Android的图片浏览源码解读


		Android手机操作系统的应用方式灵活，简单，深受广大编程爱好者的喜爱。尤其是它的开源代码，使得我们能够方便的得到自己想要的功能需求。今天我们就为大家带来了有关Android图片浏览的相关方法。 
本文来自：安卓航班网www.apkway.com 
原文链接处： 
http://www.apkway.com/forum.php?mod=viewthread&tid=697&extra= 
首先是Android图片浏览中layout xml: 
java代码： 
Java代码  
[font=宋体]< ?xml version="1.0" encoding="utf-8"?>  
    < RelativeLayout xmlns:android="Android.com/apk/res/Android">http://schemas.Android.com/apk/res/Android" Android:layout_width="fill_parent"  
    Android:layout_height="fill_parent">  
    < ImageSwitcher  
    Android:id="@+id/switcher"  
    Android:layout_width="fill_parent"  
    Android:layout_height="fill_parent"  
    Android:layout_alignParentTop="true"  
    Android:layout_alignParentLeft="true" />  
    < Gallery  
    Android:id="@+id/gallery"  
    Android:background="#55000000"  
    Android:layout_width="fill_parent"  
    Android:layout_height="60dp"  
    Android:layout_alignParentBottom="true"  
    Android:layout_alignParentLeft="true"  
    Android:gravity="center_vertical"  
    Android:spacing="16dp" />  
    < /RelativeLayout> [/font]  
layout里面用到了前面所说的两个控件，ImageSwitcher用啦显示全图，Gallery用来显示缩略图。着重看看ImageSwitcher,在ImageSwitcher1中需要实现ViewSwitcher.ViewFactory这个接口，这个接口里有个方法makeView，这样就产生了用来显示图片的view. ImageSwitcher调用过程是这样的，首先要有一个Factory为它提供一个View，然后ImageSwitcher就可以初始化各种资源了。注意在使用一个ImageSwitcher之前，一定要调用setFactory方法，要不setImageResource这个方法会报空指针异常。 
       下面是Android图片浏览代码： 
java代码： 
Java代码  
[font=宋体]package com.zx.imageswitcher;  
  
    import Android.app.Activity;  
    import Android.content.Context;  
    import Android.os.Bundle;  
    import Android.view.View;  
    import Android.view.ViewGroup;  
    import Android.view.animation.AnimationUtils;  
    import Android.widget.AdapterView;  
    import Android.widget.BaseAdapter;  
    import Android.widget.Gallery;  
    import Android.widget.ImageSwitcher;  
    import Android.widget.ImageView;  
    import Android.widget.ViewSwitcher;  
    import Android.widget.Gallery.LayoutParams;  
  
    public class ImageSwitcherTest extends Activity implements AdapterView.OnItemSelectedListener, ViewSwitcher.ViewFactory{  
    private ImageSwitcher mSwitcher;  
    private Integer[] mThumbIds = {  
    R.drawable.sample_thumb_0, R.drawable.sample_thumb_1, R.drawable.sample_thumb_2, R.drawable.sample_thumb_3, R.drawable.sample_thumb_4, R.drawable.sample_thumb_5, R.drawable.sample_thumb_6, R.drawable.sample_thumb_7};  
    private Integer[] mImageIds = {  
    R.drawable.sample_0, R.drawable.sample_1, R.drawable.sample_2, R.drawable.sample_3, R.drawable.sample_4, R.drawable.sample_5, R.drawable.sample_6, R.drawable.sample_7};  
    /** Called when the activity is first created. */  
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
    super.onCreate(savedInstanceState);  
    setContentView(R.layout.main);  
    mSwitcher = (ImageSwitcher) findViewById(R.id.switcher);  
    mSwitcher.setFactory(this);  
    mSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, Android.R.anim.fade_in)); mSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, Android.R.anim.fade_out));  
    Gallery g = (Gallery) findViewById(R.id.gallery);  
    g.setAdapter(new ImageAdapter(this));  
    g.setOnItemSelectedListener(this);  
    }  
    /* * override for ViewSwitcher.ViewFactory#makeView() */  
    public View makeView() {  
    ImageView i = new ImageView(this);  
    i.setBackgroundColor(0xFF000000);  
    i.setScaleType(ImageView.ScaleType.FIT_CENTER);  
    i.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));  
    return i;  
    }  
    /* 
    * override for 
    * AdapterView.OnItemSelectedListener#onItemSelected() 
    */  
    public void onItemSelected(AdapterView parent, View v, int position, long id) { mSwitcher.setImageResource(mImageIds[position]);  
    }  
    /* 
    * override for AdapterView.OnItemSelectedListener#onNothingSelected() 
    */  
    public void onNothingSelected(AdapterView< ?> arg0) {  
    // TODO Auto-generated method stub  
    }  
    public class ImageAdapter extends BaseAdapter {  
    public ImageAdapter(Context c) {  
    mContext = c;  
    }  
    public int getCount() {  
    return mThumbIds.length;  
    }  
    public Object getItem(int position) {  
    return position;  
    }  
    public long getItemId(int position) {  
    return position;  
    }  
    public View getView(int position, View convertView, ViewGroup parent) {  
    ImageView i = new ImageView(mContext);  
    i.setImageResource(mThumbIds[position]);  
    i.setAdjustViewBounds(true);  
    i.setLayoutParams(new Gallery.LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));  
    i.setBackgroundResource(R.drawable.picture_frame);  
    return i;  
    }  
    private Context mContext;  
    }  
  
    } [/font]

补充：移动开发 , Android ,