C# 我正在为我的项目制作搜索功能。我如何优化我的查询，因为它有这么多；如有其他",；声明？

我正在为我的项目创建搜索功能。我如何优化我的查询，因为它有这么多

if-else

语句

我使用

if-else

语句来检查是否有空值，但它增加了代码的复杂性和内存。我想减少它；如何优化查询，使查询中的

if-else

语句数最少

public List<tbltask> gettaskssdata(int c, int userid, string a, string StartDate, string EndDate, string ProjectID, string statusid)
{
    List<tbltask> tbtask = new List<tbltask>();

    var selectproject = entity.tbluserprojects.Where(x => x.user_id == userid).Select(x => x.Projectid);

    if (statusid != "" && ProjectID != "" && a != "" && StartDate != "" && EndDate != "")
    {
        int pid = Convert.ToInt32(ProjectID);
        int sid = Convert.ToInt32(statusid);
        DateTime sdate = Convert.ToDateTime(StartDate).Date;
        DateTime edate = Convert.ToDateTime(EndDate).Date;
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.company_id == c) && (x.tblproject.ProjectId == pid) && (x.tblstatu.StatusId == sid) && (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a)) && (x.StartDate >= sdate && x.EndDate <= edate)).OrderByDescending(x => x.ProjectId).ToList();
    }
    else if (statusid == "" && ProjectID != "" && a != "" && StartDate != "" && EndDate != "")
    {
        int pid = Convert.ToInt32(ProjectID);
        DateTime sdate = Convert.ToDateTime(StartDate).Date;
        DateTime edate = Convert.ToDateTime(EndDate).Date;
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.company_id == c) && (x.tblproject.ProjectId == pid) && (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a)) && (x.StartDate >= sdate && x.EndDate <= edate)).OrderByDescending(x => x.ProjectId).ToList();
    }
    else if (ProjectID == "" && statusid != "" && a != "" && StartDate != "" && EndDate != "")
    {
        int sid = Convert.ToInt32(statusid);
        DateTime sdate = Convert.ToDateTime(StartDate).Date;
        DateTime edate = Convert.ToDateTime(EndDate).Date;
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.company_id == c) && (x.tblstatu.StatusId == sid) && (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a)) && (x.StartDate >= sdate && x.EndDate <= edate)).OrderByDescending(x => x.ProjectId).ToList();
    }
    else if(ProjectID!="" && StartDate == "" && EndDate == "" && statusid == ""  && a == "")
    {
        int pid = Convert.ToInt32(ProjectID);
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.company_id == c) && (x.tblproject.ProjectId == pid)).OrderByDescending(x => x.ProjectId).ToList();

    }
    else if(statusid!="" && ProjectID=="" && StartDate == "" && EndDate == ""  && a == "")
    {
        int sid = Convert.ToInt32(statusid);
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.company_id == c) && (x.tblstatu.StatusId == sid) ).OrderByDescending(x => x.ProjectId).ToList();
    }
    else if (a == "" && StartDate != "" && EndDate != "" && ProjectID != "")
    {
        int pid = Convert.ToInt32(ProjectID);
        DateTime sdate = Convert.ToDateTime(StartDate).Date;
        DateTime edate = Convert.ToDateTime(EndDate).Date;
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.ProjectId == pid) && (x.StartDate >= sdate && x.EndDate <= edate)).OrderByDescending(x => x.ProjectId).ToList();

    }
    else if (StartDate == "" && EndDate == "" && statusid != "" && ProjectID != "" && a != "")
    {
        int pid = Convert.ToInt32(ProjectID);
        int sid = Convert.ToInt32(statusid);
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.company_id == c) && (x.tblproject.ProjectId == pid) && (x.tblstatu.StatusId == sid) && (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a))).OrderByDescending(x => x.ProjectId).ToList();
    }
    else if (a == "" && StartDate == "" && EndDate == "" && ProjectID != "" && statusid != "")
    {
        int pid = Convert.ToInt32(ProjectID);
        int sid = Convert.ToInt32(statusid);
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Include(x => x.tblstatu).Where(x => selectproject.Contains(x.ProjectId) && x.tblproject.company_id == c && x.tblproject.ProjectId == pid && x.tblstatu.StatusId == sid).OrderByDescending(x => x.ProjectId).ToList();
    }
    else if (a != "" && StartDate == "" && EndDate == "" && ProjectID == "" && statusid == "")
    {
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.company_id == c) && (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a))).OrderByDescending(x => x.ProjectId).ToList();

    }
    else if (a != "" && ProjectID != "" && StartDate == "" && EndDate == "" && statusid == "")
    {
        int pid = Convert.ToInt32(ProjectID);
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.company_id == c) && (x.tblproject.ProjectId == pid) && (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a))).OrderByDescending(x => x.ProjectId).ToList();
    }
    else if (a != "" && StartDate != "" && EndDate != "" && ProjectID == "" && statusid == "")
    {
        DateTime sdate = Convert.ToDateTime(StartDate).Date;
        DateTime edate = Convert.ToDateTime(EndDate).Date;
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && (x.tblproject.company_id == c) && (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a)) && (x.StartDate >= sdate && x.EndDate <= edate)).OrderByDescending(x => x.ProjectId).ToList();
    }
    else
    {
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).Where(x => selectproject.Contains(x.ProjectId) && x.tblproject.company_id == c).OrderByDescending(x => x.ProjectId).ToList();
    }
    return tbtask;
}

public List gettaskssdata（int c，int userid，string a，string StartDate，string EndDate，string ProjectID，string statusid）
{
List tbtask=新列表（）；
var selectproject=entity.tbluserprojects.Where（x=>x.user\u id==userid）；
如果（statusid！=“”&&ProjectID！=“”&&a！=“”&&StartDate！=“”&&EndDate！=“”）
{
int pid=转换为32（ProjectID）；
int sid=Convert.ToInt32（statusid）；
DateTime sdate=Convert.ToDateTime（StartDate）.Date；
DateTime-edate=Convert.ToDateTime（EndDate）.Date；
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.其中（x=>selectproject.Contains（x.projectd）和&（x.tblproject.company_id==c）和&（x.tblproject.projectd==pid）和&（x.tblstatu.StatusId==sid）和&（x.TaskName.Contains（a）| | | x.tbUser.User.User.User_name.Contains（a））&（a））&（x.StartDate>&x.EndDate&&x.told）项目日期）；
}
否则如果（statusid==“”&&ProjectID！=“”&&a！=“”&&StartDate！=“”&&EndDate！=“”）
{
int pid=转换为32（ProjectID）；
DateTime sdate=Convert.ToDateTime（StartDate）.Date；
DateTime-edate=Convert.ToDateTime（EndDate）.Date；
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.其中（x=>selectproject.Contains（x.projectd）&&（x.tblproject.company_id==c）&（x.tblproject.projectd==pid）&（x.TaskName.Contains（a）| | x.tbUser.User.User_name.Contains（a））&（x.StartDate>=sdate&&x.EndDate x.projectd）.ToList（）；
}
else if（ProjectID==“”&&statusid！=“”&&a！=“”&&StartDate！=“”&&EndDate！=“”）
{
int sid=Convert.ToInt32（statusid）；
DateTime sdate=Convert.ToDateTime（StartDate）.Date；
DateTime-edate=Convert.ToDateTime（EndDate）.Date；
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.其中（x=>selectproject.Contains（x.projectd）&（x.tblproject.company_id==c）&（x.tblstatu.StatusId==sid）&（x.TaskName.Contains（a）| | x.tbUser.User.User_name.Contains（a））&（x.StartDate>=sdate&&x.EndDate x.projectd）.ToList（）；
}
else if（ProjectID！=“”&&StartDate=“”&&EndDate=“”&&statusid=“”&&a=“”）
{
int pid=转换为32（ProjectID）；
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.其中（x=>selectproject.Contains（x.ProjectId）&&&（x.tblproject.company_id==c）&&（x.tblproject.ProjectId==pid））.OrderByDescending（x=>x.ProjectId）.ToList（）；
}
else if（statusid！=“”&&ProjectID=“”&&StartDate=“”&&EndDate=“”&&a=“”）
{
int sid=Convert.ToInt32（statusid）；
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.其中（x=>selectproject.Contains（x.ProjectId）和&（x.tblproject.company_id==c）和&（x.tblstatu.StatusId==sid））.OrderByDescending（x=>x.ProjectId）.ToList（）；
}
如果（a==“”&&StartDate！==“”&&EndDate！==“”&&ProjectID！=“”）
{
int pid=转换为32（ProjectID）；
DateTime sdate=Convert.ToDateTime（StartDate）.Date；
DateTime-edate=Convert.ToDateTime（EndDate）.Date；
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.其中（x=>selectproject.Contains（x.ProjectId）&&&（x.tblproject.ProjectId==pid）&&（x.StartDate>=sdate&&x.EndDate x.ProjectId）.ToList（）；
}
else if（StartDate==“”&&EndDate==“”&&statusid！=“”&&ProjectID！=“”&&a！=“”）
{
int pid=转换为32（ProjectID）；
int sid=Convert.ToInt32（statusid）；
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.其中（x=>selectproject.Contains（x.projectd）和&（x.tblproject.company_id==c）&（x.tblproject.ProjectId==pid）和&（x.tblstatu.StatusId==sid）和&（x.TaskName.Contains（a）| | | x.tbUser.User.User_name.Contains（a））.OrderByDescending（x=>projectd）.ToList（）；
}
否则如果（a==“”&&StartDate==“”&&EndDate==“”&&ProjectID！=“”&&statusid！=“”）
{
int pid=转换为32（ProjectID）；
int sid=Convert.ToInt32（statusid）；
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.Include（x=>x.tblstatu）.其中（x=>selectproject.Contains（x.projectd）&&x.tblproject.company_id==c&&x.tblproject.ProjectId==pid&&x.tblstatu.StatusId==sid）.OrderByDescending（x=>x.projectd）.ToList（）；
}
如果（a！=“”&&StartDate=“”&&EndDate=“”&&ProjectID=“”&&statusid=“”）出现异常
{
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.其中（x=>selectproject.Contains（x.projectd）&&&（x.tblproject.company_id==c）&&（x.TaskName.Contains（a）| | x.tbUser.User_name.Contains（a））.OrderByDescending（x=>x.projectd.ToList（）；
}
如果（a！=“”&&ProjectID！=“”&&StartDate=“”&&EndDate=“”&&statusid=“”）为
{
int pid=转换为32（ProjectID）；
tbtask=entity.tbltasks.Include（x=>x.tblproject）.Include（x=>x.tbUser）.其中（x=>selectproject.Contains（x.projectd）&&&（x.tblproject.company_id==c）&&（x.tblproject.ProjectId==pid）&（x.TaskName.Contains（a）| | x.tbUser.User.User_name.Contains（a））.OrderByDescending（x=>x.projectd）.ToList（）；
}
如果（a！=“”&&StartDate！=“”&&EndDate！=“”&&ProjectID=“”&&statusid=“”）为else，则为
{
DateTime sdate=Convert.ToDateTime（StartDate）.Date；
DateTime edate=Conv
public List<tbltask> gettaskssdata(int? c, int? userid, string a, DateTime? StartDate, DateTime? EndDate, int? ProjectID, int? statusid)
{

tbtask = entity.tbltasks.Where(x => (!c.HasValue || x.tblproject.company_id == c.Value) && ...)

 public List<tbltask> gettaskssdata(int? c, int? userid, string a, string StartDate, string EndDate, int? ProjectID, int? statusid)
    {
        List<tbltask> tbtask = new List<tbltask>();
        DateTime sdate = (StartDate != "") ? Convert.ToDateTime(StartDate).Date : new DateTime();
        DateTime edate = (EndDate != "") ? Convert.ToDateTime(EndDate).Date : new DateTime();
        tbtask = entity.tbltasks.Include(x => x.tblproject).Include(x => x.tbUser).
            Where(x => x.tblproject.company_id == c
                && (ProjectID == 0 || ProjectID == x.tblproject.ProjectId)
                && (statusid == 0 || statusid == x.tblstatu.StatusId)
                && (a == "" || (x.TaskName.Contains(a) || x.tbUser.User_name.Contains(a)))
                && ((StartDate == "" && EndDate == "") || ((x.StartDate >= sdate && x.EndDate <= edate)))).ToList();



        return tbtask;


    }