2011.09.28——— android 视频缩略图之 MediaStore

2011.09.28——— android 视频缩略图之 MediaStore

参考： http://blog.csdn.net/chenjie19891104/article/details/6338910
http://www.eoeandroid.com/thread-51855-1-1.html

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<VideoInfo> videoList = new ArrayList<MainActivity.VideoInfo>();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videocursor = 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Thumbint 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videoListvideoList.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AdatperVideoAdapter 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);  }@Overridepublic int getCount() {// TODO Auto-generated method stubreturn videoList.size();}@Overridepublic Object getItem(int p) {// TODO Auto-generated method stubreturn videoList.get(p);}@Overridepublic long getItemId(int p) {// TODO Auto-generated method stubreturn p;}@Overridepublic 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：

2011.09.28——— android 视频缩略图之 MediaStore_第1张图片

2011.09.28——— android 视频缩略图之 MediaStore_第1张图片

这个就不介绍了看下名字应该就明白了
我们直接看video和videothumbnails 问题就在这里

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<VideoInfo> videoList = new ArrayList<MainActivity.VideoInfo>();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videocursor = 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Thumbint 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videoListvideoList.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AdatperVideoAdapter 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);  }@Overridepublic int getCount() {// TODO Auto-generated method stubreturn videoList.size();}@Overridepublic Object getItem(int p) {// TODO Auto-generated method stubreturn videoList.get(p);}@Overridepublic long getItemId(int p) {// TODO Auto-generated method stubreturn p;}@Overridepublic 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;}}}

哈哈图片显示出来了证明这样是可行的

所以结论是：
1、我们可以通过

managedQuery(MediaStore.Video.Media.EXTERNAL_CONTENT_URI, mediaColumns, null, null, null);

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

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