GridView 是 AdapterView 的派生類， AdapterView 是 ViewGroup 的派生類， ViewGroup 是 View 的派生類。
什麼是 GridView ？官方的說法是：
A view that shows items in two-dimensional scrolling grid. The items in the grid come from the ListAdapter associated with this view
這句話包含以下幾個意思：
+ GridView 是一個二維可滾動的網格視圖
+ GridView 中的數據是有與之關聯的 ListAdapter 提供的
下面就一個具體的例子來說明 GridView 的用法。
1. 創建一個項目，修改 main.xml 使之如下：
<? xml version = "1.0" encoding = "utf-8" ?>
< GridView xmlns:android = "http://schemas.android.com/apk/res/android"
android:id = "@+id/gridview"
android:layout_width = "fill_parent"
android:layout_height = "fill_parent"
android:background = "#333"
android:columnWidth = "90px"
android:numColumns = "auto_fit"
android:horizontalSpacing = "6px"
android:verticalSpacing = "6px"
android:stretchMode = "columnWidth"
android:gravity = "center" >
<!--
android:columnWidth Set the width of columns in the grid.
android:numColumns Set the number of columns in the grid.
android:stretchMode Control how items are stretched to fill their space.
-->
</ GridView >
2. 將相關的圖片拖入 res/drawable-mdpi 文件夾中：
以上各圖對應的文件名分別爲：
.aa.png, al.png, ar.png. au.png, cf.png, cn
.png, dm
.png, eu
.png, fa
.png, gr
.png, hk
.png, in
.png, ma
.png, pk
.png, ru
.png, sk
.png, uk
.png, us
.png,
3. 自定義 Adapter ，使之如下：
package com.pat.gui;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
public class ImageAdapter extends BaseAdapter
{
private Context ctx;
private int[] images =
{
R.drawable.aa, // Austria
R.drawable.al, // Algeria
R.drawable.ar, // Argentina
R.drawable.au, // Austrilia
R.drawable.cf, // Swizterland
R.drawable.cn, // China
R.drawable.dm, // Denmark
R.drawable.eu, // European Union
R.drawable.fa, // France
R.drawable.gr, // Greece
R.drawable.hk, // Hong Kong
R.drawable.in, // India
R.drawable.ma, // Macau
R.drawable.pk, // Pakistan
R.drawable.ru, // Russia
R.drawable.sk, // South Korea
R.drawable.uk, // United Kingdom
R.drawable.us // United States
};
public ImageAdapter(Context ctx)
{
this.ctx = ctx;
}
//@Override
public int getCount()
{
return images.length;
}
//@Override
public Object getItem(int position)
{
return images[position];
}
//@Override
public long getItemId(int position)
{
return images[position];
}
//@Override
public View getView(int position, View convertView, ViewGroup parent)
{
ImageView view = (ImageView)convertView;
if(view == null)
{
view = new ImageView(ctx);
}
view.setLayoutParams(new GridView.LayoutParams(90, 90));
view.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
view.setPadding(1, 1, 1, 1);
view.setImageResource(images[position]);
return view;
}
}
4. 修改 Activity 所對應的代碼，使之如下：
package com.pat.gui;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class ControlGridView extends Activity
implements
OnItemClickListener
{
private GridView gridview;
private ImageAdapter adapter;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
gridview = (GridView)findViewById(R.id.gridview);
adapter = new ImageAdapter(this);
gridview.setAdapter(adapter);
gridview.setOnItemClickListener(this);
}
//@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
Toast.makeText(this, "" + position, Toast.LENGTH_SHORT).show();
}
}
輸出結果：
點擊中國，得到：
5. 如果想實現下面這樣的效果：
則在上面的基礎上，要做以下變動：
a. 修改 strings.xml 使之如下：
<? xml version = "1.0" encoding = "utf-8" ?>
< resources >
< string name = "hello" > Hello World, ControlGridView! </ string >
< string name = "app_name" > AndroidGUITwenty </ string >
< string name = "aa" > Austria </ string >
< string name = "al" > Algeria </ string >
< string name = "ar" > Argentina </ string >
< string name = "au" > Austrilia </ string >
< string name = "cf" > Switzerland </ string >
< string name = "cn" > China </ string >
< string name = "dm" > Denmark </ string >
< string name = "eu" > European Union </ string >
< string name = "fa" > France </ string >
< string name = "gr" > Greece </ string >
< string name = "hk" > Hong Kong </ string >
< string name = "in" > India </ string >
< string name = "ma" > Macau </ string >
< string name = "pk" > Pakistan </ string >
< string name = "ru" > Russia </ string >
< string name = "sk" > South Korea </ string >
< string name = "uk" > United Kingdom </ string >
< string name = "us" > United States </ string >
</ resources >
b. 在 res/layout 文件夾下，增加一個 xml 文件： itemview.xml
<? 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 = "wrap_content" >
< ImageView
android:id = "@+id/imageview"
android:layout_width = "90px"
android:layout_height = "90px"
/>
< TextView
android:id = "@+id/textview"
android:layout_width = "90px"
android:layout_height = "40px"
android:textSize = "14px"
android:gravity = "center_horizontal"
android:text = ""
/>
</ LinearLayout >
c. 修改自定義的 Adapter 代碼，使之如下：
package com.pat.gui;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
public class ImageAdapter extends BaseAdapter
{
private Context ctx;
private int[] images =
{
R.drawable.aa, // Austria
R.drawable.al, // Algeria
R.drawable.ar, // Argentina
R.drawable.au, // Austrilia
R.drawable.cf, // Swizterland
R.drawable.cn, // China
R.drawable.dm, // Denmark
R.drawable.eu, // European Union
R.drawable.fa, // France
R.drawable.gr, // Greece
R.drawable.hk, // Hong Kong
R.drawable.in, // India
R.drawable.ma, // Macau
R.drawable.pk, // Pakistan
R.drawable.ru, // Russia
R.drawable.sk, // South Korea
R.drawable.uk, // United Kingdom
R.drawable.us // United States
};
private int[] names =
{
R.string.aa,
R.string.al,
R.string.ar,
R.string.au,
R.string.cf,
R.string.cn,
R.string.dm,
R.string.eu,
R.string.fa,
R.string.gr,
R.string.hk,
R.string.in,
R.string.ma,
R.string.pk,
R.string.ru,
R.string.sk,
R.string.uk,
R.string.us
};
public ImageAdapter(Context ctx)
{
this.ctx = ctx;
}
//@Override
public int getCount()
{
return images.length;
}
//@Override
public Object getItem(int position)
{
return images[position];
}
//@Override
public long getItemId(int position)
{
return images[position];
}
//@Override
public View getView(int position, View convertView, ViewGroup parent)
{
LayoutInflater inflater = LayoutInflater.from(ctx);
View view = convertView;
if(view == null)
{
view = inflater.inflate(R.layout.itemview, null);
}
ImageView iv = (ImageView) view.findViewById(R.id.imageview);
TextView tv= (TextView) view.findViewById(R.id.textview);
iv.setImageResource(images[position]);
tv.setText(names[position]);
return view;
}
}
d. Activity 所對應的代碼如下：
package com.pat.gui;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class ControlGridView extends Activity
implements
OnItemClickListener
{
private GridView gridview;
private ImageAdapter adapter;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
gridview = (GridView)findViewById(R.id.gridview);
adapter = new ImageAdapter(this);
gridview.setAdapter(adapter);
gridview.setOnItemClickListener(this);
}
//@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
Toast.makeText(this, "" + position, Toast.LENGTH_SHORT).show();
}
}
運行結果如下：
