GridView和ImageSwitcher的功能和用法

main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

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

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    tools:context=".MainActivity" 

    android:orientation="vertical"

    android:gravity="center_horizontal">

    <!-- 定义一个GridView组件 -->

    <GridView android:id="@+id/grid"

        android:layout_width="fill_parent"

        android:layout_height="wrap_content"

        android:horizontalSpacing="1pt"

        android:verticalSpacing="2pt"

        android:numColumns="4"

        android:gravity="center"></GridView>

    <!-- 定义一个ImageSwitcher组件 -->

    <ImageSwitcher android:id="@+id/switcher"

        android:layout_width="120dp"

        android:layout_height="120dp"

        android:layout_gravity="center"

        android:layout_marginTop="20dp"></ImageSwitcher>

</LinearLayout>

Main.java

package com.example.imageswitchertest;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import android.os.Bundle;

import android.app.Activity;

import android.app.AlertDialog;

import android.app.AlertDialog.Builder;

import android.app.Dialog;

import android.util.Log;

import android.view.Menu;

import android.view.View;

import android.view.animation.AnimationUtils;

import android.widget.AbsListView.LayoutParams;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.AdapterView.OnItemSelectedListener;

import android.widget.GridView;

import android.widget.ImageSwitcher;

import android.widget.ImageView;

import android.widget.SimpleAdapter;

import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity {

//制定图片数组

int[] imageIds=new int[]{

R.drawable.aermeiliyan,R.drawable.asenna,R.drawable.gebenhagen,

R.drawable.hengda,R.drawable.kaierteren,R.drawable.liwonuo,R.drawable.mancheng,

R.drawable.manlian

};

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

//创建一个List集合

List<Map<String,Object>> listItems=new ArrayList<Map<String,Object>>();

for(int i=0;i<imageIds.length;i++){

Map<String,Object> oneListItem=new HashMap<String,Object>();

oneListItem.put("image", imageIds[i]);

listItems.add(oneListItem);

}

//获取显示图片的ImageSwitcher

final ImageSwitcher switcher=(ImageSwitcher) super.findViewById(R.id.switcher);

//设置图片更换时候的效果,设置渐隐渐现

switcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));

switcher.setOutAnimation(this, android.R.anim.fade_out);

switcher.setFactory(new ViewFactory(){

public View makeView() {

ImageView imageView=new ImageView(MainActivity.this);

imageView.setBackgroundColor(0xff0000);

//ImageView.ScaleType把图片暗比例扩大/缩小到View的宽度，居中显示

imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);

imageView.setLayoutParams(new ImageSwitcher.LayoutParams(120,120));

return imageView;

}

});

String[] from=new String[]{"image"};

int[] to=new int[]{R.id.imageView};

//创建一个SimpleAdapter

SimpleAdapter simpleAdapter=new SimpleAdapter(

this, 

listItems, 

//使用/res/layout/cell.xml文件作为界面布局

R.layout.cell, 

from, 

to);

GridView grid=(GridView) super.findViewById(R.id.grid);

//为grid设置Adapter

grid.setAdapter(simpleAdapter);

final Builder builder=new AlertDialog.Builder(this);

//添加列表项被选中的监听器

grid.setOnItemSelectedListener(new OnItemSelectedListener(){

public void onItemSelected(AdapterView<?> parent, View view,

int position, long id) {

//显示当前选中的图片

switcher.setImageResource(imageIds[position]);

}

public void onNothingSelected(AdapterView<?> parent) {}

});

//添加列表项被单机的监听器

grid.setOnItemClickListener(new OnItemClickListener() {

@Override

public void onItemClick(AdapterView<?> parent, View view, int position,

long id) {

//显示被单机的图片

switcher.setImageResource(imageIds[position]);

}

});

    }

}

cell.xml

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical" >

    <ImageView android:id="@+id/imageView"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_gravity="center_horizontal"

        android:padding="5dp"/>

</LinearLayout>