Question

我有3个单选按钮Any，Single和Multiple。它们是网格视图中记录的过滤器。

Any不对查询应用任何条件。

Single和Multiple分别对查询1或2应用检查条件。

此代码有一些错误，但我无法解决或找不到解决方法。

public void ApplyFilter()
    {
        var subQueryGroup = from hero in HDA.Hero_Group
                       where hero.GroupID == ((byte)cboGroup.SelectedValue)
                       select hero.HeroID;

        #region Case1
        /*
        var subQuerySpec = from h in HDA.Hero_Speciality
                           select new { h.HeroID, h.SpecID };

        if (rbtnMulti.Checked)
            subQuerySpec = subQuerySpec.Where(h => h.SpecID == 1);
        if (rbtnSingle.Checked)
            subQuerySpec = subQuerySpec.Where(h => h.SpecID == 2);
        */
        #endregion

        #region Case2
        var subQuerySpec = from h in HDA.Hero_Speciality
                           select h.HeroID;

        if (rbtnMulti.Checked)
            subQuerySpec = subQuerySpec.Where(h => h.SpecID == 1); // error @ h.SpecID
        if (rbtnSingle.Checked)
            subQuerySpec = subQuerySpec.Where(h => h.SpecID == 2); // error @ h.SpecID
        #endregion

        var q = from o in HDA.HeroInfoes
                orderby o.HeroRarity
                select new Hero
                {
                    ID = o.ID,
                    Name = o.HeroName,
                    RarityID = o.HeroRarity,
                    Rarity = o.Rarity.RarityName,
                    Speed = o.Initiative,
                    Attack = o.Attack,
                    Target = o.Attack2.Description
                };
        if (cboRarity.SelectedIndex != 0 && cboRarity.SelectedIndex != -1)
            q = q.Where(o => o.RarityID == cboRarity.SelectedIndex);
        if (cboGroup.SelectedIndex != 0 && cboGroup.SelectedIndex != -1)
            q = q.Where(o => subQueryGroup.Contains(o.ID));
        if (cboSpeed.SelectedIndex != 0 && cboSpeed.SelectedIndex != -1)
            q = q.Where(o => o.Speed == cboSpeed.SelectedIndex);

        q = q.Where(o => subQuerySpec.Contains(o.ID)); // Case1(error) , Case2(OK)
        ViewResults(q);
    }

我在Case1得到的错误是：

“实例参数：无法从'System.Linq.IQueryable'转换为'System.Linq.ParallelQuery' “
“'System.Linq.IQueryable'不包含'Contains'的定义和最佳扩展方法重载'System.Linq.ParallelEnumerable.Contains（System.Linq.ParallelQuery，TSource）'有一些无效参数“

我在Case2遇到的错误是：

” 'short'不包含'SpecID'的定义，并且没有扩展方法'SpecID'可以找到接受类型'short'的第一个参数（你是否缺少using指令或汇编引用？）“

请注意，我做了类似于群组过滤的事情，但在这种情况下，我没有收到任何错误。

Answer 1

var subQuerySpec = from h in HDA.Hero_Speciality
                           select new { h.HeroID, h.SpecID };

        if (rbtnMulti.Checked)
            subQuerySpec = from h in subQuerySpec
                           where h.SpecID == 1
                           select h;

        if (rbtnSingle.Checked)
            subQuerySpec = from h in subQuerySpec
                           where h.SpecID == 2
                           select h;

LINQ to Entities：Lambda表达式错误

1 个答案: