关于.NET异常处理的思考总结

2019-05-26 01:05:18王振洲

 (2).验证异常:

  /// <summary>
  /// 检查字符串是空的或空的,并抛出一个异常
  /// </summary>
  /// <param name="val">值测试</param>
  /// <param name="paramName">参数检查名称</param>
  public static void CheckNullOrEmpty(string val, string paramName)
  {
   if (string.IsNullOrEmpty(val))
    throw new ArgumentNullException(paramName, "Value can't be null or empty");
  }

  /// <summary>
  /// 请检查参数不是空的或空的,并抛出异常
  /// </summary>
  /// <param name="param">检查值</param>
  /// <param name="paramName">参数名称</param>
  public static void CheckNullParam(string param, string paramName)
  {
   if (string.IsNullOrEmpty(param))
    throw new ArgumentNullException(paramName, paramName + " can't be neither null nor empty");
  }

  /// <summary>
  /// 检查参数不是无效,并抛出一个异常
  /// </summary>
  /// <param name="param">检查值</param>
  /// <param name="paramName">参数名称</param>
  public static void CheckNullParam(object param, string paramName)
  {
   if (param == null)
    throw new ArgumentNullException(paramName, paramName + " can't be null");
  }

  /// <summary>
  /// 请检查参数1不同于参数2
  /// </summary>
  /// <param name="param1">值1测试</param>
  /// <param name="param1Name">name of value 1</param>
  /// <param name="param2">value 2 to test</param>
  /// <param name="param2Name">name of vlaue 2</param>
  public static void CheckDifferentsParams(object param1, string param1Name, object param2, string param2Name)
  {
   if (param1 == param2) {
    throw new ArgumentException(param1Name + " can't be the same as " + param2Name,
     param1Name + " and " + param2Name);
   }
  }

  /// <summary>
  /// 检查一个整数值是正的(0或更大)
  /// </summary>
  /// <param name="val">整数测试</param>
  public static void PositiveValue(int val)
  {
   if (val < 0)
    throw new ArgumentException("The value must be greater than or equal to 0.");
  }

(3).Try-Catch扩展操作:

  /// <summary>
  ///  对某对象执行指定功能与后续功能,并处理异常情况
  /// </summary>
  /// <typeparam name="T">对象类型</typeparam>
  /// <param name="source">值</param>
  /// <param name="action">要对值执行的主功能代码</param>
  /// <param name="failureAction">catch中的功能代码</param>
  /// <param name="successAction">主功能代码成功后执行的功能代码</param>
  /// <returns>主功能代码是否顺利执行</returns>
  public static bool TryCatch<T>(this T source, Action<T> action, Action<Exception> failureAction,
   Action<T> successAction) where T : class
  {
   bool result;
   try
   {
    action(source);
    successAction(source);
    result = true;
   }
   catch (Exception obj)
   {
    failureAction(obj);
    result = false;
   }
   return result;
  }

  /// <summary>
  ///  对某对象执行指定功能,并处理异常情况
  /// </summary>
  /// <typeparam name="T">对象类型</typeparam>
  /// <param name="source">值</param>
  /// <param name="action">要对值执行的主功能代码</param>
  /// <param name="failureAction">catch中的功能代码</param>
  /// <returns>主功能代码是否顺利执行</returns>
  public static bool TryCatch<T>(this T source, Action<T> action, Action<Exception> failureAction) where T : class
  {
   return source.TryCatch(action,
    failureAction,
    obj => { });
  }

  /// <summary>
  ///  对某对象执行指定功能,并处理异常情况与返回值
  /// </summary>
  /// <typeparam name="T">对象类型</typeparam>
  /// <typeparam name="TResult">返回值类型</typeparam>
  /// <param name="source">值</param>
  /// <param name="func">要对值执行的主功能代码</param>
  /// <param name="failureAction">catch中的功能代码</param>
  /// <param name="successAction">主功能代码成功后执行的功能代码</param>
  /// <returns>功能代码的返回值,如果出现异常,则返回对象类型的默认值</returns>
  public static TResult TryCatch<T, TResult>(this T source, Func<T, TResult> func, Action<Exception> failureAction,
   Action<T> successAction)
   where T : class
  {
   TResult result;
   try
   {
    var u = func(source);
    successAction(source);
    result = u;
   }
   catch (Exception obj)
   {
    failureAction(obj);
    result = default(TResult);
   }
   return result;
  }

  /// <summary>
  ///  对某对象执行指定功能,并处理异常情况与返回值
  /// </summary>
  /// <typeparam name="T">对象类型</typeparam>
  /// <typeparam name="TResult">返回值类型</typeparam>
  /// <param name="source">值</param>
  /// <param name="func">要对值执行的主功能代码</param>
  /// <param name="failureAction">catch中的功能代码</param>
  /// <returns>功能代码的返回值,如果出现异常,则返回对象类型的默认值</returns>
  public static TResult TryCatch<T, TResult>(this T source, Func<T, TResult> func, Action<Exception> failureAction)
   where T : class
  {
   return source.TryCatch(func,
    failureAction,
    obj => { });
  }