我有一个WebApi / MVC应用程序,我正在为它开发一个angular2客户端(以取代MVC)。我在理解Angular如何保存文件时遇到了一些麻烦。

请求是可以的(与MVC一起工作很好,我们可以记录接收到的数据),但我不知道如何保存下载的数据(我主要遵循与本文相同的逻辑)。我确信这是愚蠢的简单,但到目前为止,我根本没有领会它。

组件函数的代码如下。我尝试了不同的替代方案,blob方式应该是我所理解的方式,但URL中没有createObjectURL函数。我甚至不能在窗口中找到URL的定义,但显然它存在。如果我使用FileSaver.js模块,我得到同样的错误。所以我猜这是最近改变的或者还没有实现的东西。我如何触发文件保存在A2?

downloadfile(type: string){

    let thefile = {};
    this.pservice.downloadfile(this.rundata.name, type)
        .subscribe(data => thefile = new Blob([data], { type: "application/octet-stream" }), //console.log(data),
                    error => console.log("Error downloading the file."),
                    () => console.log('Completed file download.'));

    let url = window.URL.createObjectURL(thefile);
    window.open(url);
}

为了完整起见,获取数据的服务如下所示,但它所做的唯一一件事是发出请求并在没有映射的情况下传递数据:

downloadfile(runname: string, type: string){
   return this.authHttp.get( this.files_api + this.title +"/"+ runname + "/?file="+ type)
            .catch(this.logAndPassOn);
}

当前回答

 let headers = new Headers({
                'Content-Type': 'application/json',
                'MyApp-Application': 'AppName',
                'Accept': 'application/vnd.ms-excel'
            });
            let options = new RequestOptions({
                headers: headers,
                responseType: ResponseContentType.Blob
            });


this.http.post(this.urlName + '/services/exportNewUpc', localStorageValue, options)
                .subscribe(data => {
                    if (navigator.appVersion.toString().indexOf('.NET') > 0)
                    window.navigator.msSaveBlob(data.blob(), "Export_NewUPC-Items_" + this.selectedcategory + "_" + this.retailname +"_Report_"+this.myDate+".xlsx");

                    else {
                        var a = document.createElement("a");
                        a.href = URL.createObjectURL(data.blob());
                        a.download = "Export_NewUPC-Items_" + this.selectedcategory + "_" + this.retailname +"_Report_"+this.myDate+ ".xlsx";
                        a.click();
                    }
                    this.ui_loader = false;
                    this.selectedexport = 0;
                }, error => {
                    console.log(error.json());
                    this.ui_loader = false;
                    document.getElementById("exceptionerror").click();
                });

其他回答

我分享了帮助我的解决方案(任何改进都非常感谢)

关于你的服务“pservice”:

getMyFileFromBackend(typeName: string): Observable<any>{
    let param = new URLSearchParams();
    param.set('type', typeName);
    // setting 'responseType: 2' tells angular that you are loading an arraybuffer
    return this.http.get(http://MYSITE/API/FILEIMPORT, {search: params, responseType: 2})
            .map(res => res.text())
            .catch((error:any) => Observable.throw(error || 'Server error'));
}

组成部分:

downloadfile(type: string){
   this.pservice.getMyFileFromBackend(typename).subscribe(
                    res => this.extractData(res),
                    (error:any) => Observable.throw(error || 'Server error')
                );
}

extractData(res: string){
    // transforme response to blob
    let myBlob: Blob = new Blob([res], {type: 'application/vnd.oasis.opendocument.spreadsheet'}); // replace the type by whatever type is your response

    var fileURL = URL.createObjectURL(myBlob);
    // Cross your fingers at this point and pray whatever you're used to pray
    window.open(fileURL);
}

在组件部分,无需订阅响应即可调用服务。订阅 有关openOffice mime类型的完整列表,请参见:http://www.openoffice.org/framework/documentation/mimetypes/mimetypes.html

定位12 +最高一个网站

您可以从服务器返回一个Blob对象,并创建一个锚标记,并将href属性设置为从Blob创建的对象URL。现在点击锚点将下载文件。您也可以设置文件名。

downloadFile(path: string): Observable<any> {
        return this._httpClient.post(`${environment.ApiRoot}/accountVerification/downloadFile`, { path: path }, {
            observe: 'response',
            responseType: 'blob'
        });
    }

saveFile(path: string, fileName: string): void {
            this._accountApprovalsService.downloadFile(path).pipe(
                take(1)
            ).subscribe((resp) => {
                let downloadLink = document.createElement('a');
                downloadLink.href = window.URL.createObjectURL(resp.body);
                downloadLink.setAttribute('download', fileName);
                document.body.appendChild(downloadLink);
                downloadLink.click();
                downloadLink.remove();
            });
            
        }

后端

[HttpPost]
[Authorize(Roles = "SystemAdmin, SystemUser")]
public async Task<IActionResult> DownloadFile(FilePath model)
{
    if (ModelState.IsValid)
    {
        try
        {
            var fileName = System.IO.Path.GetFileName(model.Path);
            var content = await System.IO.File.ReadAllBytesAsync(model.Path);
            new FileExtensionContentTypeProvider()
                .TryGetContentType(fileName, out string contentType);
            return File(content, contentType, fileName);
        }
        catch
        {
            return BadRequest();
        }
    }

    return BadRequest();

}

问题是可观察对象运行在另一个上下文中,所以当你尝试创建URL var时,你有一个空对象,而不是你想要的blob。

解决这个问题的众多方法之一如下:

this._reportService.getReport().subscribe(data => this.downloadFile(data)),//console.log(data),
                 error => console.log('Error downloading the file.'),
                 () => console.info('OK');

当请求准备好时,它将调用函数"downloadFile",定义如下:

downloadFile(data: Response) {
  const blob = new Blob([data], { type: 'text/csv' });
  const url= window.URL.createObjectURL(blob);
  window.open(url);
}

这个blob已经被完美地创建了,所以URL变量,如果没有打开新的窗口,请检查你已经导入'rxjs/Rx';

import 'rxjs/Rx' ;

我希望这能帮助到你。

这个怎么样?

this.http.get(targetUrl,{responseType:ResponseContentType.Blob})
        .catch((err)=>{return [do yourself]})
        .subscribe((res:Response)=>{
          var a = document.createElement("a");
          a.href = URL.createObjectURL(res.blob());
          a.download = fileName;
          // start download
          a.click();
        })

我可以接受。 不需要额外包装。

对于那些使用Redux模式

我在文件保存器中添加了@Hector Cuevas的名字,在他的回答中。使用Angular2 v. 2.3.1,我不需要添加@types/file-saver。

以PDF格式下载日志为例。

日记账操作

public static DOWNLOAD_JOURNALS = '[Journals] Download as PDF';
public downloadJournals(referenceId: string): Action {
 return {
   type: JournalActions.DOWNLOAD_JOURNALS,
   payload: { referenceId: referenceId }
 };
}

public static DOWNLOAD_JOURNALS_SUCCESS = '[Journals] Download as PDF Success';
public downloadJournalsSuccess(blob: Blob): Action {
 return {
   type: JournalActions.DOWNLOAD_JOURNALS_SUCCESS,
   payload: { blob: blob }
 };
}

期刊效应

@Effect() download$ = this.actions$
    .ofType(JournalActions.DOWNLOAD_JOURNALS)
    .switchMap(({payload}) =>
        this._journalApiService.downloadJournal(payload.referenceId)
        .map((blob) => this._actions.downloadJournalsSuccess(blob))
        .catch((err) => handleError(err, this._actions.downloadJournalsFail(err)))
    );

@Effect() downloadJournalSuccess$ = this.actions$
    .ofType(JournalActions.DOWNLOAD_JOURNALS_SUCCESS)
    .map(({payload}) => saveBlobAs(payload.blob, 'journal.pdf'))

期刊服务

public downloadJournal(referenceId: string): Observable<any> {
    const url = `${this._config.momentumApi}/api/journals/${referenceId}/download`;
    return this._http.getBlob(url);
}

HTTP服务

public getBlob = (url: string): Observable<any> => {
    return this.request({
        method: RequestMethod.Get,
        url: url,
        responseType: ResponseContentType.Blob
    });
};

轴颈减速器 虽然这只设置了我们应用程序中使用的正确状态,但我仍然想添加它来显示完整的模式。

case JournalActions.DOWNLOAD_JOURNALS: {
  return Object.assign({}, state, <IJournalState>{ downloading: true, hasValidationErrors: false, errors: [] });
}

case JournalActions.DOWNLOAD_JOURNALS_SUCCESS: {
  return Object.assign({}, state, <IJournalState>{ downloading: false, hasValidationErrors: false, errors: [] });
}

我希望这对你有帮助。