如何在ajax中下载每种类型的文件？

Question

我需要下载 js 和 c# 类型的每个文件。

这是我的api代码：

[HttpPost]

public HttpResponseMessage GetFile(DownloadInput input)
{
    HttpResponseMessage response = Request.CreateResponse(HttpStatusCode.OK);
    var fileNm = input.FileName;
    string filePath = (@"C:\Uploads\" + input.ID + @"\" + fileNm);

    if (!File.Exists(filePath))
    {
        response.StatusCode = HttpStatusCode.NotFound;
        response.ReasonPhrase = string.Format("File not found: {0} .", fileNm);
        throw new HttpResponseException(response);
    }
    byte[] bytes = File.ReadAllBytes(filePath);
    response.Content = new ByteArrayContent(bytes);
    response.Content.Headers.ContentLength = bytes.LongLength;
    response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
    response.Content.Headers.ContentDisposition.FileName = fileNm;
    response.Content.Headers.ContentType = new MediaTypeHeaderValue(MimeMapping.GetMimeMapping(filePath));
    return response;
}

我认为这部分代码下载了每个文件，但只适用于 .txt 类型的文件，我认为 blob 类型是错误的，但我是新主题，我尝试了每个代码，

这是我的js代码：

function FileDown(response, name) {
    let blob = new Blob([response], { type: "application/octet-stream" });
    let link = document.createElement('a');
    link.href = window.URL.createObjectURL(blob);
    link.download = name;
    link.click();
}

Answer 1

您可以尝试以下方法，我已经成功使用过很多次了。

首先，您需要确保保存的数据正确无误。 由于您需要 mimetype 才能成功下载文件而不会出现复杂情况。

这是 C#（PS：您可以创建端点 HttpGet，而不是 HttpPost。）

[HttpGet]
[Route("YourController/{fileName}")]
public HttpResponseMessage Download(string fileName) //Parameter is yours
{
    string filePath = (@"C:\Uploads\" + input.ID + @"\" + fileName);

    if (!File.Exists(filePath))
    {
        response.StatusCode = HttpStatusCode.NotFound;
        response.ReasonPhrase = string.Format("File not found: {0} .", fileNm);
        throw new HttpResponseException(response);
    }
    byte[] bytes = File.ReadAllBytes(filePath);

    using (var ms = new MemoryStream(bytes))
    {
        var result = new HttpResponseMessage(HttpStatusCode.OK)
        {
            Content = new ByteArrayContent(ms.ToArray())
        };

        result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
        {
            FileName = fileName //String value of the file name.
        };

        string mimeType = MimeMapping.GetMimeMapping(fileName); //I've found that this does not always work. Go here for a better answer: https://stackoverflow.com/questions/1029740/get-mime-type-from-filename-extension
        result.Content.Headers.ContentType = new MediaTypeHeaderValue(mimeType); //The mime type retrieved from the 

        return result;
    }
}

在 javascript 中，您可以使用： window.open('yourApiURL/YourController/FileName');