NReco.LambdaParser使用案例

使用案例集合：

 private async void RuleEngine_Click(object sender, EventArgs e){#region 获取变量string expression = this.Rule.Text.Trim();string pattern = @"\$(.*?)\$";MatchCollection matches = Regex.Matches(expression, pattern);foreach (Match match in matches){string variableName = match.Groups[1].Value;}#endregion#region 执行器初始化var lambdaParser = new LambdaParser();lambdaParser.AllowVars = true;#endregion#region 变量初始化var tagsql = string.Empty;var dictLast = new Dictionary<string, object>();#endregion#region 常用方法与数据定义dictLast["PI"] = 3.14M;dictLast["Now"] = DateTime.Now;dictLast["Not"] = (Func<bool, bool>)((t) => !t);dictLast["Max"] = (Func<decimal, decimal, decimal>)((a, b) => Math.Max(a, b));dictLast["Yes"] = true;dictLast["No"] = false;dictLast["arr"] = new double[] { 1.5, 2.5 };dictLast["dic"] = new Dictionary<string, int>(){{"apple", 1},{"banana", 2},{"orange", 3}};dictLast["Alert"] = (Func<string, string>)((msg) => AlertAsync(msg));#endregion#region 判断字符是否正确输入string input = "Now.ToString(\"yyyy-MM-dd/HH\")";string backslash = @"(?<!\\)"""; // 匹配没有被转义的双引号MatchCollection matches2 = Regex.Matches(input, backslash);if (matches.Count > 0)Console.WriteLine("双引号没有被正确转义");elseConsole.WriteLine("双引号都有正确转义");#endregion#region testConsole.WriteLine(lambdaParser.Eval("Now.ToString(\"yyyy-MM-dd/HH\")", dictLast));Console.WriteLine(lambdaParser.Eval("Max(Max(3,4),2)", dictLast));Console.WriteLine(lambdaParser.Eval("arr[0]+arr[1]", dictLast)); // -> 4Console.WriteLine(lambdaParser.Eval("dic[\"apple\"]+arr[1]", dictLast)); // -> 3.5Console.WriteLine(lambdaParser.Eval("(new[]{1,2})[1]", dictLast)); // 2#endregionint i = 0;foreach (var v in this.Variables.Text.Trim().Split(',')){if (i == 0)tagsql = this.DataSet1.Text.Trim();elsetagsql = this.DataSet2.Text.Trim();var rtTagInfos = await _dbInstance.DBOperation.QueryAsync<dynamic>(tagsql);if (rtTagInfos.Count() == 1){var dictSingle = ((IDictionary<string, object>)rtTagInfos.FirstOrDefault()).ToDictionary(kvp => kvp.Key.Split(new[] { '(', ')' }).LastOrDefault(), kvp => kvp.Value);dictLast = dictLast.Union(dictSingle).ToDictionary(x => x.Key, x => x.Value);}else{#region 没有去重//var keyValuePairs = new List<KeyValuePair<string, object>>();//foreach (var record in rtTagInfos)//{//    int i = 0;//    string propertyName = string.Empty;//    foreach (var property in (IDictionary<string, object>)record)//    {//        if (i == 0)//            propertyName = Convert.ToString(property.Value);//        else//            keyValuePairs.Add(new KeyValuePair<string, object>(propertyName, property.Value));//        i = i + 1;//    }//}//var dictlist = keyValuePairs.ToDictionary(kvp => kvp.Key, kvp => kvp.Value);#endregionvar keyValuePairs = new HashSet<KeyValuePair<string, object>>();Parallel.ForEach(rtTagInfos, (record) =>{int i = 0;string propertyName = string.Empty;foreach (var property in (IDictionary<string, object>)record){if (i == 0){propertyName = Convert.ToString(property.Value);}else{var keyValuePair = new KeyValuePair<string, object>(propertyName, property.Value);lock (keyValuePairs){if (!keyValuePairs.Contains(keyValuePair)){if (!keyValuePairs.Any(kvp => kvp.Key == keyValuePair.Key)){keyValuePairs.Add(keyValuePair);}}}}i = i + 1;}});var dictlist = keyValuePairs.ToDictionary(kvp => kvp.Key, kvp => kvp.Value);dictLast = dictLast.Union(dictlist).ToDictionary(x => x.Key, x => x.Value);}i = i + 1;}var res = lambdaParser.Eval(this.Rule.Text.Trim().Replace("$", ""), dictLast);MessageBox.Show(res?.ToString());}public string AlertAsync(string msg){var time = "SELECT NOW() as now";var rtTagInfos = AsyncHelper.RunSync(() => _dbInstance.DBOperation.QueryFirstOrDefaultAsync<DateTime>(time));return msg + rtTagInfos.ToString();}

$reportvalue$<1234?"1":Alert("告警:")