(android) 在GridView中实现单选或多选功能

最近在做项目的过程中，要用到GridView，同时还得使用单选或多选功能，在网上搜过很多资源贴，但都不是我想要的效果，于是就自行设计了一种方案。什么都不说，先上个效果图^_^: Demo源代码下载：http://download.csdn.net/down/3435752/anndaming



首先需要构建一个ImageAdapter类，此类继承了BaseAdapter类，用于做GridView中资源的适配器，代码如下：

package com.demo;

import java.util.Vector;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.LayerDrawable;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;

public class ImageAdapter extends BaseAdapter{
private Context mContext; // 定义Context
private Vector<Integer> mImageIds = new Vector<Integer>(); // 定义一个向量作为图片源
private Vector<Boolean> mImage_bs = new Vector<Boolean>(); // 定义一个向量作为选中与否容器

private int lastPosition = -1; //记录上一次选中的图片位置，-1表示未选中任何图片
private boolean multiChoose; //表示当前适配器是否允许多选

public ImageAdapter(Context c, boolean isMulti){
mContext = c;
multiChoose = isMulti;

// 装入资源
mImageIds.add(R.drawable.item1);
mImageIds.add(R.drawable.item2);
mImageIds.add(R.drawable.item3);
mImageIds.add(R.drawable.item4);
mImageIds.add(R.drawable.item5);
for(int i=0; i<5; i++)
mImage_bs.add(false);
}

@Override
public int getCount() {
// TODO Auto-generated method stub
return mImageIds.size();
}

@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}

@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
ImageView imageView;
if (convertView == null)
{
imageView = new ImageView(mContext); // 给ImageView设置资源
imageView.setLayoutParams(new GridView.LayoutParams(50, 50)); // 设置布局图片
imageView.setScaleType(ImageView.ScaleType.FIT_CENTER); // 设置显示比例类型
}
else
{
imageView = (ImageView) convertView;
}
imageView.setImageDrawable(makeBmp(mImageIds.elementAt(position),
mImage_bs.elementAt(position)));

return imageView;
}

private LayerDrawable makeBmp(int id, boolean isChosen){
Bitmap mainBmp = ((BitmapDrawable)mContext.getResources().getDrawable(id)).getBitmap();

// 根据isChosen来选取对勾的图片
Bitmap seletedBmp;
if(isChosen == true)
seletedBmp = BitmapFactory.decodeResource(mContext.getResources(),
R.drawable.btncheck_yes);
else
seletedBmp = BitmapFactory.decodeResource(mContext.getResources(),
R.drawable.btncheck_no);

// 产生叠加图
Drawable[] array = new Drawable[2];
array[0] = new BitmapDrawable(mainBmp);
array[1] = new BitmapDrawable(seletedBmp);
LayerDrawable la = new LayerDrawable(array);
la.setLayerInset(0, 0, 0, 0, 0);
la.setLayerInset(1, 0, -5, 60, 45 );

return la; //返回叠加后的图
}

// 修改选中的状态
public void changeState(int position){
// 多选时
if(multiChoose == true){
mImage_bs.setElementAt(!mImage_bs.elementAt(position), position); //直接取反即可
}
// 单选时
else{
if(lastPosition != -1)
mImage_bs.setElementAt(false, lastPosition); //取消上一次的选中状态
mImage_bs.setElementAt(!mImage_bs.elementAt(position), position); //直接取反即可
lastPosition = position; //记录本次选中的位置
}
notifyDataSetChanged(); //通知适配器进行更新
}
}

接下是配置main.xml文件：

<?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"
>
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal">
<TextView
android:text="单选功能"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="40dp"
android:gravity="center"/>
<GridView android:id="@+id/gridview_radio"
android:layout_width="250dp"
android:layout_height="150dp"
android:numColumns="4"
android:padding="10dp"
android:horizontalSpacing="4dp"
android:verticalSpacing="4dp"
android:gravity="center"/>
</LinearLayout>

<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:gravity="center_horizontal">
<TextView
android:text="多选功能"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:textSize="40dp"
android:gravity="center"/>
<GridView android:id="@+id/gridview_check"
android:layout_width="250dp"
android:layout_height="150dp"
android:numColumns="4"
android:padding="10dp"
android:horizontalSpacing="4dp"
android:verticalSpacing="4dp"
android:gravity="center"/>
</LinearLayout>
</LinearLayout>

最后写一个Activity作测试：

package com.demo;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.GridView;
import android.widget.AdapterView.OnItemClickListener;

public class DemoActivity extends Activity {
GridView gridView_radio; //单选宫格
GridView gridView_check; //多选宫格

ImageAdapter ia_radio; //存储图片源的适配器(单选)
ImageAdapter ia_check; //存储图片源的适配器(多选)

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

// 单选的宫格
gridView_radio = (GridView) findViewById(R.id.gridview_radio);
ia_radio = new ImageAdapter(this, false);
gridView_radio.setAdapter(ia_radio);
// 设置点击监听
gridView_radio.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3) {
// TODO Auto-generated method stub
ia_radio.changeState(position);
}
});

// 多选的宫格
gridView_check = (GridView) findViewById(R.id.gridview_check);
ia_check = new ImageAdapter(this, true);
gridView_check.setAdapter(ia_check);
// 设置点击监听
gridView_check.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1,
int position, long arg3) {
// TODO Auto-generated method stub
ia_check.changeState(position);
}
});
}
}