Android version to-do-list, practice the use of fragment

Source: Internet
Author: User

Directly post code, too lazy to say these old knowledge points

First, the main activity: include a title, an entry to add a list to think, in fact, below is our listfragment used to display the list of items, and can be deleted

Todolistactivity:

 package com.example.learn;import android.app.activity;import android.os.bundle;import  android.view.view;import android.widget.edittext;/** * created by gongxufan  on 2014/10/30. */public class ToDoListActivity extends Activity  implements todolistfragment.todolistinterface{    private edittext todo;      @Override     public void oncreate (bundle  Savedinstancestate)     {        super.oncreate ( Savedinstancestate);         setcontentview (R.layout.todolist);         todo =  (EditText) Findviewbyid (R.id.additem);     }    public void additem (VIEW V) {         addtodolistitem (Todo.gettExt (). toString ());    }     @Override     public  void addtodolistitem (String itemname)     {         TodoListFragment ft =   (todolistfragment) Getfragmentmanager (). Findfragmentbyid (r.id.todolist);         ft.addtodolist (ItemName);     }}

Corresponding layout file: R.layout.todolist

<?xml version= "1.0"  encoding= "Utf-8"? ><linearlayout xmlns:android= "http// Schemas.android.com/apk/res/android "               android:orientation= "Vertical"                android:layout_width= "Match_parent"                android:layout_height= "Match_parent"                android:gravity= "Center_horizontal" >    < Textview            android:layout_width= "Match_ Parent "            android:layout_height=" Wrap_ Content "            android:text=" To-Do-List "             android:id= "@+id/textview"              android:gravity= "Center"/>    <linearlayout             xmlns:android= "http://schemas.android.com/apk/res/ Android "            android:orientation=" Horizontal "            android:layout_width=" match _parent "            android:layout_height=" Wrap_ Content "            android:gravity=" center >     <EditText             Android:layout_width= "Wrap_content"              android:layout_height= "Wrap_content"             android:layout_weight= "4"              android:layout_gravity= "Fill_horizontal"              android:id= "@+id/addItem"              />         <button android:layout_width= "Wrap_content"  android:onclick= "AddItem"                  android:layout_height= "Wrap_content"  android:text= "Add"  android:layout_weight= "1"/>       </ Linearlayout>    <fragment android:layout_width= "Match_parent"                android:name= " Com.example.learn.TodoListFragment "&NBSP;&NBSP;&NBSP;&NBSP;&Nbsp;         android:layout_height= "Wrap_content"                android:id= "@+id/todoList" ></ Fragment></linearlayout>

As mentioned on the three components, the mid-term nested linear layout, fagment is also a linear layout nested results

Next is the Todolistfragment code, which is mainly a listfragment, with three parts: EditText and two buttons, because we use the custom item layout, we must specify an ID of "@+id/android: List "layout,

The adapter then implements the specific layout of the item item. Put down 2 layout files first:

<?xml version= "1.0"  encoding= "Utf-8"? ><linearlayout xmlns:android= "http// Schemas.android.com/apk/res/android "               android:orientation= "Vertical"                android:layout_width= "Match_parent"                android:layout_height= "Match_parent" >    <listview             android:id= "@+id/android:list"              android:layout_width= "Fill_parent"              android:layout_height= "Wrap_content"              /></LinearLayout>

This is the main layout file for Listfragment, which is called in Oncreateview, and the custom view is added to the ListView as an item in the adapter.

Here is a little explanation, why listfragment main layout file must have an ID list of the ListView, in fact, this is the listfragment to help us realize the function of the ListView.

In the adapter View getView (final int position, view Convertview, ViewGroup parent) The parent in this method is actually an instance of the ListView in the above layout file, looking at the debug result:

<?xml version= "1.0"  encoding= "Utf-8"?><linearlayout         xmlns:android= "Http://schemas.android.com/apk/res/android"          android:orientation= "Horizontal"         android:layout_ Width= "Match_parent"         android:layout_height= "Wrap_content" >     <EditText             Android:layout_width= "Wrap_content"              android:layout_height= "Wrap_content"              Android:id= "@+id/todolistcontent"  android:layout_weight= "8"/>    <button             style= "Android:attr/buttonstylesmall"        &Nbsp;     android:layout_width= "Wrap_content"              android:layout_height= "Wrap_content"              android:text= "Edit"              android:id= "@+id/edititem"  android:layout_weight= "1"/>    < Button            style= "? android:attr/ Buttonstylesmall "            android:layout_width= "Wrap_content"             android:layout_height= " Wrap_content "            android:text=" Delete "             android:id= "@+id/deleteItem"  android: layout_weight= "1"/></linearlayoUt> 

The above is the layout of each item, very simple

Next, paste the Listfragment code:

package com.example.learn;import android.app.activity;import android.app.fragment;import  android.app.listfragment;import android.os.bundle;import android.view.layoutinflater;import  android.view.view;import android.view.viewgroup;import android.widget.*;import  java.util.arraylist;import java.util.hashmap;import java.util.list;import java.util.map;/**  * Created by gongxufan on 2014/10/30. */public class  todolistfragment extends listfragment{    private todolistinterface  callback;    private list<string> data = new arraylist< String> ();     private baseadapter baseadapter;    public  interface ToDoListInterface{        public void  Addtodolistitem (String itemname);    }    private class ViewHolder{         EditText todoItem;        Button edit;         Button delete;    }     Public todolistinterface getcallback ()     {         return callback;    }     @Override      public void onattach (activity activity)     {         super.onattach (activity);         callback  =  (todolistinterface) activity;    }     @Override      public void ondetach ()     {         super.ondetach ();        callback = null;    }     public void addtodolist (String itemname) {         data.add (ItemName);         Baseadapter.notifydatasetchanged ();    }     @Override      public void oncreate (bundle savedinstancestate)     {         super.oncreate (savedinstancestate);         baseadapter = new baseadapter ()          {             @Override              public int getcount ()              {                return data.size ();             }              @Override              public object getitem (int position)              {                 return data.get (position);             }              @Override              public long getitemid (int position)              {                 return position;             }             @Override              public view getview (final int  Position, view convertview, viewgroup parent)              {                 LayoutInflater mInflater =  (Layoutinflater)   TodoListFragment.this.getActivity ()                      .getsystemservice (TodoListFragment.this.getActivity (). Layout_inflater_service);                 viewholder viewholder = null; &nBsp;              if (convertView ==  null) {                     viewholder = new viewholder ();                     convertView =  Minflater.inflate (R.layout.ltodolist_item,parent,false);                     viewHolder.todoItem =  (EditText) Convertview.findviewbyid (r.id.todolistcontent);                     viewHolder.edit =  (Button) Convertview.findviewbyid (R.id.edititem);                     viewHolder.delete =  (Button) Convertview.findviewbyid (R.id.deleteitem);                      Convertview.settag (Viewholder);                 }else{                     viewHolder =  (Viewholder) Convertview.gettag ();                 }                 viewholder.todoitem.settext (String) GetItem ( Position));                 ViewHolder.delete.setOnClickListener (New view.onclicklistener ()                  {                      @Override                      public void onclick (VIEW&NBSP;V)                      {                         data.remove (GetItem (position));                          baseadapter.notifydatasetchanged ();                     }                  });                 return convertView;            }         };        setlistadapter ( Baseadapter);    }     @Override     public  View oncreateview (layoutinflater inflater, viewgroup container, bundle  Savedinstancestate)     {        return  Inflater.inflate (R.layout.todolist_fragment, container, false);    }      @Override     public void onlistitemclick (listview l, view  v, int position, long id)     {         super.onlistitemclick (l,  v, position, id);     }} 

The code is also simple, just a baseadapter for a custom layout, then a response to delete, add event handling, change the adapter data to re-ui layout

Ok a simple rough to-do-list finished, just to practice under fragment use, I novice, forget forgive me.

Emulator Run Result:

Android version to-do-list, practice the use of fragment

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