TXT file can be opened after the download
Images and PDF, etc all can't,

Vue. Js code

 
OnDownload (docId, docName) {
Return new Promise (()=& gt; {
This. DeviceTechDocSvc. DownloadDeviceTechDoc (docId). Then ((resp)=& gt; {
If (resp. Status==200) {
Let the blob=new blob ([resp. Data], {
Type: resp. Headers [" the content-type "],//PDF 'application/octet - stream; Charset=utf-8 '
}); 
If (window. The navigator & amp; & Window. The navigator. MsSaveOrOpenBlob) {
//compatible with IE 
Window. The navigator. MsSaveOrOpenBlob (blob, docName);//you can customize the file name and suffix 
} else {
//compatible with Google and fireFox 
Var a=document. The createElement method (" a "); 
Document. The body. The appendChild (a); 
A.s tyle="display: none;" 
Var url=window. Url. CreateObjectURL (blob);//create the url 
A.h ref=https://bbs.csdn.net/topics/url; 
A. d. ownload=docName; 
A.c lick (); 
A.r emove (); 
Window. URL. RevokeObjectURL (URL);//release the url 
} 
} 
}); 
}); 
}, 

The back-end code

///& lt; summary> 
///document download 
///& lt;/summary> 
///& lt; Param name="docId" & gt;  
///& lt; Returns>  
[HttpPost (" {docId} ")] 
Public async Task The Download (Guid docId) 
{
Try 
{
The dynamic model=new ExpandoObject (); 
Model. The DocId=DocId; 
Var entity=this. Logic. Get (model); 
If (entity!=null) 
{
//file real address 
The string fileName=${webHostEnvironment. ContentRootPath} \ \ "uploadDeviceTechDocs \ \ {entity. DeviceId} \ \ {entity. DocUri}"; 
The FileInfo the FileInfo=new the FileInfo (fileName); 
If (the fileInfo. The Exists) 
{
FileStream FileStream=the fileInfo. OpenRead (); 
Return new FileStreamResult (fileStream, entity. MimeType); 
} 
} 
return null; 
} 
The catch (BusinessLogicLayerException ex) 
{
Throw new Exception (ex. Message); 
} 
}