表达式与条件组合

/// <summary>
/// 表达式与条件组合
/// </summary>
public static Expression<Func<T, bool>> AndCombine<T>(this Expression<Func<T, bool>> A, Expression<Func<T, bool>> B)
{
var sum = Expression.AndAlso(A.Body, Expression.Invoke(B, A.Parameters[0])); // here is the magic
return Expression.Lambda<Func<T, bool>>(sum, A.Parameters);
}

            var func = predicate.Compile();