Linq动态查询与模糊查询

IList<Department> mDepartmentLst = new List<Department>();IList<Employee> mEmployeeLst = new List<Employee>();mDepartmentLst.Add(new Department() { Id = 1, DeptNo = "001", DeptName = "开发部", IsBusiness = false });mDepartmentLst.Add(new Department() { Id = 2, DeptNo = "002", DeptName = "B2C 商务部", IsBusiness = true });mDepartmentLst.Add(new Department() { Id = 3, DeptNo = "003", DeptName = "B2B 商务部", IsBusiness = true });mDepartmentLst.Add(new Department() { Id = 4, DeptNo = "004", DeptName = "人事部", IsBusiness = false });mEmployeeLst.Add(new Employee() { Id = 1, DeptId = 1, EmpNo = "NO001", EmpName = "xushengtao" });mEmployeeLst.Add(new Employee() { Id = 1, DeptId = 1, EmpNo = "NO002", EmpName = "fankaijian" });mEmployeeLst.Add(new Employee() { Id = 1, DeptId = 4, EmpNo = "NO003", EmpName = "wangguoqin" });int mPageSize = 2;int mTotalCount = 0;Expression mWhereExpression;          // Filter clause (查询语句)// Get current request pagestring mCurPage = "1"; ;// Linq param which represent the search object (查询对象代替符)ParameterExpression mLinqParam = Expression.Parameter(typeof(Department), "p"); //begin 处理“IsBusiness=true”//创建一个表示访问属性的 MemberExpressionMemberExpression memberExpression = Expression.Property(mLinqParam, typeof(Department).GetProperty("IsBusiness"));ConstantExpression constantExpression = Expression.Constant(false);mWhereExpression = Expression.Equal(memberExpression, constantExpression);//endstring mDeptName = "人事部";if (!String.IsNullOrEmpty(mDeptName)){mWhereExpression = Expression.And(mWhereExpression, Expression.Call(Expression.Property(mLinqParam,typeof(Department).GetProperty("DeptName")), typeof(String).GetMethod("Contains"),new Expression[] { Expression.Constant(mDeptName) }));}var mLambdaWhere = (Expression<Func<Department, bool>>)Expression.Lambda<Func<Department, bool>>(mWhereExpression,new ParameterExpression[] { mLinqParam });Func<Department, String> mLambdaOrder = p => p.DeptNo;mTotalCount = mDepartmentLst.AsQueryable().Where(mLambdaWhere).Count();var list = from o in mDepartmentLst.AsQueryable().Where(mLambdaWhere).OrderBy(mLambdaOrder).Skip((int.Parse(mCurPage) - 1) * mPageSize).Take(mPageSize)join c in mEmployeeLst on o.Id equals c.DeptIdselect new{o.DeptNo,o.DeptName,o.IsBusiness,c.DeptId,c.EmpNo,c.EmpName};