安卓学习之检索MediaStore中的Video和其对应的缩略图信息

雨点打透心脏的1/2处 2022-03-27 02:50 69阅读 0赞

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：

[java] view plaincopyprint?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;  
            }  
              
        }  
    }