Flutter:如何从简单的电子表格中读取数据? [英] Flutter: How to read data from simple spreadsheet?

问题描述

我是扑朔迷离的新手，并且有一个不难为专业人士回答的问题.

I am new to flutter and a have question that shouldn't be to hard to answer for a pro.

我有一个简单的电子表格，其中包含5列10行.现在，我有两个变量，分别代表列索引和行索引.

I have a simple spreadsheet with 5 columns and 10 rows. Now I have two variables, representing column and row index.

我想简单地从电子表格中读取相应的值，具体取决于所需的列和行号.

I want to simply read the corresponding value out of the spreadsheet, depending on the wanted column and row numbers.

这可能是扑扑吗? Flutter可以阅读电子表格(例如.csv)并以某种方式获取信息吗?

Is this possible with flutter? Can flutter read a spreadsheet (.csv e.g.) and somehow get the information out of it?

我期待着一个答案，谢谢！

I'm looking forward to an answer, thank you!

这是我到目前为止的代码，最初来自 https://flutter.io/cookbook/persistence/reading-writing-files/. 它会打印

This is the code I have so far, originally from https://flutter.io/cookbook/persistence/reading-writing-files/. It prints

I/flutter(18817):未来"的实例

I/flutter (18817): Instance of 'Future'

但是我不知道如何访问数据.

but I don't know how to access the data.

Future<String> readTable() async {
    try {
      final file = File("assets/res/table.txt");

      // Read the file
      String contents = await file.readAsString();
      print(contents);
      return contents;
    } catch (e) {
      // If we encounter an error, return 0
      return "";
    }
  }

推荐答案

感谢您的回答.我使用async和await使其工作，如下所示.同样重要的是像

Thanks for your answers. I made it work using async and await as can be seen in the following. Important as well is to declare the asset file in your pubspec.yaml like

flutter:
  assets:
    - assets/res/Book1.csv

然后声明这两个函数，并在要加载数据时调用loadCSV().

Then declare both functions and just call loadCSV() when you want to load the data.

Future<String> loadAsset(String path) async {
   return await rootBundle.loadString(path);
}

void loadCSV() {
  loadAsset('assets/res/Book1.csv').then((dynamic output) {
    csvRaw = output;
  });
}

希望这可以帮助遇到相同问题的任何人.

Hope this helps anyone having the same problem.

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