list item 1 은 무엇 입 니까)

 Android UI   - ListView 

2010-06-20 18:21:35 

  ：Android  UI      ListView  ListActivity 

 

    ，    ，                      、        。         。http://android.blog.51cto.com/268543/336162 

 



ListActivity



    ListActivity       ListView Activity ，    ListView  ，          ，         。



 



  custom view for screen layout



       ListActivity   ListView  ，         custom view，   onCreate()    setContentView(resources id)。



           ，     Layout  ，   ListView   id "@android:id/list"； Java     android.R.id.list。



         ，      id android:empty TextView， ListView    data   ，    "No data"。



nodata



        View (listview.xml)：





<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

         android:orientation="vertical"

         android:layout_width="fill_parent" 

         android:layout_height="fill_parent">



         <ListView android:id="@id/android:list"

                 android:layout_width="fill_parent"

                 android:layout_height="fill_parent"

                 android:layout_weight="1"

         />



         <TextView android:id="@id/android:empty"

                 android:layout_width="fill_parent"

                 android:layout_height="wrap_content"

                 android:text="No data"

                 android:textColor="#ff0000"

         />

</LinearLayout>



      Layout：





@Override

public void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);

         setContentView(R.layout.listview);



         //    data source

 }



 



Row Layout



       ListItem Layout (R.layout)，        ，      API DOC R.layout http://androidappdocs.appspot.com/reference/android/R.layout.html：

◾android.R.layout.simple_list_item_1     text

◾android.R.layout.simple_list_item_2     title，  text

◾android.R.layout.simple_list_item_single_choice       

◾android.R.layout.simple_list_item_multiple_choice       

◾android.R.layout.simple_list_item_checked    checkbox



          Layout (list_item.xml)：





<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

         android:orientation="horizontal"

         android:layout_width="fill_parent"

         android:layout_height="fill_parent">



         <ImageView android:id="@+id/icon"

                 android:layout_width="48dip"

                 android:layout_height="48dip" />



         <TextView android:id="@+id/text"

                 android:layout_gravity="center_vertical"

                 android:layout_width="0dip"

                 android:layout_weight="1"

                 android:layout_height="wrap_content" />



</LinearLayout>



    ， R.layout.list_item     。    http://androidappdocs.appspot.com/resources/tutorials/views/hello-listview.html。



 



    



        SetListAdapter(ListAdapter adapter)    。    implements ListAdapter          。API     implements ListAdapter Adapter：BaseAdapter，SimpleAdapter ( Map         )，SimpleCursorAdapter (         )  。       extends BaseAdapter      Adapter ，  BaseAdapter    Apdater    。  BaseAdapter            ：



    int     getCount()                       Adapter Items  



    Object getItem(int position)         position Item



    long     getItemId(int position)      position Item List  row id



    View    getView(int position, View convertView, ViewGroup parent)      position     data View



            BaseAdapter    android.widget.Adapter   ，       ListAdapter boolean     isEnabled(int position)       。



                  ：



    1.   ArrayAdapter





public void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);



         //  ArrayAdapter     

        setListAdapter(new ArrayAdapter<String>(this,

                         android.R.layout.simple_list_item_1,

                         mStrings));



         // ListView     ，              Item

         getListView().setTextFilterEnabled(true);

 }



private String[] mStrings = {"A", "Android", "   ", "Google"};



ArrayAdapter ArrayAdapter



 



    2.   SimpleCursorAdapter



      Sample  List3  ，       android.provider.Contacts.Phones   ，    。





protected void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);



         // Get a cursor with all phones

         Cursor c = getContentResolver().query(Phones.CONTENT_URI, null, null, null, null);

         startManagingCursor(c);

         

         // Map Cursor columns to views defined in simple_list_item_2.xml

         ListAdapter adapter = new SimpleCursorAdapter(this,

                         android.R.layout.simple_list_item_2, c, 

                                         new String[] { Phones.NAME, Phones.NUMBER }, 

                                         new int[] { android.R.id.text1, android.R.id.text2 });

         setListAdapter(adapter);

 }



 



    3. ListItem     





public void onCreate(Bundle savedInstanceState) {

         super.onCreate(savedInstanceState);



         //  ArrayAdapter     

        setListAdapter(new ArrayAdapter<String>(this,

                         android.R.layout.simple_list_item_single_choice,

                         mStrings));



         final ListView listView = getListView();

         listView.setItemsCanFocus(false);

         listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE); //      

}



private String[] mStrings = {"A", "Android", "   ", "Google"};



singliechoice singliechoice



 



    4. ListItem     



       3    android.R.layout.simple_list_item_multiple_choice      ListView.CHOICE_MODE_MULTIPLE。



 



            Sample，      List     ：



List1 -   ArrayAdapter setTextFilterEnabled(true)



List2 -   SimpleCursorAdapter     People.NAME



List3 -   SimpleCursorAdapter     Phones，    Item



List4 -      Adapter     ItemView



List5 -   separator ListView，     Adapter，  boolean isEnabled(int position)



List6 -      Adapter     ItemView，       



List7 -   SimpleCursorAdapter    



List8 -     setEmptyView  



List9 -   OnScrollListener



List10 - ListItem     



List11 - ListItem     



List12 -       ListItem



List13 -         ，during scrolls or flings   



List14 -        List Adapter



 



  List14，      ：



To work efficiently the adapter implemented here uses two techniques:



 * - It reuses the convertView passed to getView() to avoid inflating View when it is not necessary



 * - It uses the ViewHolder pattern to avoid calling findViewById() when it is not necessary



 



      ViewHolder    ：



 * The ViewHolder pattern consists in storing a data structure in the tag of the view returned by



 * getView(). This data structures contains references to the views we want to bind data to, thus



 * avoiding calls to findViewById() every time getView() is invoked.



 



                 ，     Adapter，            notifyDataSetChanged()   ListView，  List12   ，  ArrayAdapter        ，        ，           BaseAdapter，ArrayAdapter       notifyDataSetChanged()。         《  Android     》     ！



  



ListView     



          ListItem     ：protected void onListItemClick(ListView l, View v, int position, long id) ，       ，               。



     “  Android”   ，        http://android.blog.51cto.com/268543/336162