一、開啟系統自帶的檔案管理器

       if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {
            showToast(R.string.msg_storage_nosdcard);
            return;
        }
        //獲取檔案下載路徑
        String compName = AppString.getCompanyName();
        String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + compName + "/OSC_DATA/";
        File dir = new File(path);
        if (!dir.exists()) {
            dir.mkdirs();
        }
        //呼叫系統檔案管理器開啟指定路徑目錄
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        intent.setDataAndType(Uri.fromFile(dir.getParentFile()), "file/*.txt");
        intent.addCategory(Intent.CATEGORY_OPENABLE);
        startActivityForResult(intent, REQUEST_CHOOSEFILE);
 

@Override
protected void onActivityResult(int requestCode,int resultCode,Intent data){//選擇檔案返回
        super.onActivityResult(requestCode,resultCode,data);
        if(resultCode==RESULT_OK){
        switch(requestCode){
              case REQUEST_CHOOSEFILE:
              Uri uri=data.getData();
              chooseFilePath=FileChooseUtil.getInstance(this).getChooseFileResultPath(uri);
             Log.d(TAG,"選擇檔案返回："+chooseFilePath);
              sendFileMessage(chooseFilePath);
              break;
        }
    }
}
 

二、工具類FileChooseUtil

public class FileChooseUtil {

    private Context context;
    private static FileChooseUtil util = null;

    private FileChooseUtil(Context context) {
        this.context = context;
    }

    public static FileChooseUtil getInstance(Context context) {
        if (util == null) {
            util = new FileChooseUtil(context);
        }
        return util;
    }

    /**
     * 對外介面  獲取uri對應的路徑
     *
     * @param uri
     * @return
     */
    public String getChooseFileResultPath(Uri uri) {
        String chooseFilePath = null;
        if ("file".equalsIgnoreCase(uri.getScheme())) {//使用第三方應用開啟
            chooseFilePath = uri.getPath();
            Toast.makeText(context, chooseFilePath, Toast.LENGTH_SHORT).show();
            return chooseFilePath;
        }
        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.KITKAT) {//4.4以後
            chooseFilePath = getPath(context, uri);
        } else {//4.4以下下系統呼叫方法
            chooseFilePath = getRealPathFromURI(uri);
        }
        return chooseFilePath;
    }

    private String getRealPathFromURI(Uri contentUri) {
        String res = null;
        String[] proj = {MediaStore.Images.Media.DATA};
        Cursor cursor = context.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;
    }

    /**
     * 專為Android4.4設計的從Uri獲取檔案絕對路徑，以前的方法已不好使
     */
    @SuppressLint("NewApi")
    private 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())) {
            uri.getPath();

        }
        return null;
    }

    private 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.
     */
    private 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.
     */
    private 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.
     */
    private boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }
}
 

完！！！