安卓编程如何实现获取本机中所有图片

本示例演示如何在Android中实现获取本机中的所有图片，并进行查看效果。

在这个示例中，我使用android-support-v4.jar中的加载器来实现获取本机中所有图片，关于这个包在以前的文章中也提到，是一个非常有用的包。

先让我们看下本示例实现的效果图：

项目结构图如下所示：

MyDevicePhotoActivity.java文件中代码如下：

package com.device.photo;import android.app.Dialog;import android.content.ContentResolver;import android.database.Cursor;import android.graphics.Bitmap;import android.net.Uri;import android.os.Bundle;import android.provider.MediaStore;import android.view.View;import android.view.View.OnClickListener;import android.widget.AdapterView;import android.widget.Button;import android.widget.ImageView;import android.widget.ListView;import android.widget.TextView;import android.widget.AdapterView.OnItemClickListener;import android.support.v4.app.FragmentActivity;import android.support.v4.app.LoaderManager.LoaderCallbacks;import android.support.v4.content.CursorLoader;import android.support.v4.content.Loader;import android.support.v4.widget.SimpleCursorAdapter;import android.support.v4.widget.SimpleCursorAdapter.ViewBinder;/*** Android实现获取本机中所有图片* @Description: Android实现获取本机中所有图片* @FileName: MyDevicePhotoActivity.java * @Package com.device.photo * @Author Hanyonglu* @Date 2012-5-10 下午04:43:55 * @Version V1.0*/public class MyDevicePhotoActivity extends FragmentActivity implements LoaderCallbacks{ private Bitmap bitmap = null; private byte[] mContent = null; private ListView listView = null; private SimpleCursorAdapter simpleCursorAdapter = null; private static final String[] STORE_IMAGES = { MediaStore.Images.Media.DISPLAY_NAME, MediaStore.Images.Media.LATITUDE, MediaStore.Images.Media.LONGITUDE, MediaStore.Images.Media._ID }; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); listView = (ListView)findViewById(android.R.id.list); simpleCursorAdapter = new SimpleCursorAdapter( this, R.layout.simple_list_item, null, STORE_IMAGES, new int[] { R.id.item_title, R.id.item_value}, 0 ); simpleCursorAdapter.setViewBinder(new ImageLocationBinder()); listView.setAdapter(simpleCursorAdapter); // 注意此处是getSupportLoaderManager()，而不是getLoaderManager()方法。

getSupportLoaderManager().initLoader(0, null, this); // 单击显示图片 listView.setOnItemClickListener(new ShowItemImageOnClickListener()); } @Override public Loader onCreateLoader(int arg0, Bundle arg1) { // TODO Auto-generated method stub // 为了查看信息，需要用到CursorLoader。

CursorLoader cursorLoader = new CursorLoader( this, MediaStore.Images.Media.EXTERNAL_CONTENT_URI, STORE_IMAGES, null, null, null); return cursorLoader; } @Override public void onLoaderReset(Loader arg0) { // TODO Auto-generated method stub simpleCursorAdapter.swapCursor(null); } @Override public void onLoadFinished(Loader arg0, Cursor cursor) { // TODO Auto-generated method stub // 使用swapCursor()方法，以使旧的游标不被关闭． simpleCursorAdapter.swapCursor(cursor); } // 将图片的位置绑定到视图 private class ImageLocationBinder implements ViewBinder{ @Override public boolean setViewValue(View view, Cursor cursor, int arg2) { // TODO Auto-generated method stub if (arg2 == 1) { // 图片经度和纬度 double latitude = cursor.getDouble(arg2); double longitude = cursor.getDouble(arg2 + 1); if (latitude == 0.0 && longitude == 0.0) { ((TextView)view).setText("位置：未知"); } else { ((TextView)view).setText("位置：" + latitude + ", " + longitude); } // 需要注意：在使用ViewBinder绑定数据时，必须返回真；否则，SimpleCursorAdapter将会用自己的方式绑定数据。

return true; } else { return false; } } } // 单击项显示图片事件监听器 private class ShowItemImageOnClickListener implements OnItemClickListener{ @Override public void onItemClick(AdapterView ?> parent, View view, int position, long id) { // TODO Auto-generated method stub final Dialog dialog = new Dialog(MyDevicePhotoActivity.this); // 以对话框形式显示图片 dialog.setContentView(R.layout.image_show); dialog.setTitle("图片显示"); ImageView ivImageShow = (ImageView) dialog.findViewById(R.id.ivImageShow); Button btnClose = (Button) dialog.findViewById(R.id.btnClose); btnClose.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { dialog.dismiss(); } }); Uri uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI.buildUpon(). appendPath(Long.toString(id)).build(); FileUtil file = new FileUtil(); ContentResolver resolver = getContentResolver(); // 从Uri中读取图片资源 try { mContent = file.readInputStream(resolver.openInputStream(Uri.parse(uri.toString()))); bitmap = file.getBitmapFromBytes(mContent, null); ivImageShow.setImageBitmap(bitmap); } catch (Exception e) { // TODO: handle exception e.printStackTrace(); } dialog.show(); } }}

FileUtil.java文件主要是对图片资源的处理。

代码如下：

package com.device.photo;import java.io.ByteArrayOutputStream;import java.io.InputStream;import android.graphics.Bitmap;import android.graphics.BitmapFactory;/*** 文件操作类* @Description: 文件操作类* @FileName: FileUtil.java * @Package com.device.photo * @Author Hanyonglu* @Date 2012-5-10 下午01:37:49 * @Version V1.0*/public class FileUtil { public FileUtil() { // TODO Auto-generated constructor stub } /** * InputStream to byte * @param inStream * @return * @throws Exception */ public byte[] readInputStream(InputStream inStream) throws Exception { byte[] buffer = new byte[1024]; int len = -1; ByteArrayOutputStream outStream = new ByteArrayOutputStream(); while ((len = inStream.read(buffer)) != -1) { outStream.write(buffer, 0, len); } byte[] data = outStream.toByteArray(); outStream.close(); inStream.close(); return data; } /** * Byte to bitmap * @param bytes * @param opts * @return */ public Bitmap getBitmapFromBytes(byte[] bytes, BitmapFactory.Options opts) { if (bytes != null){ if (opts != null){ return BitmapFactory.decodeByteArray(bytes, 0, bytes.length,opts); } else{ return BitmapFactory.decodeByteArray(bytes, 0, bytes.length); } } return null; } }