android 视频缩略图之 MediaStore

首先 声明MediaStore是2.0以后才有的类

listview.xml如下

 xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:orientation="horizontal"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     >
     <ImageView
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:id="@+id/iv"
         />
     <TextView
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:id="@+id/tv"
         />
 LinearLayout>

1、我先按照参考的第一个url来写的 

 package com.lp;

 import java.util.ArrayList;

 import android.app.ListActivity;
 import android.content.Context;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.Bundle;
 import android.provider.MediaStore;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.BaseAdapter;
 import android.widget.ImageView;
 import android.widget.TextView;
 /**
  * 本实例，我们将通过检索SDCard上的Video信息
  * 在MediaStore中，MediaStore.Video.Media中就有Video相关信息，
  * 同时MediaStore.Video.Thumbnails中含有各个video对应的缩略图信息
  *
  * @author Administrator
  *
  */
 public class MainActivity extends ListActivity {

     private Cursor cursor;
     private ArrayList videoList = new ArrayList();
     private ImageView img;

     public void onCreate(Bundle savedInstanceState){
         super.onCreate(savedInstanceState);
         init();
     }


     private void init(){
         String[] thumbColumns = new String[]{
                 MediaStore.Video.Thumbnails.DATA,
                 MediaStore.Video.Thumbnails.VIDEO_ID
         };

         String[] mediaColumns = new String[]{
                 MediaStore.Video.Media.DATA,
                 MediaStore.Video.Media._ID,
                 MediaStore.Video.Media.TITLE,
                 MediaStore.Video.Media.MIME_TYPE
         };

         //首先检索SDcard上所有的video
         cursor = this.managedQuery(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, mediaColumns, null, null, null);


         while(cursor.moveToNext()){
                 VideoInfo info = new VideoInfo();

                 info.filePath = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DATA));
                 info.mimeType = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.MIME_TYPE));
                 info.title = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.TITLE));

                 //获取当前Video对应的Id，然后根据该ID获取其Thumb
                 int id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID));
                 String selection = MediaStore.Video.Thumbnails.VIDEO_ID +"=?";
                 String[] selectionArgs = new String[]{
                         id+""
                 };
                 Cursor thumbCursor = this.managedQuery(MediaStore.Video.Thumbnails.EXTERNAL_CONTENT_URI, thumbColumns, selection, selectionArgs, null);

                 if(thumbCursor.moveToFirst()){
                     info.thumbPath = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Thumbnails.DATA));

                 }
                 //然后将其加入到videoList
                 videoList.add(info);

         }
         System.out.println(videoList.size());
         //然后需要设置ListView的Adapter了，使用我们自定义的Adatper
         VideoAdapter adapter = new VideoAdapter(this);
         this.getListView().setAdapter(adapter);
     }


     class VideoInfo{
         String filePath;
         String mimeType;
         String thumbPath;
         String title;
     }

     class ViewHolder{
         ImageView thumbImage;
         TextView titleText;
     }

     /**
      * 定义一个Adapter来显示缩略图和视频title信息
      * @author Administrator
      *
      */
     private class VideoAdapter extends BaseAdapter{

         private Context mContext;
         private LayoutInflater inflater;

         public VideoAdapter(Context context){
             this.mContext = context;
             this.inflater = LayoutInflater.from(context);
             this.inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         }
         @Override
         public int getCount() {
             // TODO Auto-generated method stub
             return videoList.size();
         }
         @Override
         public Object getItem(int p) {
             // TODO Auto-generated method stub
             return videoList.get(p);
         }
         @Override
         public long getItemId(int p) {
             // TODO Auto-generated method stub
             return p;
         }
         @Override
         public View getView(int position, View convertView, ViewGroup parent) {
             ViewHolder holder ;
             if(convertView == null){
                 holder = new ViewHolder();
                 convertView = inflater.inflate(R.layout.listview, null);
                 holder.thumbImage = (ImageView)convertView.findViewById(R.id.iv);
                 holder.titleText = (TextView)convertView.findViewById(R.id.tv);
                 convertView.setTag(holder);
             }else{
                 holder = (ViewHolder)convertView.getTag();
             }

             //显示信息
             holder.titleText.setText(videoList.get(position).title);
             if(videoList.get(position).thumbPath != null){
                 holder.thumbImage.setImageURI(Uri.parse(videoList.get(position).thumbPath));
             }

             return convertView;
         }

     }
 }

但是 结果是能得到title 得不到缩略图 貌似大家都说好使  但是我这里就是不行 很是纳闷 

后来 我就直接看了下com.android.providers.media下面的external-ef8261f.db

数据库的结构如下图：

video

这里面罗列的sdcard的所有视频文件 我们可以得到 名字 类型 持续时间 大小等有用的数据

再看一下 videothumbnails

这里面是没有数据的！！！ 这个就是原因了
所以我们根据VIDEO_ID在videothumbnails表里面肯定是什么也得不到的

2、

仔细查看MediaStore.Video.Thumbnails类里面的方法 可以发现 提供了一个getThumbnail()方法 可以直接得到缩略图 

 package com.lp;

 import java.util.ArrayList;

 import android.app.ListActivity;
 import android.content.Context;
 import android.database.Cursor;
 import android.net.Uri;
 import android.os.Bundle;
 import android.provider.MediaStore;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.BaseAdapter;
 import android.widget.ImageView;
 import android.widget.TextView;
 /**
  * 本实例，我们将通过检索SDCard上的Video信息
  * 在MediaStore中，MediaStore.Video.Media中就有Video相关信息，
  * 同时MediaStore.Video.Thumbnails中含有各个video对应的缩略图信息
  *
  * @author Administrator
  *
  */
 public class MainActivity extends ListActivity {

     private Cursor cursor;
     private ArrayList videoList = new ArrayList();
     private ImageView img;

     public void onCreate(Bundle savedInstanceState){
         super.onCreate(savedInstanceState);
         init();
     }


     private void init(){
         String[] thumbColumns = new String[]{
                 MediaStore.Video.Thumbnails.DATA,
                 MediaStore.Video.Thumbnails.VIDEO_ID
         };

         String[] mediaColumns = new String[]{
                 MediaStore.Video.Media.DATA,
                 MediaStore.Video.Media._ID,
                 MediaStore.Video.Media.TITLE,
                 MediaStore.Video.Media.MIME_TYPE
         };

         //首先检索SDcard上所有的video
         cursor = this.managedQuery(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, mediaColumns, null, null, null);


         while(cursor.moveToNext()){
                 VideoInfo info = new VideoInfo();

                 info.filePath = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.DATA));
                 info.mimeType = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.MIME_TYPE));
                 info.title = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Video.Media.TITLE));

                 //获取当前Video对应的Id，然后根据该ID获取其Thumb
                 int id = cursor.getInt(cursor.getColumnIndexOrThrow(MediaStore.Video.Media._ID));
                 BitmapFactory.Options options = new BitmapFactory.Options();
                 options.inDither = false;
                 options.inPreferredConfig = Bitmap.Config.ARGB_8888;
                 info.b = MediaStore.Video.Thumbnails.getThumbnail(getContentResolver(), id,  Images.Thumbnails.MICRO_KIND, options);
                 //然后将其加入到videoList
                 videoList.add(info);

         }
         System.out.println(videoList.size());
         //然后需要设置ListView的Adapter了，使用我们自定义的Adatper
         VideoAdapter adapter = new VideoAdapter(this);
         this.getListView().setAdapter(adapter);
     }

     class VideoInfo{
         String filePath;
         String mimeType;
         Bitmap b;
         String title;
     }

     class ViewHolder{
         ImageView thumbImage;
         TextView titleText;
     }

     /**
      * 定义一个Adapter来显示缩略图和视频title信息
      * @author Administrator
      *
      */
     private class VideoAdapter extends BaseAdapter{

         private Context mContext;
         private LayoutInflater inflater;

         public VideoAdapter(Context context){
             this.mContext = context;
             this.inflater = LayoutInflater.from(context);
             this.inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
         }
         @Override
         public int getCount() {
             // TODO Auto-generated method stub
             return videoList.size();
         }
         @Override
         public Object getItem(int p) {
             // TODO Auto-generated method stub
             return videoList.get(p);
         }
         @Override
         public long getItemId(int p) {
             // TODO Auto-generated method stub
             return p;
         }
         @Override
         public View getView(int position, View convertView, ViewGroup parent) {
             ViewHolder holder ;
             if(convertView == null){
                 holder = new ViewHolder();
                 convertView = inflater.inflate(R.layout.listview, null);
                 holder.thumbImage = (ImageView)convertView.findViewById(R.id.iv);
                 holder.titleText = (TextView)convertView.findViewById(R.id.tv);
                 convertView.setTag(holder);
             }else{
                 holder = (ViewHolder)convertView.getTag();
             }

             //显示信息
             holder.titleText.setText(videoList.get(position).title);
             if(videoList.get(position).b != null){
                 holder.thumbImage.setImageBitmap(videoList.get(position).b);
             }

             return convertView;
         }

     }
 }

从video表里面得到关于视频的一些数据，如：时间、大小、类型等
2、我们可以通过

 MediaStore.Video.Thumbnails.getThumbnail(getContentResolver(), id,  Images.Thumbnails.MICRO_KIND, options);

直接得到缩略图


代码见附件

转载：http://lipeng88213.iteye.com/blog/1182265