Android多媒体学习十三：检索MediaStore中的Video和其对应的缩略图信息

和Image，Audio一样，在Android中，Video信息也被MediaStore管理着。

和每个视频对应的有其一个缩略图，这个缩略图往往是其第一帧的图像。

下面看代码：

package demo.camera; import java.util.ArrayList; import java.util.List; 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 AdvancedVideoDemo extends ListActivity { private Cursor cursor; public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.video_advanced); 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); ArrayList<VideoInfo> videoList = new ArrayList<AdvancedVideoDemo.VideoInfo>(); if(cursor.moveToFirst()){ do{ 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); }while(cursor.moveToNext()); } //然后需要设置ListView的Adapter了，使用我们自定义的Adatper VideoAdapter adapter = new VideoAdapter(this, videoList); this.getListView().setAdapter(adapter); } static class VideoInfo{ String filePath; String mimeType; String thumbPath; String title; } /** * 定义一个Adapter来显示缩略图和视频title信息 * @author Administrator * */ static class VideoAdapter extends BaseAdapter{ private Context context; private List<VideoInfo> videoItems; public VideoAdapter(Context context, List<VideoInfo> data){ this.context = context; this.videoItems = data; } @Override public int getCount() { // TODO Auto-generated method stub return videoItems.size(); } @Override public Object getItem(int p) { // TODO Auto-generated method stub return videoItems.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 = null; if(convertView == null){ holder = new ViewHolder(); convertView = LayoutInflater.from(context).inflate(R.layout.video_item, null); holder.thumbImage = (ImageView)convertView.findViewById(R.id.thumb_image); holder.titleText = (TextView)convertView.findViewById(R.id.video_title); convertView.setTag(holder); }else{ holder = (ViewHolder)convertView.getTag(); } //显示信息 holder.titleText.setText(videoItems.get(position).title); if(videoItems.get(position).thumbPath != null){ holder.thumbImage.setImageURI(Uri.parse(videoItems.get(position).thumbPath)); } return convertView; } class ViewHolder{ ImageView thumbImage; TextView titleText; } } }