安卓學習UI組件-listView

時間 2019-12-04

原文原文鏈接

1.ListView組件介紹java

佈局文件arrays.xmlandroid

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

        <item>C#編程詞典</item>
        <item>JAVA編程詞典</item>
        <item>VB編程詞典</item>
        <item>VC編程詞典</item>
        <item>ASP編程詞典</item>
        <item>Delphi編程詞典</item>
        <item>ASP.NET編程詞典</item>
        <item>C#編程詞典</item>
        <item>JAVA編程詞典</item>
        <item>VB編程詞典</item>
        <item>VC編程詞典</item>
        <item>ASP編程詞典</item>
        <item>Delphi編程詞典</item>
        <item>ASP.NET編程詞典</item>
    </array>
</resources>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.administrator.myapplication.MainActivity">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/listView"
        android:cacheColorHint="#00000000"
        android:dividerHeight="10dp"
        android:divider="#70DB93"

        android:fadingEdge="vertical"
        android:scrollbars="horizontal|vertical"

        android:fastScrollEnabled="true"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true"
        android:listSelector="#ffaadd"

      android:entries="@array/name"

        />
</RelativeLayout>

 編程

public class MainActivity extends Activity {

    private ListView listView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listView=(ListView)findViewById(R.id.listView);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                TextView tv=(TextView)view;
                Toast.makeText(MainActivity.this,tv.getText(),Toast.LENGTH_SHORT).show();
            }
        });
    }
}

2.基本的XML配置app

(1)Xml Attributrs:ide

(2)事件處理佈局

 優化

 this

 spa

3.ListActivity.net

public class MainActivity2 extends ListActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ArrayAdapter arrayAdapter=ArrayAdapter.createFromResource(
                this, R.array.name, android.R.layout.simple_list_item_1);
        setListAdapter(arrayAdapter);
    }


    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);

        Toast.makeText(this, ((TextView) v).getText(), Toast.LENGTH_SHORT).show();
    }
}

4.單選和多選模式

多選模式：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.administrator.myapplication.MainActivity3">

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/listView"

        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true" />
</RelativeLayout>

public class MainActivity3 extends Activity {

    private ListView listView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main3);
        listView=(ListView)findViewById(R.id.listView);
        String[] arr=getResources().getStringArray(R.array.name);
        //單選模式
       ArrayAdapter<String> aa=new ArrayAdapter<String>(this,
       android.R.layout.simple_list_item_single_choice,arr);
   listView.setChoiceMode(ListView.CHOICE_MODE_SINGLE);

        //多選模式
   /*    ArrayAdapter<String> aa=new ArrayAdapter<String>(this,
   android.R.layout.simple_list_item_multiple_choice,arr);
        listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);*/
        listView.setAdapter(aa);
    }
}

5.ListView實現圖文列表-優化

自定義適配器

（1）

list_item_4.xml

<?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"
    android:gravity="center_vertical"
    android:padding="16dp">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/imageView_icon"
        android:src="@drawable/ic_launcher"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Text"
        android:layout_marginLeft="10dp"
        android:id="@+id/textView_title" />
</LinearLayout>

--------------------------

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.administrator.myapplication.MainActivity4">

    <ListView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/listView3"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true" />
</RelativeLayout>

---------------------------

/* SimpleAdapter的使用*/
public class MainActivity4 extends Activity {

    private ListView listView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main4);
        listView=(ListView)findViewById(R.id.listView3);
//準備數據 每個HashMap是一條記錄
        HashMap<String,Object> title1=new HashMap<>();
        title1.put("title","title-1");
        title1.put("icon",android.R.drawable.alert_dark_frame);
        HashMap<String,Object> title2=new HashMap<>();
        title2.put("title","title-2");
        title2.put("icon",android.R.drawable.alert_light_frame);
        HashMap<String,Object> title3=new HashMap<>();
        title3.put("title","title-3");
        title2.put("icon",android.R.drawable.arrow_down_float);

           List<Map<String,Object>> list=new ArrayList<>();
          list.add(title1);
          list.add(title2);
          list.add(title3);


          //把數據填充到Adapter
         SimpleAdapter sa=new SimpleAdapter(this,list,R.layout.list_item_4,
         new String[]{"title","icon"},new int[]{R.id.textView_title,R.id.imageView_icon});

        listView.setAdapter(sa);


    }

-------------------------------------------------------------------------

(2)使用自定義適配器填充，並進行優化

 三個文件。一個MainActivity,兩個佈局文件list_item_5.xml,activity_main5.xml

<?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"
    android:gravity="center_vertical"
    android:padding="16dp">

    <ImageView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/imageView_icon"
        android:src="@drawable/ic_launcher"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Text"
        android:layout_marginLeft="10dp"
        android:id="@+id/textView_title" />
</LinearLayout>

--------------------------------

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.administrator.myapplication.MainActivity5"
   >

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/listView4"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true" />
</RelativeLayout>

------------------------

/*使用自定義適配器填充
*
* 優化：
* 1.使ListView的快高固定，避免內容變化致使ListView從新渲染
* 2.使用ConvertView減小對象的建立
* 3.使用ViewHolder減小對象的查找
**/
public class MainActivity5 extends Activity {
    private ListView listView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main5);
        listView=(ListView)findViewById(R.id.listView4);

        listView.setAdapter(new MyAdapter(this));

    }

    static class MyAdapter extends BaseAdapter
    {
        //填充圖片和標題
        private String[] titles={"title_1","title-2","title_3","title_4","title_5",
                "title_6","title-7","title_8","title_9","title_10",
                "title_11","title-12","title_13","title_14","title_15"
        };
        private int[] icons={R.drawable.pic0,R.drawable.pic14,R.drawable.pic2,
        R.drawable.pic4,R.drawable.pic7,
              R.drawable.pic0,R.drawable.pic14,R.drawable.pic2,R.drawable.pic4,R.drawable.pic7,
              R.drawable.pic0,R.drawable.pic14,R.drawable.pic2,R.drawable.pic4,R.drawable.pic7
        };

private Context context;
        public MyAdapter(Context context)
        {
this.context=context;
        }

        @Override
        public int getCount() {
            return titles.length;
        }

        @Override
        public Object getItem(int position) {
            return titles[position];
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {

            ViewHolder vh;
//用convertView進行優化
            if(convertView==null)
            {
                LayoutInflater inflater=LayoutInflater.from(context);
                //實例化一個佈局文件
              convertView=inflater.inflate(R.layout.list_item_5, null);
                vh=new ViewHolder();
                vh.iv_icon=(ImageView)convertView.findViewById(R.id.imageView_icon);
                vh.tv_title=(TextView)convertView.findViewById(R.id.textView_title);
                convertView.setTag(vh);

            }
            else
            {
                vh= (ViewHolder) convertView.getTag();
            }


            /*System.out.println("convertView"+convertView);
            System.out.println(position +"--"+convertView);*/

           /* TextView tv=(TextView)convertView.findViewById(R.id.textView_title);
            ImageView iv=(ImageView)convertView.findViewById(R.id.imageView_icon);
*/
            vh.tv_title.setText(titles[position]);
            vh.iv_icon.setImageResource(icons[position]);

            return convertView;
        }
//用於保存第一次查找的組件，避免下次重複查找
        //ViewHolder優化
        static class ViewHolder
        {
            ImageView iv_icon;
            TextView  tv_title;


        }
    }

}

6.ListView刷新分頁

public void onScrollStateChanged(AbsListView view, int scrollState) {
 //三個狀態
}

五個文件：News.java,MainActivity6.java,activity_main6.xml,list_item_6.xml,loading.xml

list_item_6.xml

<?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="wrap_content"
    android:padding="16dp">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="title"
        android:layout_marginLeft="10dp"
        android:id="@+id/textView_title" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="content"
        android:layout_marginLeft="10dp"
        android:id="@+id/textView_content" />
</LinearLayout>

activity_main6.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.administrator.myapplication.MainActivity6">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/listView5"
        android:layout_alignParentTop="true"
        android:layout_alignParentStart="true" />
</RelativeLayout>

loading.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:gravity="center">

    <ProgressBar
        style="?android:attr/progressBarStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/progressBar" />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:text="正在玩命加載中"
        android:id="@+id/textView" />
</LinearLayout>

News.java

public class News {
    String title;
    String content;

}

MainActivity6.java

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

import java.util.Vector;


/*listView的分頁*/
public class MainActivity6 extends Activity implements AbsListView.OnScrollListener{

    private ListView listView;
  private Vector<News> news=new Vector<>();
    private MyAdapter myAdapter;
    private static final int DATA_UPDATE=0x1;//數據更新完成後的標記 十六進制
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main6);
        listView= (ListView) findViewById(R.id.listView5);
        listView.setOnScrollListener(this);
        View footerView=getLayoutInflater().inflate(R.layout.loading,null);
        listView.addFooterView(footerView);
   initData();
        myAdapter=new MyAdapter();
        listView.setAdapter(myAdapter);

    }
 private int index=1;

/*初始化數據*/
    private void initData()
    {

        for(int i=0;i<10;i++)
        {
     News n= new News();
        n.title="title--"+index;
    n.content="content--"+index;
    index++;
    news.add(n);
        }
    }

 private int visibleLastIndex;//用來可顯示的最後一條數據的索引

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState) {
     //三個狀態
        if(myAdapter.getCount()==visibleLastIndex&&scrollState== 
        AbsListView.OnScrollListener.SCROLL_STATE_IDLE)
        {
            new LoadDataThread().start();
        }
    }

    @Override
    public void onScroll
    (AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {

        visibleLastIndex=firstVisibleItem+visibleItemCount-1;
    }

   //線程之間進行通信的機制
    private Handler handler=new Handler() {
//定義一個內部類 實現方法 處理消息
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
   switch (msg.what)
   {
       case DATA_UPDATE:
           myAdapter.notifyDataSetChanged();
           break;
   }
        }
    };

    //子線程 模擬加載數據的線程
    class LoadDataThread extends  Thread
    {
        public void run()
        {
            //初始化數據
            initData();
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
          //  myAdapter.notifyDataSetChanged(); 出錯 子線程不能直接訪問UI組件
           //經過handler給主線程發送一個消息標記
            handler.sendEmptyMessage(DATA_UPDATE);
        }
    }

  //自定義適配器填充數據
     class MyAdapter extends BaseAdapter
    {

        @Override
        public int getCount() {
            return news.size();
        }

        @Override
        public Object getItem(int position) {
            return news.get(position);
        }

        @Override
        public long getItemId(int position) {
            return position;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            ViewHolder vh;
             if(convertView==null)
             {
                 convertView=getLayoutInflater().inflate(R.layout.list_item_6,null);
                 vh=new ViewHolder();

                 vh.tv_title= (TextView) convertView.findViewById(R.id.textView_title);
                 vh.tv_content= (TextView) convertView.findViewById(R.id.textView_content);
                 convertView.setTag(vh);
             }
            else
             {
                  vh= (ViewHolder) convertView.getTag();

             }
            News n=news.get(position);
            vh.tv_title.setText(n.title);
            vh.tv_content.setText(n.content);

            return convertView;
        }


    }
    static class ViewHolder
    {
        TextView tv_title;
        TextView tv_content;
    }
}

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