（系列六）.net8 全局异常捕获机制

 /// <summary>
 /// 接口返回实体模型
 /// </summary>
 public class ReceiveStatus
 {
     /// <summary>
     /// 编码
     /// </summary>
     public CodeStatuEnum code { get; set; }

     /// <summary>
     /// 信息
     /// </summary>
     public string msg { get; set; }

     /// <summary>
     /// 是否成功
     /// </summary>
     public bool success { get; set; }

     /// <summary>
     /// 构造函数
     /// </summary>
     public ReceiveStatus()
     {
         code = CodeStatuEnum.Successful;
         success = true;
         msg = "操作成功";
     }
 }
 /// <summary>
 /// 接口返回结果集
 /// </summary>
 /// <typeparam name="T"></typeparam>
 public class ReceiveStatus<T> : ReceiveStatus
 {
     /// <summary>
     /// 数据
     /// </summary>
     public List<T> data { get; set; }

     /// <summary>
     /// 总数量
     /// </summary>
     public int total { get; set; }
 }

 /// <summary>
 /// 代码状态枚举
 /// </summary>
 public enum CodeStatuEnum
 {
     /// <summary>
     /// 操作成功
     /// </summary>
     Successful = 200,

     /// <summary>
     ///  警告
     /// </summary>
     Warning = 99991,

     /// <summary>
     /// 操作引发错误
     /// </summary>
     Error = 99992
 }

/// <summary>
/// 异常帮助类
/// </summary>
public class ExceptionHelper
{
    /// <summary>
    /// 自定义异常(会写入错误日志表)
    /// </summary>
    /// <param name="msg"></param>
    public static void ThrowBusinessException(string msg)
    {
        throw new Exception(msg);
    }

    /// <summary>
    /// 自定义业务异常(不会写入错误日志表)
    /// </summary>
    /// <param name="msg">信息信息</param>
    /// <param name="codeStatu">异常状态</param>
    /// <returns>返回结果集</returns>
    public static ReceiveStatus CustomException(string msg, CodeStatuEnum codeStatu = CodeStatuEnum.Warning)
    {
        ReceiveStatus receiveStatus = new();
        receiveStatus.code = codeStatu;
        receiveStatus.msg = msg;
        receiveStatus.success = false;
        return receiveStatus;
    }

}

/// <summary>
/// 异常帮助类（返回数据）
/// </summary>
/// <typeparam name="T"></typeparam>
public class ExceptionHelper<T> : ExceptionHelper
{
    /// <summary>
    /// 自定义业务异常(不会写入错误日志表)
    /// </summary>
    /// <param name="msg">信息信息</param>
    /// <param name="codeStatu">异常状态</param>
    /// <returns>返回结果集</returns>
    public static ReceiveStatus<T> CustomExceptionData(string msg, CodeStatuEnum codeStatu = CodeStatuEnum.Warning)
    {
        ReceiveStatus<T> receiveStatus = new();
        receiveStatus.code = codeStatu;
        receiveStatus.msg = msg;
        receiveStatus.success = false;
        receiveStatus.data = new System.Collections.Generic.List<T>();
        return receiveStatus;
    }
}

/// <summary>
/// 全局异常捕获中间件
/// </summary>
public class ExceptionPlugIn : IAsyncExceptionFilter
{
    /// <summary>
    /// 全局异常捕获接口
    /// </summary>
    /// <param name="context"></param>
    /// <returns></returns>
    public Task OnExceptionAsync(ExceptionContext context)
    {
        //异常信息
        Exception ex = context.Exception;

        //异常位置
        var DisplayName = context.ActionDescriptor.DisplayName;

        //异常行号
        int lineNumber = 0;
        const string lineSearch = ":line ";
        var index = ex.StackTrace.LastIndexOf(lineSearch);
        if (index != -1)
        {
            var lineNumberText = ex.StackTrace.Substring(index + lineSearch.Length);
            lineNumber = Convert.ToInt32(lineNumberText.Substring(0, lineNumberText.IndexOf("\r\n")));
        }

        // 如果异常没有被处理则进行处理
        if (context.ExceptionHandled == false)
        {
            string exceptionMsg = "错误位置：" + DisplayName + "\r\n" + "错误行号：" + lineNumber + "\r\n" + "错误信息：" + ex.Message;
            // 定义返回类型
            var result = new ReceiveStatus<string>
            {
                code = CodeStatuEnum.Error,
                msg = "错误信息：" + exceptionMsg,
                success = false,
            };
            context.Result = new ContentResult
            {
                // 返回状态码设置为200，表示
                StatusCode = StatusCodes.Status500InternalServerError,
                // 设置返回格式
                ContentType = "application/json;charset=utf-8",
                Content = JsonConvert.SerializeObject(result)
            };
            //记录日志

        }
        // 设置为true，表示异常已经被处理了
        context.ExceptionHandled = true;
        return Task.CompletedTask;
    }
}

//自定义全局异常处理
builder.Services.AddControllers(a =>
{
    a.Filters.Add(typeof(ExceptionPlugIn));
});