/// <summary>
/// Combines the first predicate with the second using the logical "or".
/// </summary>
public static Expression <Func <T, bool> > Or <T>(this Expression <Func <T, bool> > first, Expression <Func <T, bool> > second)
{
return(first.Compose(second, Expression.OrElse));
}
public static Expression <Func <T, bool> > And <T> (this Expression <Func <T, bool> > first, Expression <Func <T, bool> > second)
{
return(first.Compose <Func <T, bool> > (second, new Func <Expression, Expression, Expression> (Expression.And)));
}
/// <summary>
/// Combines the first predicate with the second using the logical "and".
/// </summary>
public static Expression <Func <T, bool> > And <T>(this Expression <Func <T, bool> > first, Expression <Func <T, bool> > second)
{
return(first.Compose(second, Expression.AndAlso));
}
/// <summary>
/// 以 Expression.OrElse 组合两个Expression表达式
/// </summary>
/// <typeparam name="T">表达式的主实体类型</typeparam>
/// <param name="first">第一个Expression表达式</param>
/// <param name="second">要组合的Expression表达式</param>
/// <returns>组合后的表达式</returns>
public static Expression <Func <T, bool> > Or <T>(this Expression <Func <T, bool> > first, Expression <Func <T, bool> > second)
{
first.CheckNotNull("first");
second.CheckNotNull("second");
return(first.Compose(second, Expression.OrElse));
}