c# Signalr报错:消息大小超出了最大限制32kB。消息大小可在AddHubOptions中配置。

夏霞2026-03-26 8:42

csharp 复制代码

The maximum message size of 32kB was exceeded. The message size can be configured in AddHubOptions.

报错位置是：

csharp 复制代码

  public override async Task OnDisconnectedAsync(Exception? exception)
  {
      if (exception != null) {
          //记录错误日志
          //The maximum message size of 32kB was exceeded. The message size can be configured in AddHubOptions.
      }
     
      await base.OnDisconnectedAsync(exception);
  }

参考微软官方文档：在这里插入图片描述

https://learn.microsoft.com/zh-cn/aspnet/core/signalr/hubs?view=aspnetcore-10.0

解决办法：

在Program.cs 文件中增加： options.MaximumReceiveMessageSize = 2097152;将限制改为2M

参考微软官方文档：https://learn.microsoft.com/zh-cn/aspnet/core/signalr/configuration?view=aspnetcore-10.0&tabs=dotnet

csharp 复制代码

builder.Services.AddSignalR().AddHubOptions<ChatHub>(options =>
{
    options.EnableDetailedErrors = true;
    options.MaximumReceiveMessageSize = 2097152;//2 * 1024 * 1024;  2MB  限制改为2M
}) .AddJsonProtocol(options =>
    {
        // 禁用驼峰命名法，保留原始属性名
        options.PayloadSerializerOptions.PropertyNamingPolicy = null;
        // 允许未定义属性（避免旧客户端缺失字段时报错）
        options.PayloadSerializerOptions.WriteIndented = false;
        options.PayloadSerializerOptions.DefaultIgnoreCondition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingDefault;
       
    });