在Angular中下载文件时无法获取进度和文件 [英] Trouble getting progress and file when downloading a file in Angular

问题描述

我有一个Angular应用程序，我只想下载一个文件.

I have an Angular application where I just want to download a file.

到目前为止，这是我的代码:

Up until now, this was my code:

this.fileNavigationService.downloadFile(element).subscribe(result => {
    this.generateDownload(result);
});

我的服务

downloadFile(file: FileElement) {
    return this.http.get(this.apiUrl + '/downloadFile', { params: file.name, responseType: 'blob' });
}

现在，我想在下载文件时显示进度.在网上查找后，我发现了一些非常有用的东西.我的服务现在看起来像这样:

Now, I wanted to show the progression when I download a file. After looking up online, I came across something quite useful. My service now looks like this:

downloadFile(file: FileElement) {
    const req = new HttpRequest('GET', '/downloadFile?path=' + file.name, {
      reportProgress: true,
    });

    return this.http.request(req).subscribe(event => {
      if (event.type === HttpEventType.DownloadProgress) {
        const percentDone = Math.round(100 * event.loaded / event.total);
        console.log(`File is ${percentDone}% downloaded.`);
      } else if (event instanceof HttpResponse) {
        console.log('File is completely downloaded!');
      }
    });
}

我可以在控制台中清楚地看到进度，但是，现在有两个问题:

I can clearly see in my console the progress, however, I have now 2 problems:

• 即使下载似乎已达到100％，我的代码也永远不会进入最后一个 if
• 我的组件中的代码显然在订阅方法上被破坏了

• My code never goes into the last if even though the download appears to reach 100%
• The code in my component is obviously broken on the subscribe method

预订"类型上不存在预订"属性.

Property 'subscribe' does not exist on type 'Subscription'.

但是我似乎找不到找到使之可行的方法，因此我可以获取进度和结果文件.

But I can't seem to find a way to make this works so I can get the progression and my result file.

您有什么想法或例子可以帮助我吗?谢谢.

Do you have any idea or examples to help me on this? Thanks.

推荐答案

经过研究，终于有了此答案，我终于设法解决了我的问题.

现在这是我的服务代码:

This is now my service code:

downloadFile(file: FileElement) {
  return this.http.get(
    this.apiUrl + '/downloadFile', 
    { 
        params: file.name, 
        responseType: 'blob',
        reportProgress: true,
        observe: 'events', 
        headers: new HttpHeaders({ 'Content-Type': 'application/json' }) 
    }
  );
}

在我的组件中:

this.fileNavigationService.downloadFile(element).subscribe(result => {
    if (result.type === HttpEventType.DownloadProgress) {
      const percentDone = Math.round(100 * result.loaded / result.total);
      console.log(percentDone);
    }
    if (result.type === HttpEventType.Response) {
      this.generateDownload(result.body);
    }
});

这篇关于在Angular中下载文件时无法获取进度和文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！