访问android媒体目录？

Question

ey up.我建立了一个简单的音乐应用程序,从SD卡读取wav文件并播放它们.我如何访问默认媒体目录？这就是我获得SD卡的方式

public void LoadSounds() throws IOException
    {
        String extState = Environment.getExternalStorageState();

         if(!extState.equals(Environment.MEDIA_MOUNTED)) {
             //handle error here
         }
         else {

         File sd = new File(Environment.getExternalStorageDirectory ()); //this needs to be a folder the user can access, like media

像往常一样,文档没有提供实际的使用示例,但它说明了这一点 - 如果您使用的是API级别8或更高级别,请使用getExternalFilesDir()打开一个文件,该文件代表应保存文件的外部存储目录.此方法采用type参数指定所需的子目录类型,例如DIRECTORY_MUSIC ...

我该如何使用它？谢谢

编辑:如果我尝试用文件路径字符串填充微调器数组,这会使它崩溃.

File path = getExternalFilesDir(Environment.DIRECTORY_MUSIC);
            File sd = new File(path, "/myFolder");

File[] sdDirList = sd.listFiles(new WavFilter()); 
         if (sdDirList != null)
         {   
             //sort the spinner 
            amountofiles = sdDirList.length;


             array_spinner=new String[amountofiles];
......
final Spinner s = (Spinner) findViewById(R.id.spinner1); //crashes here

        ArrayAdapter<?> adapter = new ArrayAdapter<Object>(this,
        android.R.layout.select_dialog_item, array_spinner);

EDIT2:好的,所以我做了这个测试,应该写一个txt文件到音乐目录.我运行应用程序,没有txt文件写在我能找到的设备上的任何地方.

 // Path to write files to
        String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC).getAbsolutePath();

        String fname = "mytest.txt";

        // Current state of the external media
        String extState = Environment.getExternalStorageState();

        // External media can be written onto
        if (extState.equals(Environment.MEDIA_MOUNTED))
        {
            try {
                // Make sure the path exists
                boolean exists = (new File(path)).exists();  
                if (!exists){ new File(path).mkdirs(); }  

                // Open output stream
                FileOutputStream fOut = new FileOutputStream(path + fname);

                fOut.write("Test".getBytes());

                // Close output stream
                fOut.flush();
                fOut.close();

            } catch (IOException ioe) {
                ioe.printStackTrace();
            }



    }

另一个编辑:我会得到这个工作!因此,如果我使用此行,它会在SD卡上创建一个名为"Musictest"的文件夹.不懂？

 String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC + "test").getAbsolutePath();

////////////////////////////////////////////////// //////////////////最终编辑:对,所以这将在设备音乐目录中查找名为test的文件夹.如果它不存在,它将被创建.(这里有一些修复,如果为空则出错)然后列出目录中的文件并将它们添加到数组中.

 public void LoadSounds() throws IOException
    {
        String extState = Environment.getExternalStorageState();
        // Path to write files to
            String path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_MUSIC + "/test").getAbsolutePath();

         if(!extState.equals(Environment.MEDIA_MOUNTED)) {
             //handle error here
         }
         else {
             //do your file work here 

                // Make sure the path exists
                boolean exists = (new File(path)).exists(); 
                //if not create it
                if (!exists){ new File(path).mkdirs(); }


         File sd = new File(path);
         //This will return an array with all the Files (directories and files)
         //in the external storage folder

         File[] sdDirList = sd.listFiles(); 

         if (sdDirList != null)
         {   
             //add the files to the spinner array
             array_spinnerLoad=new String[sdDirList.length];
             files = new String[sdDirList.length];

         for(int i=0;i<sdDirList.length;i++){

         array_spinnerLoad[i] = sdDirList[i].getName();
        files[i] = sdDirList[i].getAbsolutePath();
         }

         }
         }
    }

Answer 1

如文档中所述,getExternalFilesDir()返回File.File对象可以表示文件或目录.

因此:

File musicDirectory = new File( getExternalFilesDir(Environment.DIRECTORY_MUSIC));

会给你玩的对象.