Android 通过文件管理器选择文件夹下面的文件以及获取路径

      今天要求用手机文件管理器选择文件夹下面的文件夹，并且可以创建新的文件夹，当然最后发现实现不了。不过还是把如何选择文件夹下面的文件以及获取到文件路径的方法记录下来，以备以后使用：

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button btn = (Button) findViewById(R.id.btn);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
                intent.setType("*/*");
                intent.addCategory(Intent.CATEGORY_OPENABLE);
                startActivityForResult(intent, 1);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (resultCode == Activity.RESULT_OK) {
            Uri uri = data.getData();
            if ("file".equalsIgnoreCase(uri.getScheme())){//使用第三方应用打开
                Toast.makeText(this,uri.getPath()+"11111",Toast.LENGTH_SHORT).show();
                return;
            }
            if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT) {//4.4以后
                String path = getPath(this, uri);
                Toast.makeText(this,path.toString(),Toast.LENGTH_SHORT).show();
            } else {//4.4一下系统调用方法
                Toast.makeText(MainActivity.this, getRealPathFromURI(uri)+"222222", Toast.LENGTH_SHORT).show();
            }
        }
    }

    public String getRealPathFromURI(Uri contentUri) {
        String res = null;
        String[] proj = { MediaStore.Images.Media.DATA };
        Cursor cursor = getContentResolver().query(contentUri, proj, null, null, null);
        if(null!=cursor&&cursor.moveToFirst()){;
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            res = cursor.getString(column_index);
            cursor.close();
        }
        return res;
    }

    /**
     * 专为Android4.4设计的从Uri获取文件绝对路径，以前的方法已不好使
     */
    @SuppressLint("NewApi")
    public String getPath(final Context context, final Uri uri) {

        final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

        // DocumentProvider
        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
            // ExternalStorageProvider
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                if ("primary".equalsIgnoreCase(type)) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                }
            }
            // DownloadsProvider
            else if (isDownloadsDocument(uri)) {

                final String id = DocumentsContract.getDocumentId(uri);
                final Uri contentUri = ContentUris.withAppendedId(
                        Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));

                return getDataColumn(context, contentUri, null, null);
            }
            // MediaProvider
            else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];

                Uri contentUri = null;
                if ("image".equals(type)) {
                    contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }

                final String selection = "_id=?";
                final String[] selectionArgs = new String[]{split[1]};

                return getDataColumn(context, contentUri, selection, selectionArgs);
            }
        }
        // MediaStore (and general)
        else if ("content".equalsIgnoreCase(uri.getScheme())) {
            return getDataColumn(context, uri, null, null);
        }
        // File
        else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }
        return null;
    }

    /**
     * Get the value of the data column for this Uri. This is useful for
     * MediaStore Uris, and other file-based ContentProviders.
     *
     * @param context       The context.
     * @param uri           The Uri to query.
     * @param selection     (Optional) Filter used in the query.
     * @param selectionArgs (Optional) Selection arguments used in the query.
     * @return The value of the _data column, which is typically a file path.
     */
    public String getDataColumn(Context context, Uri uri, String selection,
                                String[] selectionArgs) {

        Cursor cursor = null;
        final String column = "_data";
        final String[] projection = {column};

        try {
            cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
                    null);
            if (cursor != null && cursor.moveToFirst()) {
                final int column_index = cursor.getColumnIndexOrThrow(column);
                return cursor.getString(column_index);
            }
        } finally {
            if (cursor != null)
                cursor.close();
        }
        return null;
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is ExternalStorageProvider.
     */
    public boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }

布局文件什么的就不贴出来了，就一个button，希望对有需求的战友有帮助。