小编MrW*_*rus的帖子

我有一个 IQueryable 扩展方法，用于减少在 EF Core DbContext 模型中搜索多个字段所需的样板代码量：

public static IQueryable<TEntity> WherePropertyIsLikeIfStringIsNotEmpty<TEntity>(this IQueryable<TEntity> query,
    string searchValue, Expression<Func<TEntity, string>> propertySelectorExpression)
{
    if (string.IsNullOrEmpty(searchValue) || !(propertySelectorExpression.Body is MemberExpression memberExpression))
    {
        return query;
    }
    
    // get method info for EF.Functions.Like
    var likeMethod = typeof(DbFunctionsExtensions).GetMethod(nameof(DbFunctionsExtensions.Like), new []
    {
        typeof(DbFunctions),
        typeof(string),
        typeof(string)
    });
    var searchValueConstant = Expression.Constant($"%{searchValue}%");
    var dbFunctionsConstant = Expression.Constant(EF.Functions);
    var propertyInfo = typeof(TEntity).GetProperty(memberExpression.Member.Name);
    var parameterExpression = Expression.Parameter(typeof(TEntity));
    var propertyExpression = Expression.Property(parameterExpression, propertyInfo);
    
    
    var callLikeExpression = Expression.Call(likeMethod, dbFunctionsConstant, propertyExpression, searchValueConstant);
    var lambda = Expression.Lambda<Func<TEntity, bool>>(callLikeExpression, …