Question

我在SD卡上有mp3文件。如何在选择文件时从SD卡获取文件路径？

动态！...如果用户在列表视图中单击文件，其路径将获取变量以供使用。

public class PlayListActivity extends ListActivity {
    // Songs list
    public ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.playlist);    
        ArrayList<HashMap<String, String>> songsListData = new ArrayList<HashMap<String, String>>();    
        SongsManager plm = new SongsManager();
        // get all songs from sdcard
        this.songsList = plm.getPlayList();

        // looping through playlist
        for (int i = 0; i < songsList.size(); i++) {
            // creating new HashMap
            HashMap<String, String> song = songsList.get(i);

            // adding HashList to ArrayList
            songsListData.add(song);
        }    
        // Adding menuItems to ListView
        ListAdapter adapter = new SimpleAdapter(this, songsListData,
                R.layout.playlist_item, new String[] { "songTitle" }, new int[] {
                        R.id.songTitle });

        setListAdapter(adapter);

        // selecting single ListView item
        ListView lv = getListView();
        // listening to single listitem click
        lv.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                // getting listitem index
                int songIndex = position;

                // Starting new intent
                Intent in = new Intent(getApplicationContext(),
                        AndroidBuildingMusicPlayerActivity.class);
                // Sending songIndex to PlayerActivity
                in.putExtra("songIndex", songIndex);
                setResult(100, in);
                // Closing PlayListView
                finish();
            }
        });    
    }
}

Answer 1

我想你想从文件打开对话框中获取文件，请查看以下链接

参考：Choose File Dialog

您可以借助以下命令获取SD卡的路径：

String baseDir = Environment.getExternalStorageDirectory().getAbsolutePath();
String fileName = "myFile.mp3";

所以路径

String path  = baseDir + "/your folder(s)/" + fileName;

参考是：Android how to use Environment.getExternalStorageDirectory()

或者您可以尝试：

new File("/mnt/external_sd/your folder(s)../file.mp3");//get a file from SD card

参考：How can I get external SD card path for Android 4.0+?

Answer 2

您可以使用getExternalStorageDirectory()将SD卡的根目录作为File对象

Answer 3

要获取文件，您应该使用类似这样的文件

public static byte[] readFile (String file, Context c) throws IOException {
    File f = new
    File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC), file);
    if (f.exists())
        return readFile(f);
    else return new byte[0];
}

然后你可以用你得到的字节解码文件。

Answer 4

我认为此代码可以与您合作...尝试并跟随我的结果

公共类SongsManager {

final String MEDIA_PATH = new String("/sdcard/");
private ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();

// Constructor
public SongsManager(){

}

/**d
 * Function to read all mp3 files from sdcard
 * and store the details in ArrayList
 * */
public ArrayList<HashMap<String, String>> getPlayList(){
        File List[] = Environment.getExternalStorageDirectory().listFiles();  

    File home;

    int index=0;

        while(index<List.length)
        {
            home = new File(List[index].getAbsolutePath().toString());
            if (home.listFiles(new FileExtensionFilter()).length > 0) {
            for (File file : home.listFiles(new FileExtensionFilter())) {

                HashMap<String, String> song = new HashMap<String, String>();
                song.put("songTitle", file.getName().substring(0, (file.getName().length() - 4)));
                song.put("songPath", file.getPath());

                // Adding each song to SongList
                songsList.add(song);
            }
            index++;
        }
    }
    // return songs list array
    return songsList;
}



/**
 * Class to filter files which are having .mp3 extension
 * */
class FileExtensionFilter implements FilenameFilter {
    public boolean accept(File dir, String name) {
        return (name.endsWith(".mp3") || name.endsWith(".MP3"));
    }
}

}

Answer 5

我在4天后得到了解决方案。在Android（Java）中提供File类的路径时请注意以下几点：

使用内部路径（在android中调用外部）存储
```
String path="/storage/sdcard0/myfile.txt";
```
```
path="/storage/sdcard1/myfile.txt";
```

在清单文件中提及权限。

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

首先检查文件长度以确认。
检查ES文件资源管理器中有关sdcard0＆amp;的路径。 sdcard1与此相同或者......例如
```
File file=new File(path);
long=file.length(); //in Bytes
```

来自SD卡的文件路径

5 个答案: