EF 动态查询

Expression<Func<T, bool>> filter = o => true;

if (!string.IsNullOrWhiteSpace(req.UserName))
filter = x => x.UserName == req.UserName;

if (!string.IsNullOrWhiteSpace(req.RealName))
filter = x => x.Realname.Contains(req.RealName);

if (req.DepartmentID > 0)
filter = x => x.DepartmentID == req.DepartmentID;

if (req.RoleID > 0)
filter = x => x.RoleID == req.RoleID;

var list = _dbService.Repository<T>().QueryPage(req.PageNumber, req.PageSize, out TotalCount, filter, x=>x.OrderBy(o=>o.ID)).ToList();

 

参考：https://blog.csdn.net/qq_35534449/article/details/81240404