我有一个使用Angular 4和Web API的应用程序,我正在尝试使用Web API和TypeScript Blob下载文件。以下是两者的代码示例。
当我单击下载按钮时,会向Web API发送一个POST请求,该请求响应发送文件流,TypeScript将此流转换为图像。但是,当我打开此图像时,它显示以下错误 - “我们无法打开此文件”。
代码 -: Web API
Angular 组件.ts -
代码 -: Web API
public HttpResponseMessage Download()
{
string strFileUrl = "some absolute path";
if (strFileUrl != "")
{
FileInfo file = new FileInfo(strFileUrl);
HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
var stream = new FileStream(file.FullName, FileMode.Open);
response.Content = new StreamContent(stream);
// response.Content = new ByteArrayContent(CommonUtil.FileToByteArray(file.FullName));
response.Content.Headers.ContentType = new MediaTypeHeaderValue(CommonUtil.GetContentType(file.Extension.ToLower()));
response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment") {
FileName = file.Name
};
response.Content.Headers.ContentDisposition.FileName = file.Name;
response.Content.Headers.ContentLength = file.Length;
response.Headers.Add("fileName", file.Name);
return response;
}
return new HttpResponseMessage(HttpStatusCode.NotFound);
}
Angular 组件.ts -
private OnImageDownloadClick()
{
this.uploadServiceRef.DownloadFile(path).subscribe(x => {
// method 1
let head = x.headers.get("Content-Type");
let fileName = x.headers.get("fileName");
this.fileSaverServiceRef.save(x, fileName, head);
OR
// method 2
let head = x.headers.get("Content-Type");
var blob = new Blob([x.arrayBuffer], { type: head });
var fileURL = URL.createObjectURL(blob);
window.open(fileURL);
},
error => console.log(error));
}
Service.ts-
public DownloadFile(path): Observable<any> {
let obj: any = {
path: path
}
this.headers = new Headers();
this.headers.append('Content-Type', 'application/json');
this.headers.append('responseType', ResponseContentType.Blob);
return this.http.request(DOWNLOAD_DOCUMENT_URL, RequestMethod.Post, this.headers, obj)
.map((x) => {
return x;
});
}