下载c#excel字节数组并将其转换为javascript blob

问题描述 投票:1回答:2

我正在使用POST方法来获取Excel文件的字节数组

c#服务器端实现:

 downloadExcel() {
    ....
    FileResultDto fileResultDto = new FileResultDto
    {
       Data = ExcelHelper.CreateExcelFile(excelFile) //Data contains the byte array
    };

    return new JsonHttpResponseMessage(JsonConvert.SerializeObject(fileResultDto));
}

CreateExcelFile():

public byte[] CreateExcelFile(ExcelFile excelFile)
    {
        try
        {
            #region Validation

            if (excelFile == null)
            {
                throw new ArgumentNullException(nameof(excelFile));
            }

            #endregion

            byte[] bytes;

            using (ExcelPackage excelPackage = new ExcelPackage())
            {
                for (int i = 1; i <= excelFile.Worksheets.Count; i++)
                {
                    Worksheet worksheet = excelFile.Worksheets[i - 1];

                    excelPackage.Workbook.Worksheets.Add(worksheet.Name);

                    ExcelWorksheet currentExcelWorksheet = excelPackage.Workbook.Worksheets[i];

                    if (excelFile.HasLogoTemplate)
                    {
                        byte[] imageBytes = Convert.FromBase64String(LogoBase64);

                        Image image;
                        using (MemoryStream ms = new MemoryStream(imageBytes, 0, imageBytes.Length))
                        {
                            image = Image.FromStream(ms, true);
                        }

                        ExcelPicture picture = currentExcelWorksheet.Drawings.AddPicture("Logo", image);

                        picture.SetPosition(0, 4, 0, 10);

                        currentExcelWorksheet.Row(1).Height = 50;
                    }

                    SetColumnsWidths(currentExcelWorksheet, worksheet);

                    WriteHeaderRow(currentExcelWorksheet, worksheet.HeaderRow);

                    WriteCells(currentExcelWorksheet, worksheet.Cells);
                }

                #region Set Excel Stream

                bytes = excelPackage.GetAsByteArray();

                #endregion
            }

            return bytes;
        }
        catch (Exception exception)
        {
            throw new Exception("There was an error on excel export. Exception: ", exception);
        }
    }

前端实现:

public downloadExcel(): void {

    this.myRepository.downloadExcel(this.postData).then(result => {
        var byteArray = new Uint8Array(result.data.data);

        var a = window.document.createElement('a');
        a.href = window.URL.createObjectURL(new Blob([byteArray], { type: "application/octet-stream" }));

        a.download = "test.xlsx";

        document.body.appendChild(a);
        a.click();
        document.body.removeChild(a);
    }, error => {
        console.log(error);
    });
}

显然,创建的Blob文件似乎已损坏。有什么建议可以解决问题吗?

javascript c# excel
2个回答
0
投票
在Angular中也是如此。这可能对您有帮助

downloadExcel(){ this.downloadAttachment(filename).subscribe(res => { let Res=res; const downloadedFile = new Blob([Res], { type: Res.type });             const a = document.createElement('a');             a.setAttribute('style', 'display:none;');             document.body.appendChild(a);             a.download = attachment.filename;             a.href = URL.createObjectURL(downloadedFile);             a.target = '_blank';             a.click();             document.body.removeChild(a); }, err=>{ throw err; }) } downloadAttachment(filename){ this.httpOptions = { reportProgress: true, responseType: "blob" }; return this.http.get(API_URL, this.httpOptions).pipe( map(response => response), catchError(this.handleError<any>(isShowError)), finalize(() => { }) ); }

C#代码

var res=DownloadAttachment(filename); if (res == null) return Content("filename not present"); return File(res, Utility.GetContentType(filename), filename);


0
投票
最后,使用'arraybuffer'作为http请求的响应类型解决了问题。

let requestConfiguration: ng.IRequestConfig = { cache: ..., data: ..., headers: ..., method: ..., url: ..., responseType: 'arraybuffer' }; let promise: ng.IPromise<any> = this.$http(requestConfiguration);

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