Android學習之——GridView，androidgridview

Android學習之——GridView，androidgridview
背景知識

    GridView在Android開發中和ListView一樣經常被使用。如我們經常使用的快圖瀏覽，裡面就有將圖片的布局改為網格（即GridView）的選項。還有約X神器——陌陌的搜尋界也是用了GridView。

                      

    

定義

   GridView is a ViewGroup that displays items in a two-dimensional, scrollable grid. The grid items are automatically inserted to the layout using a ListAdapter

   網格視圖是一個二維的可滾動的網格中展示網格項的視圖集合。網格項使用ListAdapter自動插入到布局中。

 

  

Demo

 1.使用SimpleAdapter適配

MainActivity

 1 package com.johntsai.gridviewdemo; 2  3 import java.util.ArrayList; 4 import java.util.HashMap; 5  6 import android.app.Activity; 7 import android.content.Intent; 8 import android.os.Bundle; 9 import android.view.View;10 import android.widget.AdapterView;11 import android.widget.AdapterView.OnItemClickListener;12 import android.widget.GridView;13 import android.widget.SimpleAdapter;14 import android.widget.Toast;15 16 public class MainActivity extends Activity {17     private int ids[]={18         R.drawable.aaa,19         R.drawable.bbb,20         R.drawable.ccc,21         R.drawable.ddd,22         R.drawable.eee,23         R.drawable.fff,24         R.drawable.ggg,25         R.drawable.hhh,26         R.drawable.aaa27     };28     private GridView gridView;29     @Override30     protected void onCreate(Bundle savedInstanceState) {31         super.onCreate(savedInstanceState);32         setContentView(R.layout.activity_main);33         34         gridView = (GridView)findViewById(R.id.gridview);35     36         ArrayList<HashMap<String, Object>> images = new ArrayList<HashMap<String,Object>>();37         for(int i=0;i<ids.length;i++){38             HashMap<String, Object>map = new HashMap<String, Object>();39             map.put("Image", ids[i]);40             map.put("Id", "Android"+i+"號");41             images.add(map);42         }43     44         SimpleAdapter adapter = new SimpleAdapter(this,45                 images, R.layout.gridview_item, 46                 new String[]{"Image","Id"}, new int[]{R.id.imageItem,R.id.idItem});47         gridView.setAdapter(adapter);48         49         gridView.setOnItemClickListener(new OnItemClickListener() {50 51             @Override52             public void onItemClick(AdapterView<?> parent, View view,53                     int position, long id) {54                  Toast.makeText(getApplicationContext(), 55                          "你點擊了" + position+"號", Toast.LENGTH_LONG).show();56 57             }58         });59     }60 }

 

 

 主介面布局檔案

<?xml version="1.0" encoding="utf-8"?><GridView xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/gridview"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:columnWidth="90dp"    android:numColumns="auto_fit"    android:stretchMode="columnWidth"    android:gravity="center"/><!--    android:columnWidth="90dp" 列寬設定為90dp  android:numColumns="auto_fit"列數設定為自動  android:stretchMode="columnWidth" 縮放與列的寬度同步  -->

GridView項布局檔案

 1 <?xml version="1.0" encoding="utf-8"?> 2 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 3     android:layout_width="match_parent" 4     android:layout_height="match_parent"  5     android:paddingBottom="4dip"> 6      7     <ImageView  8         android:id="@+id/imageItem" 9         android:layout_height="70dp"10         android:layout_width="70dp"11         android:layout_centerHorizontal="true"12         />13     <TextView 14         android:id="@+id/idItem"15         android:layout_height="wrap_content"16         android:layout_width="70dp"17         android:layout_centerHorizontal="true"18         android:layout_below="@id/imageItem"19         />20 </RelativeLayout>

運行效果：

          

     2.使用繼承自BaseAdapter的ImageAdapter適配

   

 1 package com.johntsai.gridviewdemo; 2  3 import android.content.Context; 4 import android.view.View; 5 import android.view.ViewGroup; 6 import android.widget.BaseAdapter; 7 import android.widget.GridView; 8 import android.widget.ImageView; 9 10 public class ImageAdapter extends BaseAdapter {11     public Integer [] ImagesIds = {12         R.drawable.aaa,13         R.drawable.bbb,14         R.drawable.ccc,15         R.drawable.ddd,16         R.drawable.eee,17         R.drawable.fff,18         R.drawable.ggg,19         R.drawable.hhh20     };21     private Context context;22     //構造方法23     public ImageAdapter(Context c) {24           context = c;25     }26     @Override27     public int getCount() {28         return ImagesIds.length;29     }30 31     @Override32     public Object getItem(int position) {33         return null;34     }35 36     @Override37     public long getItemId(int position) {38         return 0;39     }40 41     @Override42     public View getView(int position, View convertView, ViewGroup parent) {43         ImageView imageView;   44         if (convertView == null) {45                   imageView = new ImageView(context);46                   imageView.setLayoutParams(new GridView.LayoutParams(100, 100));47                   imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);48                   imageView.setPadding(0, 0, 0, 0);49                   } else {50                       imageView = (ImageView) convertView;51                   }52 53                   imageView.setImageResource(ImagesIds[position]);54                   return imageView;55     }56 57 }

 

 

MainActivity

 1 public class MainActivity extends Activity { 2     private GridView gridView; 3     @Override 4     protected void onCreate(Bundle savedInstanceState) { 5         super.onCreate(savedInstanceState); 6         setContentView(R.layout.activity_main); 7          8         gridView = (GridView)findViewById(R.id.gridview); 9         gridView.setAdapter(new ImageAdapter(getApplicationContext()));10         11         gridView.setOnItemClickListener(new OnItemClickListener() {12 13             @Override14             public void onItemClick(AdapterView<?> parent, View view,15                     int position, long id) {16                  Toast.makeText(getApplicationContext(), 17                          "你點擊了" + position+"號", Toast.LENGTH_LONG).show();18             19             }20         });21     }22 }