使用linq排序网格视图列

本文关键字：视图 网格 排序 linq 使用 | 更新日期: 2023-09-27 18:11:22

我将数据绑定到gridview的模板字段，如:

  <asp:TemplateField HeaderText="Business Objective" SortExpression="BusinessObjective.BusinessObjectiveText">
     <ItemTemplate>
        <asp:Label ID="lblBusinessObjectiveText" runat="server" Text='<%#DataBinder.Eval(Container.DataItem, "BusinessObjective.BusinessObjectiveText") %>'></asp:Label>
     </ItemTemplate>
  </asp:TemplateField>

在代码后面，我只是绑定列表到网格视图:

    gvBussinessRisks.DataSource = this.BusinessRiskList;
    gvBussinessRisks.DataBind();

清单类型为"商业风险"。实体结构类似于

public class BusinessRisk
{
    public BusinessRisk()
    {
        BusinessObjective BusinessObjective = new BusinessObjective();
    }
    public int? BusinessRiskId { get; set; }
    public int ObjectiveId { get; set; }
    public string BusinessRiskText { get; set; }
    public string Description { get; set; }
    public bool IsActive { get; set; }
    public long ActionedBy { get; set; }
    public long? DelegatedTo { get; set; }
    public int? LastLogId { get; set; }
    public int AppOwnerId { get; set; }
    public BusinessObjective BusinessObjective { get; set; }
}

我的businessoobjectject类有一个名为"businessobjecttext"的属性，我将它绑定到网格视图中的一个列。

但是当我试图排序这一列时，我得到错误。

我的排序事件如下:

List<BusinessRisk> sortedList = this.BusinessRiskList;
    sortedList.Sort(new GenericComparer<BusinessRisk>(e.SortExpression, (SortDirection)Enum.Parse(typeof(SortDirection), GetSortDirection(e.SortExpression))));
    gvBussinessRisks.DataSource = sortedList;
    gvBussinessRisks.DataBind();

和"GenericComparer"类是:

public class GenericComparer<T> : IComparer<T>
{
    private string sortExpression;
    private SortDirection sortDirection;
    public GenericComparer(string sortExpression, SortDirection sortDirection)
    {
        this.sortExpression = sortExpression;
        this.sortDirection = sortDirection;
    }
    public int Compare(T x, T y)
    {
        PropertyInfo propertyInfo = typeof(T).GetProperty(sortExpression);
        IComparable obj1 = (IComparable)propertyInfo.GetValue(x, null);
        IComparable obj2 = (IComparable)propertyInfo.GetValue(y, null);

        if (SortDirection == SortDirection.Ascending)
        {
            if (obj1 != null)
                return obj1.CompareTo(obj2);
            return 0;
        }
        else
        {
            if (obj1 != null)
                return obj2.CompareTo(obj1);
            return 0;
        }
    }
    public SortDirection SortDirection
    {
        get { return this.sortDirection; }
        set { this.sortDirection = value; }
    }

}

当我试图将此列排序为GenericComparer类(方法:比较)时，我得到propertyInfo作为null。如果我使用BusinessRisk的属性进行排序，那么排序就会正确发生，但在这里，我试图使用bussinessoobjective类的属性之一进行排序。

我试了谷歌，但没有得到任何解决方案。

使用linq排序网格视图列

最后，经过大量的谷歌搜索和头脑风暴，我找到了解决方案，使用动态Linq。

我抛弃了GenericComparer类，只在排序事件

中编写了以下代码
string sortColumn = e.SortExpression;
    IQueryable<BusinessRisk> sortedList = (from p in this.BusinessRiskList
                                           select new BusinessRisk
                                           {
                                               BusinessRiskText = p.BusinessRiskText,
                                               IsActive = p.IsActive,
                                               Description = p.Description,
                                               BusinessObjective = new BusinessObjective { BusinessObjectiveText = p.BusinessObjective.BusinessObjectiveText }
                                           }).AsQueryable().OrderBy(e.SortExpression);


    this.BusinessRiskList = sortedList.ToList<BusinessRisk>();
    gvBussinessRisks.DataSource = sortedList;
    gvBussinessRisks.DataBind();

这对我来说是完美的。

感谢所有帮助我的人。

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