信息未寫入文本文件

Question

由於某種原因，此方法返回的文件為零字節。 它應該創建一個文件並返回一個列表。 它會返回到控制台，但不會寫入文件。

這是電話

data.GetStationIDs ("BoulderStations.txt", lat, lon);

這是方法

public List<string> GetStationIDs (string filename, string lat, string lon) {

        //specify file name, instructions, and priveleges
        FileStream CurrentDataFile = new FileStream (filename, FileMode.OpenOrCreate, FileAccess.Write);
        //create a new stream to write to the file
        StreamWriter CurrentData = new StreamWriter (CurrentDataFile);

        List<string> StationIDList = new List<string>();

        string url = @"http://api.wunderground.com/api/" + wundergroundkey + "/geolookup/q/" + lat + "," + lon + ".json";
        Uri uri = new Uri(url);
        WebRequest webRequest = WebRequest.Create(uri);
        WebResponse response = webRequest.GetResponse();
        StreamReader streamReader = new StreamReader(response.GetResponseStream());
        String responseData = streamReader.ReadToEnd();

        var container = JsonConvert.DeserializeObject<HistoryResponseContainer>(responseData);

        foreach (var pws in container.location.nearby_weather_stations.pws.station) {
            CurrentData.Write (pws.id + " " + pws.lat + " " + pws.lon);
        }

        foreach (var pws in container.location.nearby_weather_stations.pws.station) {
            StationIDList.Add(pws.id);
        }

        return (StationIDList);

我有另一種方法，其中相同的方法工作正常。

public void GetFiveMinuteData(List<String> StationIDList, String Date, String Filename) {

        //specify file name, instructions, and priveleges
        FileStream CurrentDataFile = new FileStream (Filename, FileMode.OpenOrCreate, FileAccess.Write);
        //create a new stream to write to the file
        StreamWriter CurrentData = new StreamWriter (CurrentDataFile);

        foreach (String StationID in StationIDList) { 

            string url = @"http://api.wunderground.com/api/" + wundergroundkey + "/history_" + Date + "/q/pws:" + StationID + ".json";
            Uri uri = new Uri (url);
            WebRequest webRequest = WebRequest.Create (uri);
            WebResponse response = webRequest.GetResponse ();
            StreamReader streamReader = new StreamReader (response.GetResponseStream ());
            String responseData = streamReader.ReadToEnd ();

            var container = JsonConvert.DeserializeObject<HistoryResponseContainer> (responseData);

            foreach (var observation in container.history.observations) {

                CurrentData.Write (StationID + " " + Date + " ");
                // This makes easier access to the date. not perfect, but better.
                DateTime date = observation.date.Value;
                DateTime utc = observation.utcdate.Value;

                // whatever you want to do with each observation
                if (date.Minute == 0 || date.Minute % 5 == 0) {
                    CurrentData.Write (date.Hour + ":" + date.Minute + " " + observation.wdird + " " + observation.wspdi);
                }//end if

                CurrentData.Write ("\n");
            } //End foreach observation

        } //end foreach station

        Console.WriteLine ("CurrentDataFile complete!");

Answer 1

這些行；

//specify file name, instructions, and priveleges
        FileStream CurrentDataFile = new FileStream (filename, FileMode.OpenOrCreate, FileAccess.Write);
        //create a new stream to write to the file
        StreamWriter CurrentData = new StreamWriter (CurrentDataFile);

沒有按照您的期望去做。 您永遠不會將任何內容寫入文件，也永遠不會刷新流。 除此之外，您的代碼缺少適當的using語句。 如果您想繼續使用流閱讀器/寫入類，請查看它們在msdn上的文檔，它們提供了很好的示例，您根本無需關注。

另一種選擇是簡化您的問題並使用以下內容；

 File.WriteAllText(aStringWithDataThatIwantInTheFile);

 string fileContents = File.ReadAllText(@"C:\thefilepath.txt");

 string[] fileLines = File.ReadAllLines(AStringWithMyFilePath);

 File.WriteAllLines(AStringArrayGoesHere);

抱歉，我將使用您當前的代碼，但是沒有太多意義，因為我將不得不完全重寫該方法，並且我不知道您實際上希望將什么數據寫入文件，因為您從未真正告訴StreamWriter您分配寫入的數據任何事情，您只需分配它，然后繼續做其他事情。