Android开发之ListView、GridView 详解及示例代码

2019-12-12 05:30:10

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ListView与GridView是Android开发中的常用控件，它们和Adapter配合使用能够实现很多界面效果。下面分别以实例说明ListView、GridView的用法。

1.ListView的Android开发实例

ListView 是android开发中最常用的控件之一，一般构成列表包括三个元素，ListView:用来展示列表的视图、Adapter：数据与视图连接的桥梁、Data:具体的数据包括字符串、图片或者控件。

适配器一般有以下几种类型：

ArrayAdapter：Android中最简单的一种适配器，专门用于列表控件。只显示一行数据。

SimpleAdapter：此适配器有最好的扩充性，可以自定义出各种效果。经常使用静态数据填充列表。

CursorAdapter：通过游标向列表提供数据。

ResourceCursorAdapter：这个适配器扩展了CursorAdapter，知道如何从资源创建视图。

SimpleCursorAdapter：这个适配器扩展了ResourceCursorAdapter，从游标中得列创建 TextView/ImageView视图。下面获取通讯录的示例：

XML/HTML代码

<?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"     android:background="@drawable/bg"          >     <ListView      android:id="@+id/contacts_list"     android:layout_width="fill_parent"     android:layout_height="fill_parent"     >     </ListView>   </LinearLayout>

Java代码

package net.csdn.blog.androidtoast;      import java.util.ArrayList;   import java.util.HashMap;   import java.util.Map;      import android.app.Activity;   import android.database.Cursor;   import android.os.Bundle;   import android.provider.ContactsContract;   import android.view.View;   import android.widget.AdapterView;   import android.widget.ListAdapter;   import android.widget.ListView;   import android.widget.SimpleAdapter;   import android.widget.Toast;      public class MainActivity extends Activity {           ListView   mListView;      ArrayList<Map<String, String>> listData;             static final String NAME = "name";     static final String NUMBER = "number";     /** Called when the activity is first created. */     @Override     public void onCreate(Bundle savedInstanceState) {       super.onCreate(savedInstanceState);       setContentView(R.layout.main);       getContacts();     }        /**     * 获取联系人列表     */     private void getContacts() {       mListView=(ListView) findViewById(R.id.contacts_list);       listData = new ArrayList<Map<String, String>>();       //获取数据库Cursor       Cursor cur=getContentResolver().query(ContactsContract.Contacts.CONTENT_URI, null, null, null, null);       startManagingCursor(cur);       while (cur.moveToNext()) {        Map<String, String> mp = new HashMap<String, String>();        long id = cur.getLong(cur.getColumnIndex("_id"));        Cursor pcur = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,            null, ContactsContract.CommonDataKinds.Phone.CONTACT_ID + "=" + Long.toString(id), null, null);                    // 处理多个号码的情况        String phoneNumbers = "";        while (pcur.moveToNext()) {           String strPhoneNumber = pcur.getString(pcur.getColumnIndex(              ContactsContract.CommonDataKinds.Phone.NUMBER));              phoneNumbers += strPhoneNumber + ":";        }           phoneNumbers += "/n";           pcur.close();                          String name = cur.getString(cur.getColumnIndex("display_name"));           mp.put(NAME, name);           mp.put(NUMBER, phoneNumbers);           listData.add(mp);       }       cur.close();               // 建立一个适配器去查询数据       ListAdapter adapter = new SimpleAdapter(this, listData, android.R.layout.simple_list_item_2,           new String[]{NAME, NUMBER},           new int[] {android.R.id.text1, android.R.id.text2});       mListView.setAdapter(adapter);       //为listView添加事件监听       mListView.setOnItemSelectedListener(new ListView.OnItemSelectedListener(){         @Override         public void onItemSelected(AdapterView<?> parent, View view,             int position, long id) {           Toast.makeText(getApplicationContext(), "当前所在行为："+Long.toString(parent.getSelectedItemId()+1), 1).show();         }            @Override         public void onNothingSelected(AdapterView<?> parent) {           // TODO Auto-generated method stub                    }                });     }   }

2.GridView的Android开发实例

GridView 网格视图，用于显示多行多列。直接上示例：

XML/HTML代码

<?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"     android:background="@drawable/bg"     >     <GridView       android:id="@+id/gridview"       android:layout_width="fill_parent"       android:layout_height="wrap_content"       android:numColumns="3"/>          </LinearLayout>  XML/HTML代码<?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" android:scrollbars="vertical">      <ImageView             android:layout_height="100dip"             android:id="@+id/ItemImage"             android:layout_width="80dip"            android:src="@drawable/png1"            android:layout_gravity="center_horizontal"/>                     <TextView             android:layout_width="wrap_content"             android:layout_height="wrap_content"            android:layout_gravity="center"            android:id="@+id/ItemText" />    </LinearLayout>

Java代码

package net.csdn.blog.androidtoast;      import java.util.ArrayList;   import java.util.HashMap;      import android.app.Activity;   import android.os.Bundle;   import android.view.Gravity;   import android.view.View;   import android.widget.AdapterView;   import android.widget.GridView;   import android.widget.SimpleAdapter;   import android.widget.Toast;      public class MainActivity extends Activity {     /** Called when the activity is first created. */     //定义图片整型数组     private int[] mImages={         R.drawable.png1,         R.drawable.png2,         R.drawable.png3,         R.drawable.png4,         R.drawable.png5,         R.drawable.png6,         R.drawable.png7,         R.drawable.png8,         R.drawable.png9        };     @Override     public void onCreate(Bundle savedInstanceState) {       super.onCreate(savedInstanceState);       setContentView(R.layout.main);              //实例化GridView       GridView mGridView=(GridView) findViewById(R.id.gridview);       // 生成动态数组，并且传入数据       ArrayList<HashMap<String, Object>> lstImageItem = new ArrayList<HashMap<String, Object>>();              for (int i = 0; i < 9; i++) {         HashMap<String, Object> map = new HashMap<String, Object>();         map.put("ItemImage", mImages[i]);// 添加图像资源的ID         map.put("ItemText", "NO." + String.valueOf(i+1));// 按序号做ItemText         lstImageItem.add(map);       }       //构建一个适配器       SimpleAdapter simple = new SimpleAdapter(this, lstImageItem, R.layout.gridviewitem,           new String[] { "ItemImage", "ItemText" }, new int[] {R.id.ItemImage, R.id.ItemText });       mGridView.setAdapter(simple);       //添加选择项监听事件       mGridView.setOnItemClickListener(new GridView.OnItemClickListener(){        @Override         public void onItemClick(AdapterView<?> parent, View view, int position, long id) {           Toast toast=Toast.makeText(getApplicationContext(), "你选择了"+(position+1)+"号图片", 1);           toast.setGravity(Gravity.BOTTOM, 0, 0);           toast.show();         }                });            }   }