前端：

引用signalr三方包

backend/IM_API/Hubs/ChatHub.cs

@@ -42,7 +42,7 @@ namespace IM_API.Hubs
             }
             var userIdStr = Context.User.FindFirstValue(ClaimTypes.NameIdentifier);
             await _messageService.SendPrivateMessageAsync(int.Parse(userIdStr),dto.ReceiverId,dto);
-            await Clients.Users(dto.ReceiverId.ToString()).SendAsync("ReceiveMessage", userIdStr, dto.Content);
+            await Clients.Users(dto.ReceiverId.ToString()).SendAsync("ReceiveMessage", dto);
             return;
         }
     }

backend/IM_API/Program.cs

@@ -44,7 +44,13 @@ namespace IM_API
                     policy.AllowAnyHeader()
                     .AllowAnyMethod()
                     .AllowAnyHeader()
-                    .AllowAnyOrigin();
+                    .AllowCredentials()
+                    .SetIsOriginAllowed(origin =>
+                    {
+                        // 允许所有来自本地或特定网段的请求
+                        var host = new Uri(origin).Host;
+                        return host == "localhost" || host.StartsWith("192.168.");
+                    });
                 });
             });
             //凭证处理
@@ -86,11 +92,7 @@ namespace IM_API
                                 context.Token = accessToken;
                             }
                             return Task.CompletedTask;
-                        }
-                    };
-
-                    options.Events = new JwtBearerEvents
-                    {
+                        },
                         OnAuthenticationFailed = context =>
                         {
                             Console.WriteLine("Authentication failed: " + context.Exception.Message);