带有动态增长的where子句的Linq to entity

using (var context = new YourDbContext())
{
    var query = context.YourEntities.AsQueryable();

    if (!string.IsNullOrEmpty(userInput.Keyword1))
    {
        query = query.Where(e => e.Field1.Contains(userInput.Keyword1));
    }

    if (!string.IsNullOrEmpty(userInput.Keyword2))
    {
        query = query.Where(e => e.Field2.Contains(userInput.Keyword2));
    }

    // 更多条件可以根据需要添加...

    var results = query.ToList();
}

public static IQueryable<T> ApplyDynamicFilters<T>(this IQueryable<T> source, List<FilterCriteria> filters)
{
    var parameter = Expression.Parameter(typeof(T), "x");
    var predicateBody = default(Expression);

    foreach (var filter in filters)
    {
        var filterExpression = Expression.Equal(
            Expression.Property(parameter, filter.FieldName),
            Expression.Constant(filter.FieldValue)
        );

        predicateBody = predicateBody == null ? filterExpression : Expression.AndAlso(predicateBody, filterExpression);
    }

    var lambda = Expression.Lambda(predicateBody, parameter);
    return source.Where(lambda);
}