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 表达式工具
/// <summary>
/// 相当于&&操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisFilter">已生成的过滤条件</param>
/// <param name="otherFilter">未生成的过滤条件</param>
/// <returns>新的过滤</returns>
public static Expression GotoAndAlso(this Expression thisFilter, Expression otherFilter)
{
return Expression.AndAlso(thisFilter, otherFilter);
}
/// <summary>
/// 相当于||操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisFilter">已生成的过滤条件</param>
/// <param name="otherFilter">未生成的过滤条件</param>
/// <returns>新的过滤</returns>
public static Expression GotoOrElse(this Expression thisFilter, Expression otherFilter)
{
return Expression.OrElse(thisFilter, otherFilter);
}
/// <summary>
/// 相当于==操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoEqual(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
return Expression.Equal(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue));
}
/// <summary>
/// 相当于>=操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoGreaterThanOrEqual<T>(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
//大于或等于
return Expression.GreaterThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(T)));
}
/// <summary>
/// 相当于小于等于操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoLessThanOrEqual<T>(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
//小于或等于
return Expression.LessThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(T)));
}
/// <summary>
/// 相当于!=操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoNotEqual(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
return Expression.NotEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue));
}
/// <summary>
/// 相当于>=操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoGreaterThanOrEqual(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
//大于或等于
return Expression.GreaterThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue));
}
/// <summary>
/// 相当于>操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoGreaterThan<T>(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
//大于
return Expression.GreaterThan(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(T)));
}
/// <summary>
/// 相当于小于操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoLessThan<T>(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
//小于
return Expression.LessThan(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(T)));
}
/// <summary>
/// 相当于>=操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoGreaterThanOrEqualByDateTime(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
//大于或等于
return Expression.GreaterThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(DateTime?)));
}
/// <summary>
/// 字符串包含
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</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>
/// 相当于小于或等于操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoLessThanOrEqualByDateTime(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
//小于或等于
return Expression.LessThanOrEqual(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(DateTime?)));
}
/// <summary>
/// 相当于>操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoGreaterThanByDateTime(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
//大于
return Expression.GreaterThan(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(DateTime?)));
}
/// <summary>
/// 相当于小于操作
/// ——Author:hellthinker
/// </summary>
/// <param name="thisParameterExpression">查询对象</param>
/// <param name="propertieName">属性名称</param>
/// <param name="propertieValue">属性值</param>
/// <returns>新的过滤</returns>
public static Expression GotoLessThanByDateTime(this ParameterExpression thisParameterExpression, string propertieName, object propertieValue)
{
//小于
return Expression.LessThan(Expression.Property(thisParameterExpression, propertieName), Expression.Constant(propertieValue, typeof(DateTime?)));
}
/// <summary>
/// 包含操作 相当余 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)
{
)
{
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 相当于 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
}
}