using System; using System.Collections.Generic; using System.Linq; using System.Linq.Expressions; using System.Reflection; using System.Text; using System.Threading.Tasks; namespace EasyFrame.Common { public static class LambdaCommon { #region 表示式工具 /// <summary> /// 相當於&&操作 /// ——Author:hellthinker /// </summary> /// <param name="thisFilter">已生成的過濾條件</param> /// <param name="otherFilter">未生成的過濾條件</param> /// <returns>新的過濾</returns> public static Expression GotoAndAlso(this Expression thisFilter, Expression otherFilter) { return Expression.AndAlso(thisFilter, otherFilter); } /// <summary> /// 相當於||操作 /// ——Author:hellthinker /// </summary> /// <param name="thisFilter">已生成的過濾條件</param> /// <param name="otherFilter">未生成的過濾條件</param> /// <returns>新的過濾</returns> public static Expression GotoOrElse(this Expression thisFilter, Expression otherFilter) { return Expression.OrElse(thisFilter, otherFilter); } /// <summary> /// 相當於==操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoEqual(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { return Expression.Equal(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue)); } /// <summary> /// 相當於>=操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoGreaterThanOrEqual<T>(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { //大於或等於 return Expression.GreaterThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(T))); } /// <summary> /// 相當於小於等於操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoLessThanOrEqual<T>(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { //小於或等於 return Expression.LessThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(T))); } /// <summary> /// 相當於!=操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoNotEqual(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { return Expression.NotEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue)); } /// <summary> /// 相當於>=操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoGreaterThanOrEqual(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { //大於或等於 return Expression.GreaterThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue)); } /// <summary> /// 相當於>操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoGreaterThan<T>(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { //大於 return Expression.GreaterThan(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(T))); } /// <summary> /// 相當於小於操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoLessThan<T>(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { //小於 return Expression.LessThan(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(T))); } /// <summary> /// 相當於>=操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoGreaterThanOrEqualByDateTime(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { //大於或等於 return Expression.GreaterThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(DateTime?))); } /// <summary> /// 字串包含 /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoContains(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { return Expression.Call(Expression.Property(thisParameterExpression, propertieName), typeof(string).GetMethod("Contains"), Expression.Constant(propertieValue)); } /// <summary> /// 相當於小於或等於操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoLessThanOrEqualByDateTime(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { //小於或等於 return Expression.LessThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(DateTime?))); } /// <summary> /// 相當於>操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoGreaterThanByDateTime(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { //大於 return Expression.GreaterThan(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(DateTime?))); } /// <summary> /// 相當於小於操作 /// ——Author:hellthinker /// </summary> /// <param name="thisParameterExpression">查詢物件</param> /// <param name="propertieName">屬性名稱</param> /// <param name="propertieValue">屬性值</param> /// <returns>新的過濾</returns> public static Expression GotoLessThanByDateTime(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { //小於 return Expression.LessThan(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(DateTime?))); } /// <summary> /// 包含操作 相當餘 a=> arr.Contains(a.ID) /// </summary> /// <param name="thisParameterExpression"></param> /// <param name="propertieName"></param> /// <param name="propertieValue"></param> /// <returns></returns> public static Expression ContainsOperations(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { MethodInfo method = null; MemberExpression member = Expression.Property(thisParameterExpression, propertieName); var containsMethods = typeof(Enumerable).GetMethods(BindingFlags.Static | BindingFlags.Public).Where(m => m.Name == "Contains"); foreach (var m in containsMethods) { if (m.GetParameters().Count() == 2) { method = m; break; } } method = method.MakeGenericMethod(member.Type); var exprContains = Expression.Call(method, new Expression[] { Expression.Constant(propertieValue), member }); return exprContains; } /// <summary> /// 包含操作 相當於 a=>a.ID.Contains(key) /// </summary> /// <param name="thisParameterExpression"></param> /// <param name="propertieName"></param> /// <param name="propertieValue"></param> /// <returns></returns> public static Expression Contains(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue) { var propertyExp = Expression.Property(thisParameterExpression, propertieName); MethodInfo method = typeof(string).GetMethod("Contains", new[] { typeof(string) }); var someValue = Expression.Constant(propertieValue, typeof(string)); var containsMethodExp = Expression.Call(propertyExp, method, someValue); return containsMethodExp; } #endregion } }