/// <summary>
/// 使用指定的查询对象查询题目句柄。
/// </summary>
/// <param name="query">为查询提供参数。</param>
/// <returns>一个列表，该列表中包含了所有的查询结果。</returns>
/// <exception cref="ArgumentNullException"/>
/// <exception cref="ArgumentOutOfRangeException"/>
public IList <ProblemHandle> QueryProblems(ProblemArchieveQueryParameter query)
{
if (query == null)
{
throw new ArgumentNullException(nameof(query));
}
if (query.QueryByTitle && query.Title == null)
{
throw new ArgumentNullException(nameof(query.Title));
}
if (query.QueryBySource && query.Source == null)
{
throw new ArgumentNullException(nameof(query.Source));
}
if (query.QueryByAuthor && query.Author == null)
{
throw new ArgumentNullException(nameof(query.Author));
}
if (query.Page == null)
{
throw new ArgumentNullException(nameof(query.Page));
}
if (query.Page.Page <= 0 || query.Page.EntriesPerPage <= 0)
{
throw new ArgumentOutOfRangeException(nameof(query.Page));
}
IQueryable <ProblemEntity> set = m_context.GetAllProblemEntities();
// 根据查询参数执行相应的查询，动态维护查询基础数据集。
if (query.QueryByTitle)
{
set = ProblemArchieveDataContext.QueryProblemEntitiesByTitle(set, query.Title);
}
if (query.QueryBySource)
{
set = ProblemArchieveDataContext.QueryProblemEntitiesBySource(set, query.Source);
}
if (query.QueryByAuthor)
{
set = ProblemArchieveDataContext.QueryProblemEntitiesByAuthor(set, query.Author);
}
// 执行分页。
set = set.Page(query.Page.Page, query.Page.EntriesPerPage);
List <ProblemHandle> handleList = new List <ProblemHandle>();
foreach (ProblemEntity entity in set)
{
handleList.Add(ProblemHandle.FromProblemEntity(entity));
}
return(handleList);
}
private ProblemArchieveDataContext m_context; // 数据上下文
/// <summary>
/// 初始化 ProblemArchieveManager 类的新实例。
/// </summary>
private ProblemArchieveManager()
{
m_context = new ProblemArchieveDataContext();
}
