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

如果您尝试在订阅内部调用新方法,效果会更好

this._reportService.getReport()
    .subscribe((data: any) => {
        this.downloadFile(data);
    },
        (error: any) => сonsole.log(error),
        () => console.log('Complete')
    );

在downloadFile(data)函数中,我们需要创建block, link, href和文件名

downloadFile(data: any, type: number, name: string) {
    const blob = new Blob([data], {type: 'text/csv'});
    const dataURL = window.URL.createObjectURL(blob);

    // IE doesn't allow using a blob object directly as link href
    // instead it is necessary to use msSaveOrOpenBlob
    if (window.navigator && window.navigator.msSaveOrOpenBlob) {
      window.navigator.msSaveOrOpenBlob(blob);
      return;
    }

    const link = document.createElement('a');
    link.href = dataURL;
    link.download = 'export file.csv';
    link.click();

    setTimeout(() => {

      // For Firefox it is necessary to delay revoking the ObjectURL
      window.URL.revokeObjectURL(dataURL);
      }, 100);
    }
}

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

这是为那些寻找如何使用HttpClient和文件保存器的人准备的:

点击安装

NPM安装文件保护程序 NPM install @types/file-saver

API服务类:

export() {
    return this.http.get(this.download_endpoint, 
        {responseType: 'blob'});
}

组件:

import { saveAs } from 'file-saver';
exportPdf() {
    this.api_service.export().subscribe(data => saveAs(data, `pdf report.pdf`));
}

我找到的答案要么是在Angular 13.1上无法运行,要么是不必要的复杂(就像被接受的例子一样),而且没有解释为什么这是必要的。 对于像Angular这样不断变化的生态系统来说,要求附加版本号是非常有用的。

用户@Aleksandar Angelov提供的迷你代码片段绕过了会话系统,因此需要进行不必要的授权。

根据他的回答,我得出了以下代码:

  downloadConfiguration(url: string, filename: string) {
    this.http.get(url, {responseType: 'blob'})
    .subscribe(data => {
      // console.log("data", data);
      var url = window.URL.createObjectURL(data);
      let downloadLink = document.createElement('a');
      downloadLink.href = url
      downloadLink.setAttribute('download', filename);
      downloadLink.click();
    });
  }

下载和显示PDF文件,一个非常相似的代码剪辑如下:

  private downloadFile(data: Response): void {
    let blob = new Blob([data.blob()], { type: "application/pdf" });
    let url = window.URL.createObjectURL(blob);
    window.open(url);
  }

  public showFile(fileEndpointPath: string): void {
    let reqOpt: RequestOptions = this.getAcmOptions();  //  getAcmOptions is our helper method. Change this line according to request headers you need.
    reqOpt.responseType = ResponseContentType.Blob;
    this.http
      .get(fileEndpointPath, reqOpt)
      .subscribe(
        data => this.downloadFile(data),
        error => alert("Error downloading file!"),
        () => console.log("OK!")
      );
  }

如果您尝试在订阅内部调用新方法,效果会更好

this._reportService.getReport()
    .subscribe((data: any) => {
        this.downloadFile(data);
    },
        (error: any) => сonsole.log(error),
        () => console.log('Complete')
    );

在downloadFile(data)函数中,我们需要创建block, link, href和文件名

downloadFile(data: any, type: number, name: string) {
    const blob = new Blob([data], {type: 'text/csv'});
    const dataURL = window.URL.createObjectURL(blob);

    // IE doesn't allow using a blob object directly as link href
    // instead it is necessary to use msSaveOrOpenBlob
    if (window.navigator && window.navigator.msSaveOrOpenBlob) {
      window.navigator.msSaveOrOpenBlob(blob);
      return;
    }

    const link = document.createElement('a');
    link.href = dataURL;
    link.download = 'export file.csv';
    link.click();

    setTimeout(() => {

      // For Firefox it is necessary to delay revoking the ObjectURL
      window.URL.revokeObjectURL(dataURL);
      }, 100);
    }
}