//可以訪問wwwroot下的靜態(tài)文件
app.UseStaticFiles();
//可以訪問其他目錄下的文件
app.UseStaticFiles(new StaticFileOptions
{
     FileProvider = new PhysicalFileProvider(Path.Combine(env.ContentRootPath, "MyStaticFiles")),
     RequestPath = "/StaticFiles",
     OnPrepareResponse=ctx=>
     {
        //還可以添加額外響應頭
        ctx.Context.Response.Headers.Append("Cache-control",$"public, max-age=604800");
     }
});

 string path = AppContext.BaseDirectory;
 path = Path.Combine(path, "UploadFiles");
 //通過url訪問文件
 app.UseStaticFiles(new StaticFileOptions()//自定義自己的文件路徑
 {
     RequestPath = new PathString("/UploadFiles"),//對外的訪問路徑
     FileProvider = new PhysicalFileProvider(path)//指定實際物理路徑
 });