Flutter Flie本地文件读写

获取临时存储路径

 void _requestTempDirectory() async {
    Directory tempDir = await getTemporaryDirectory();
    setState(() {
      tempPath = tempDir.path;
    });
  }

往文件写数据

  _add() async {

    File file = new File('$tempPath/user.txt');
    await file.writeAsString('用户名:$username\n密码:$pwd');
    setState(() {
      _result = '写入成功，请查询';
    });
  }

读取文件数据

 _query() async {
    try {
      File file = new File('$tempPath/user.txt');
      _result = '查询成功\n' + await file.readAsString();
    } on Exception catch (e) {
      _result = ' exception: $e';
    }

    setState(() {});
  }

删除

  _delete() {
    File file = new File('$tempPath/user.txt');
    file.deleteSync(recursive: false);
    setState(() {
      _result = '删除成功，请查看';
    });
  }