32 lines
1.2 KiB
C#
32 lines
1.2 KiB
C#
using System;
|
|
using System.Collections.Generic;
|
|
using System.Linq;
|
|
using System.Linq.Expressions;
|
|
using System.Text;
|
|
|
|
namespace Mini.Model
|
|
{
|
|
|
|
public static class PredicateBuilder
|
|
{
|
|
public static Expression<Func<T, bool>> True<T>() { return f => true; }
|
|
public static Expression<Func<T, bool>> False<T>() { return f => false; }
|
|
//false
|
|
public static Expression<Func<T, bool>> Or<T>(this Expression<Func<T, bool>> expr1,
|
|
Expression<Func<T, bool>> expr2)
|
|
{
|
|
var invokedExpr = Expression.Invoke(expr2, expr1.Parameters.Cast<Expression>());
|
|
return Expression.Lambda<Func<T, bool>>
|
|
(Expression.Or(expr1.Body, invokedExpr), expr1.Parameters);
|
|
}
|
|
//true
|
|
public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> expr1,
|
|
Expression<Func<T, bool>> expr2)
|
|
{
|
|
var invokedExpr = Expression.Invoke(expr2, expr1.Parameters.Cast<Expression>());
|
|
return Expression.Lambda<Func<T, bool>>
|
|
(Expression.And(expr1.Body, invokedExpr), expr1.Parameters);
|
|
}
|
|
}
|
|
}
|