使用CSVHelper到输出流的浏览器 [英] Using CSVHelper to output stream to browser

问题描述

我试图用CSVHelper生成CSV文件并将其发送回浏览器，因此用户可以选择一个保存位置和文件名和保存数据。

I'm trying to use CSVHelper to generate a CSV file and send it back to a browser, so the user can select a save location and filename and save the data.

该网站是基于MVC。下面是jQuery的按钮code我使用拨打电话（数据的DTO列表中的一些序列化的Json重新presentation）：

The website is MVC based. Here' the jQuery button code I'm using to make the call (data is some serialised Json representation of a DTO list):

    $.ajax({
        type: "POST",
        url: unity.baseUrl + "common/ExportPayments",
        data: data
    });

下面是控制器code：

Here's the controller code:

    [HttpPost]
    public FileStreamResult ExportPayments()
    {
        MemoryStream ms = new MemoryStream();
        StreamWriter sw = new StreamWriter(ms);
        CsvWriter writer = new CsvWriter(sw);

        List<Payment_dto> pd = _commonService.GetPayments();

        foreach (var record in pd)
        {
            writer.WriteRecord(record);
        }
        sw.Flush();

        return new FileStreamResult(ms, "text/csv");
    }

这似乎达到precisely什么 - 调用方法步骤到code正确的位，但响应是空的，更何况是给用户提供一个文件对话框来保存数据。我已经通过这个code加大，而且带回的数据服务，将其写入，并抛出任何错误。所以我在做什么错了？

Which seems to achieve precisely nothing - invoking the method steps into the correct bit of code but the response is empty, let alone offering the user a file dialog to save the data. I've stepped through this code, and it brings back data from the service, writes it, and throws no errors. So what am I doing wrong?

编辑：回到这...

return File(ms.GetBuffer(), "text/csv", "export.csv");

...给我一个答复，其中包括了我期待的CSV格式的数据。但浏览器似乎仍然不知道该怎么做了它 - 没有下载选项提供给用户

... gives me a response, consisting of the csv-formatted data that I'm expecting. But the browser still doesn't seem to know what to do with it - no download option is offered to the user.

推荐答案

尝试下面code：

    public FileStreamResult  ExportPayments()
    {
        var result = WriteCsvToMemory(_commonService.GetPayments()()); 
        var memoryStream = new MemoryStream(result);
        return new FileStreamResult(memoryStream, "text/csv") { FileDownloadName = "export.csv" };
    }


    public byte[] WriteCsvToMemory(IEnumerable<Payment_dto> records)
    {
        using (var memoryStream = new MemoryStream())
        using (var streamWriter = new StreamWriter(memoryStream))
        using (var csvWriter = new CsvWriter(streamWriter))
        {
            csvWriter.WriteRecords(records);
            streamWriter.Flush();
            return memoryStream.ToArray();
        }
    }

更新

下面是如何通过一个复杂类型模型是使用 GET HTTP方法的操作方法。我不preFER这种方法，它只是给你一个想法有实现这一目标的方法。

Below is how to pass a complex type model to an action method which is using GET HTTP method. I don't prefer this approach, it just gives you an idea there is an approach to achieve this.

型号

    public class Data
    {
        public int Id { get; set; }
        public string Value { get; set; }

        public static string Serialize(Data data)
        {
            var serializer = new JavaScriptSerializer();
            return serializer.Serialize(data);
        }
        public static Data Deserialize(string data)
        {
            var serializer = new JavaScriptSerializer();
            return serializer.Deserialize<Data>(data);
        }
    }

动作：

    [HttpGet]
    public FileStreamResult ExportPayments(string model) 
    {
        //Deserialize model here 
        var result = WriteCsvToMemory(GetPayments()); 
        var memoryStream = new MemoryStream(result);
        return new FileStreamResult(memoryStream, "text/csv") { FileDownloadName = "export.csv" };
    }

查看：

@{
    var data = new Data()
    {
        Id = 1,
        Value = "This is test"
    };
}
@Html.ActionLink("Export", "ExportPayments", new { model = Data.Serialize(data) })

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