16 读取音乐文件

• 所需权限

  <!--Sd读写权限  -->
      <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
      <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

• java代码:

  package com.qf.day16_contentresolver_music_demo3;
  
  import java.io.File;
  
  import android.annotation.SuppressLint;
  import android.app.Activity;
  import android.content.ContentResolver;
  import android.content.Intent;
  import android.database.Cursor;
  import android.net.Uri;
  import android.os.Bundle;
  import android.provider.MediaStore;
  import android.provider.MediaStore.Audio.Media;
  import android.view.View;
  import android.widget.AdapterView;
  import android.widget.AdapterView.OnItemClickListener;
  import android.widget.ListView;
  import android.widget.SimpleCursorAdapter;
  import android.widget.TextView;
  
  /**
   * 
   * 获取音乐
   *
   */
  public class MainActivity extends Activity {
  
      private ListView lv;
      private TextView tv;
  
      private ContentResolver contentResolver;
  
      //获取音频的Uri对象
      private Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
      SimpleCursorAdapter adapter;
      @SuppressLint("NewApi")
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
  
          lv = (ListView) findViewById(R.id.lv);
          tv = (TextView) findViewById(R.id.tv);
  
          contentResolver = getContentResolver();
  
          //获取Sd卡里音乐的数据  
          //Media._ID 如果要用SimpleCursorAdaptet必须要查找此字段
          //Media.DISPLAY_NAME 音乐名 XXX.MP4
          //Media.DATA 绝对路径 
          //Media.TITLE  音乐名 XXX
          Cursor cursor = contentResolver.query(uri, 
                  new String[]{Media._ID,
                  Media.DISPLAY_NAME,
                  Media.DATA,
                  Media.TITLE}, null, null, null);
  
           adapter = new SimpleCursorAdapter
                  (MainActivity.this, R.layout.item, 
                          cursor, new String[]{Media.DISPLAY_NAME,
                          Media.DATA,
                          Media.TITLE}, 
                          new int[]{R.id.tv_name,R.id.tv_data,R.id.tv_title},
                          SimpleCursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
  
  
          lv.setAdapter(adapter);
          lv.setEmptyView(tv);
  
          lv.setOnItemClickListener(new OnItemClickListener() {
  
              @Override
              public void onItemClick(AdapterView<?> parent, View view,
                      int position, long id) {
                  // TODO Auto-generated method stub
  
                  //获取当前位置的数据
                  Cursor c = (Cursor) adapter.getItem(position);
                  //获取音乐的 路径
                  String path = c.getString(c.getColumnIndex(Media.DATA));
  
                  //播放音乐
                  Intent intent= new Intent();
                  intent.setAction(Intent.ACTION_VIEW);
                  intent.setDataAndType(Uri.fromFile(new File(path)), "audio/*");
                  startActivity(intent);
              }
          });
      }
  
  
  }
  

• layout 布局代码:
  activity_main2.xml:

  <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:paddingBottom="@dimen/activity_vertical_margin"
      android:paddingLeft="@dimen/activity_horizontal_margin"
      android:paddingRight="@dimen/activity_horizontal_margin"
      android:paddingTop="@dimen/activity_vertical_margin"
      tools:context=".MainActivity" >
  
      <ListView
          android:id="@+id/lv"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
         />
  
      <TextView 
          android:id="@+id/tv"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:textSize="30sp"
          android:textColor="#f00"
          android:text="暂无数据"
          />
  
  </RelativeLayout>
  

  item.xml:
  填充list布局

  <?xml version="1.0" encoding="utf-8"?>
  <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent"
      android:layout_height="match_parent" >
  
      <ImageView
          android:id="@+id/iv"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:src="@drawable/ic_launcher" />
  
      <TextView
          android:id="@+id/tv_name"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_toRightOf="@id/iv"
          android:singleLine="true"
          android:text="aaa" />
  
      <TextView
          android:id="@+id/tv_data"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_below="@id/tv_name"
          android:layout_toRightOf="@id/iv"
          android:singleLine="true"
          android:text="aaa" />
  
      <TextView
          android:id="@+id/tv_title"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_below="@id/tv_data"
          android:layout_toRightOf="@id/iv"
          android:singleLine="true"
          android:text="aaa" />
  
  </RelativeLayout>