Android实现简单的相册

用手机浏览靓照也是件非常惬意的事了，然而如何实现这一功能呢，其实也并不难，下面是一个简单的例子，功能为：主屏幕上显示用户选择的靓照，屏幕下面滚动显示靓照集，点击即可浏览。如下图所示:

实现代码为：（这里图片没法提供了，可以设置自己喜欢的图片，R.drawable.photo1为图片标志，这里图片存放在res\drawable目录下，图片名为photo1，我所建工程的包结构为：cn.com.pan，有两个Activity和对应的两个布局文件。）

-----------------------MainActivity ----------------------------------------

import android.widget.*;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
public class MainActivity extends Activity {
 OnClickListener listener0 = null;
 private Button button0;
 private Button button1;
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  //单击按钮跳转到photoActivity
  listener0 = new OnClickListener() {
   public void onClick(View v) {
    Intent intent = new Intent(MainActivity.this,
      PhotoActivity.class);
    startActivity(intent);
   }
  };
  button0 = (Button) findViewById(R.id.showbutton);
  button0.setOnClickListener(listener0);
  button1 = (Button) findViewById(R.id.exitbutton);
  //单击退出
  button1.setOnClickListener(new OnClickListener(){
   @Override
   public void onClick(View v) {
    // TODO Auto-generated method stub
    finish();
   }
  });
 }
}

----------------------------------PhotoActivity ---------------------------------

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.view.Window;
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.AdapterView.OnItemSelectedListener;
import android.widget.RelativeLayout.LayoutParams;
import android.widget.ViewSwitcher.ViewFactory;
public class PhotoActivity extends Activity implements ViewFactory,
  OnItemSelectedListener {
 ImageSwitcher mSwitcher;
 private Integer[] mThumbIds = { R.drawable.photo1, R.drawable.photo2,
   R.drawable.photo6,R.drawable.photo4, R.drawable.photo5,R.drawable.photo3};
 private Integer[] mImageIds = { R.drawable.photo1, R.drawable.photo2,
   R.drawable.photo6 ,R.drawable.photo4, R.drawable.photo5,R.drawable.photo3};
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  requestWindowFeature(Window.FEATURE_NO_TITLE);
  setContentView(R.layout.showphoto);
  mSwitcher = (ImageSwitcher) findViewById(R.id.ImageSwitcher01);
  //系统的anim中的fade_in.xml
  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);
  //为缩略图浏览器指定一个适配器
  g.setAdapter(new ImageAdapter(this));
  //响应在缩略图列表上选中某个缩略图后的事件
  g.setOnItemSelectedListener(this);
 }
 @SuppressWarnings("unchecked")
 public void onItemSelected(AdapterView parent, View v, int position, long id) {
  mSwitcher.setImageResource(mImageIds[position]);
 }
 @SuppressWarnings("unchecked")
 public void onNothingSelected(AdapterView parent) {
 }
 @Override
 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;
 }
 public class ImageAdapter extends BaseAdapter {
  private Context mContext;
  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;
  }
  //getView方法动态生成一个 ImageView,然后利用setLayoutParams,setImageResource,setBackgroundResource
  //分别设定图片大小、图片源文件和图片背景。当图片被显示到当前
  //屏幕的时候，这个函数就会被自动回调来提供要显示的 ImageView
  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.photo3);
   return i;
  }
 }
}
--------------------------------main.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="fill_parent"
    >
    <Button android:id="@+id/showbutton"
           android:text="查看图片"
              android:layout_width="wrap_content"
            android:layout_height="wrap_content">
        </Button>
    <Button android:id="@+id/exitbutton"
           android:text="退出"
              android:layout_width="wrap_content"
            android:layout_height="wrap_content">
        </Button>
</LinearLayout>
-------------------------------showphoto.xml----------------------------------------

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent" android:layout_height="fill_parent">
 <ImageSwitcher android:id="@+id/ImageSwitcher01"
  android:layout_height="fill_parent" android:layout_width="fill_parent"
  android:layout_alignParentTop="true" android:layout_alignParentLeft="true">
 </ImageSwitcher>
 <Gallery android:id="@+id/gallery" android:background="#abcdef"
  android:layout_width="fill_parent" android:layout_height="60dp"
  android:layout_alignParentBottom="true"
  android:layout_alignParentLeft="true" android:gravity="center_vertical"
  android:spacing="15dp" />
</RelativeLayout>

--------------------------------AndroidManifest.xml-------------------------------------

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="fill_parent" android:layout_height="fill_parent">
 <ImageSwitcher android:id="@+id/ImageSwitcher01"
  android:layout_height="fill_parent" android:layout_width="fill_parent"
  android:layout_alignParentTop="true" android:layout_alignParentLeft="true">
 </ImageSwitcher>
 <Gallery android:id="@+id/gallery" android:background="#abcdef"
  android:layout_width="fill_parent" android:layout_height="60dp"
  android:layout_alignParentBottom="true"
  android:layout_alignParentLeft="true" android:gravity="center_vertical"
  android:spacing="15dp" />
</RelativeLayout>