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

[html] view
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<?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

[java] view
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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

[java] view
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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

Java代码


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