private void getEbookList(){
	String[] columns = new String[] {
		MediaStore.Files.FileColumns.TITLE,
		MediaStore.Files.FileColumns.DATA
	};
	Uri uri = MediaStore.Files.getContentUri("external");
	String selection = "(" + MediaStore.Files.FileColumns.MIME_TYPE + "=='text/plain')";
	Cursor c = getContentResolver().query(uri, columns, selection, null, MediaStore.Files.FileColumns.SIZE + " DESC");
	if (c == null) return;
 
	if (c.moveToFirst()) {
		int dataIndex = c.getColumnIndex(MediaStore.Files.FileColumns.DATA);
		int titleIndex = c.getColumnIndex(MediaStore.Files.FileColumns.TITLE);
		do {
 			c.getString(titleIndex); // 获取文件名，不包含扩展名
			c.getString(dataIndex);  // 获取文件实际路径
 		} while (c.moveToNext()); // 循环获取文件
	}
	c.close();}