【移动应用开发技术】Android - ToDoList(fragment) 详解

【移动应用开发技术】Android-ToDoList(fragment)详解

ToDoList(fragment)详解版权所有,禁止转载,如有需要,请站内联系.本文地址:

/caroline_wendy/article/details/21246963ToDoList做为Android的经典练习,参考:

/caroline_wendy/article/details/21223995Fragment(碎片)

可以灵活地从一个活动的Activity上添加或删除Fragment,有良好的用户体验;下面是Fragment的具体设计:位置:res->new_item_fragment.xml<?xmlversion="1.0"encoding="utf-8"?><EditTextxmlns:android="/apk/res/android"android:id="@+id/myEditText"android:layout_width="match_parent"android:layout_height="wrap_content"android:hint="@string/addItemHint"android:contentDescription="@string/addItemContentDescription"/>位置:java->package->NewItemFragment.javapackagemzx.spike.todolist.app;importandroid.app.Activity;importandroid.app.Fragment;importandroid.os.Bundle;importandroid.view.KeyEvent;importandroid.view.LayoutInflater;importandroid.view.View;importandroid.view.ViewGroup;importandroid.widget.EditText;/***CreatedbyC.L.Wangon14-3-14.*/publicclassNewItemFragmentextendsFragment{privateOnNewItemAddedListeneronNewItemAddedListener;//监听事件publicinterfaceOnNewItemAddedListener{publicvoidonNewItemAdded(StringnewItem);}@OverridepublicViewonCreateView(LayoutInflaterinflater,ViewGroupcontainer,BundlesavedInstanceState){Viewview=inflater.inflate(R.layout.new_item_fragment,container,false);finalEditTextmyEditText=(EditText)view.findViewById(R.id.myEditText);//监听事件myEditText.setOnKeyListener(newView.OnKeyListener(){@OverridepublicbooleanonKey(Viewview,inti,KeyEventkeyEvent){if(keyEvent.getAction()==KeyEvent.ACTION_DOWN)if((i==KeyEvent.KEYCODE_DPAD_CENTER)||(i==KeyEvent.KEYCODE_ENTER)){StringnewItem=myEditText.getText().toString();onNewItemAddedListener.onNewItemAdded(newItem);myEditText.setText("");returntrue;}returnfalse;}});returnview;}//绑定到ActivitypublicvoidonAttach(Activityactivity){super.onAttach(activity);try{onNewItemAddedListener=(OnNewItemAddedListener)activity;}catch(ClassCastExceptione){thrownewClassCastException(activity.toString()+"mustimplementOnNewItemAddedListener");}}}1.继承Fragment类;2.监听接口(interfaceOnNewItemListener),包含一个监听方法(onNewItemAdded),然后实现一个实例;3.创建视图(onCreateView),需要返回一个视图(View);4.填充一个视图,调用inflater.inflate()函数,绑定fragment的资源文件;5.获得控件的引用,

view.findViewById(),得到myEditText的引用;6.监听事件,监听myEditText的输入内容,传递给接口的内容(newItem);7.使用onAttach()函数,绑定Acitivity之后,获得activity的引用;位置:

java->package->ToDoListFragment.javapackagemzx.spike.todolist.app;importandroid.app.ListFragment;/***CreatedbyC.L.Wangon14-3-14.*/publicclassToDoListFragmentextendsListFragment{}位置:res->layout->activity_to_do_list.xml<LinearLayoutxmlns:android="/apk/res/android"xmlns:tools="/tools"android:orientation="vertical"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="mzx.spike.todolist.app.ToDoListActivity"><fragmentandroid:name="mzx.spike.todolist.app.NewItemFragment"android:id="@+id/NewItemFragment"android:layout_width="match_parent"android:layout_height="wrap_content"android:hint="@string/addItemHint"android:contentDescription="@string/addItemContentDescription"/><fragmentandroid:name="mzx.spike.todolist.app.ToDoListFragment"android:id="@+id/ToDoListFragment"android:layout_width="match_parent"android:layout_height="wrap_content"/></LinearLayout>位置:

java->package->ToDoListActivityt.javapackagemzx.spike.todolist.app;importandroid.app.FragmentManager;importandroid.os.Bundle;importandroid.support.v7.app.ActionBarActivity;importandroid.view.Menu;importandroid.view.MenuItem;importandroid.widget.ArrayAdapter;importjava.util.ArrayList;publicclassToDoListActivityextendsActionBarActivityimplementsNewItemFragment.OnNewItemAddedListener{privateArrayAdapter<String>aa;privateArrayList<String>toDoItems;@OverrideprotectedvoidonCreate(BundlesavedInstanceState){super.onCreate(savedInstanceState);setContentView(R.layout.activity_to_do_list);//获得fragment的引用FragmentManagerfm=getFragmentManager();ToDoListFragmenttoDoListFragment=(ToDoListFragment)fm.findFragmentById(R.id.ToDoListFragment);toDoItems=newArrayList<String>();//三个参数aa=newArrayAdapter<String>(this,android.R.layout.simple_list_item_1,toDoItems);toDoListFragment.setListAdapter(aa);}//重写了接口的方法publicvoidonNewItemAdded(StringnewItem){toDoItems.add(newItem);aa.notifyDataSetChanged();}@OverridepublicbooleanonCreateOptionsMenu(Menumenu){//Inflatethemenu;thisaddsitemstotheactionbarifitispresent.getMenuInflater().inflate(R.menu.to_do_list,menu);returntrue;}@OverridepublicbooleanonOptionsItemSelected(MenuItemitem){//Handleactionbaritemclickshere.Theactionbarwill