将嵌套网格视图绑定到绑定在 linq 数据结果上的网格视图时出现投射错误

Question

我有一个父网格视图 (UserTransactionGridView)，我将其与此 linq 查询的输出绑定，其输出如下所示： http://postimage.org/image/1vtpbagck/:

        var recordList = (from CustomersRecord custsRecord in customerRecordContainer orderby custsRecord.DateOfTransaction descending group custsRecord 
                          by new {custsRecord.InvoiceNumber, custsRecord.DateOfTransaction} into intermediateResult 
                          select new {InvoiceNumber = intermediateResult.Key.InvoiceNumber, DateOfTransaction = intermediateResult.Key.DateOfTransaction, TotalAmount = intermediateResult.Sum(custsRecord => custsRecord.TotalAmount)}).ToList();
        UserTransactionGridView.DataSource = recordList;
        UserTransactionGridView.DataBind();  

现在，当数据绑定到父网格视图中的每一行时，我将根据每行发票编号创建一个子网格视图 (gridview2)。我的意思是根据每一行的发票编号，我从数据库中获取软件标题并以这种方式将其绑定到子网格视图。我的意图是有这样的输出：http://postimage.org/image/2lri4f544/。我正在做以下事情来实现这一点：

 protected void UserTransactionGridView_RowDataBound(Object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            GridView gridView2 = (GridView)e.Row.FindControl("gridView2");
            System.Data.DataRowView dr = (System.Data.DataRowView)e.Row.DataItem;
            gridView2.AutoGenerateColumns = true;
            String x = dr[1].ToString();
            softwareTitlesList = SoftwareListRetrieve();
            ArrayList titles = new ArrayList();
            foreach (SoftwareTitles softwareTitle in softwareTitlesList)
            {
                if (softwareTitle.InvoiceNumber.Contains(x))
                    titles.Add(softwareTitle.SoftwareTitle);
            }
            gridView2.DataSource = titles;
            gridView2.DataBind();
            softwareTitlesList.Clear();
        }
    }

但我收到如下错误：

Unable to cast object of type '<>f__AnonymousType3`3[System.String,System.DateTime,System.Decimal]' to type 'System.Data.DataRowView'.

Answer 1

您正在尝试将e.Row.DateItem 转换为DataRowView，我认为这行不通。尝试this example 以供参考。在那篇文章的最后一段代码中，做了类似的事情。