android 54 播放音视频

package com.sxt.day07_09;

import java.util.ArrayList;
import java.util.HashMap;

import android.app.Activity;
import android.content.ContentResolver;
import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.provider.MediaStore.Video;
import android.provider.MediaStore.Video.Thumbnails;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.VideoView;

public class MainActivity extends Activity {
    ArrayList<HashMap<String, Object>> mVideos;//M
    Gallery mGallery;//V
    VideoAdapter mAdapter;//C，用于列表显示
    VideoView mVideoView;//预览视频控件
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getVideoInfo();
        initView();
        setListener();
    }

    private void setListener() {
        mGallery.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                HashMap<String, Object> video=mVideos.get(position);
                String path=video.get(Video.Media.DATA).toString();
                mVideoView.setVideoPath(path);//设置视频路径
                mVideoView.start();//播放
            }
        });
    }

    private void initView() {
        mVideoView=(VideoView) findViewById(R.id.vv);
        mGallery=(Gallery) findViewById(R.id.gallery);
        mAdapter=new VideoAdapter(mVideos, this);//M添加到
        mGallery.setAdapter(mAdapter);
    }

    private void getVideoInfo() {
        ContentResolver resolver = getContentResolver();
        String[] projection={
            Video.Media._ID,//拿到略缩图
            Video.Media.DATA,//sd卡路径
            Video.Media.TITLE
        };
        mVideos=new ArrayList<HashMap<String,Object>>();
        //查询的是安卓数据库，数据库存的是多媒体文件的信息
        Cursor c = resolver.query(Video.Media.EXTERNAL_CONTENT_URI, projection, null, null, null);
        while(c.moveToNext()){
            HashMap<String, Object> video=new HashMap<String, Object>();
            video.put(Video.Media._ID, c.getInt(c.getColumnIndex(Video.Media._ID)));
            video.put(Video.Media.DATA, c.getString(c.getColumnIndex(Video.Media.DATA)));
            video.put(Video.Media.TITLE, c.getString(c.getColumnIndex(Video.Media.TITLE)));
            mVideos.add(video);
        }
    }

    //适配器，用于列表显示
    class VideoAdapter extends BaseAdapter{
        ArrayList<HashMap<String, Object>> videos;
        Context context;
        
        public VideoAdapter(ArrayList<HashMap<String, Object>> videos,
                Context context) {
            super();
            this.videos = videos;
            this.context = context;
        }

        @Override
        public int getCount() {
            return videos.size();
        }

        @Override
        public Object getItem(int position) {
            // TODO Auto-generated method stub
            return null;
        }

        @Override
        public long getItemId(int position) {
            // TODO Auto-generated method stub
            return 0;
        }

        @Override
        //没有用缓存做优化
        public View getView(int position, View layout, ViewGroup parent) {
            layout=View.inflate(context, R.layout.item_video, null);
            ImageView ivThumb=(ImageView) layout.findViewById(R.id.ivThumb);//显示视频略缩图
            TextView tvTitle=(TextView) layout.findViewById(R.id.tvTitle);//视频标题
            HashMap<String, Object> video=videos.get(position);
            tvTitle.setText(video.get(Video.Media.TITLE).toString());
            int id=(Integer) video.get(Video.Media._ID);
            //Thumbnails类用于获取视频或者图片的略缩图，
            Bitmap bm=Thumbnails.getThumbnail(getContentResolver(), id, Thumbnails.MICRO_KIND, null);
            ivThumb.setImageBitmap(bm);
            return layout;
        }
    }
}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <Gallery                                    水平滚动
        android:id="@+id/gallery"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    <VideoView                             预览播放视频控件
        android:id="@+id/vv"
        android:layout_below="@id/gallery"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</RelativeLayout>

item_view.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical" >
    
    <ImageView                                 每一项布局
        android:id="@+id/ivThumb"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:src="@drawable/ic_launcher"/>
    <TextView 
        android:id="@+id/tvTitle"
        android:layout_width="80dp"
        android:layout_height="wrap_content"
        android:text="安卓"
        android:gravity="center_horizontal"/>
</LinearLayout>