android的adapter控件在哪,Android常用控件之GridView使用BaseAdapter

我们可以为GridView添加自定义的Adapter，首先看下用自定义Adapter的显示效果

在布局文件main.xml文件中定义一个GridView控件

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

tools:context=".MainActivity" >

android:id="@+id/gridView"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:numColumns="4"

android:stretchMode="columnWidth" >

要使用BaseAdapter首先定义一个类继承BaseAdapter，并重写几个方法

package com.example.gridviewadapterdemo;

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AdapterView;

import android.widget.BaseAdapter;

import android.widget.GridView;

import android.widget.ImageView;

import android.widget.AdapterView.OnItemClickListener;

public class MainActivity extends Activity {

private GridView gridView = null;

private int[] imageId = new int[] { R.drawable.img01, R.drawable.img02,

R.drawable.img03, R.drawable.img04, R.drawable.img05,

R.drawable.img06, R.drawable.img07, R.drawable.img08,

R.drawable.img09, R.drawable.img10, R.drawable.img11,

R.drawable.img12, }; // 定义并初始化保存图片id的数组

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

gridView = (GridView) findViewById(R.id.gridView);

GridViewAdapter gridViewAdapter = new GridViewAdapter();

gridView.setAdapter(gridViewAdapter);

// 为GridView设定监听器

gridView.setOnItemClickListener(new gridViewListener());

}

class gridViewListener implements OnItemClickListener {

@Override

public void onItemClick(AdapterView> arg0, View arg1, int arg2,

long arg3) {

// TODO Auto-generated method stub

System.out.println("arg2 = " + arg2); // 打印出点击的位置

}

}

private class GridViewAdapter extends BaseAdapter {

@Override

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

ImageView imageview; // 声明ImageView的对象

if (convertView == null) {

imageview = new ImageView(MainActivity.this); // 实例化ImageView的对象

imageview.setScaleType(ImageView.ScaleType.CENTER_INSIDE); // 设置缩放方式

imageview.setPadding(5, 0, 5, 0); // 设置ImageView的内边距

} else {

imageview = (ImageView) convertView;

}

imageview.setImageResource(imageId[position]); // 为ImageView设置要显示的图片

return imageview; // 返回ImageView

}

/*

* 功能：获得当前选项的ID

*

* @see android.widget.Adapter#getItemId(int)

*/

@Override

public long getItemId(int position) {

//System.out.println("getItemId = " + position);

return position;

}

/*

* 功能：获得当前选项

*

* @see android.widget.Adapter#getItem(int)

*/

@Override

public Object getItem(int position) {

return position;

}

/*

* 获得数量

*

* @see android.widget.Adapter#getCount()

*/

@Override

public int getCount() {

return imageId.length;

}

}

}

样例代码