在过去几天搜索之后,我正式陷入困境.我正在研究将对象绑定到Telerik MVC 3 Grid,但问题是它需要动态创建的列(不是自动生成的).其中三列是已知的,其他列是未知的,这是棘手的部分.基本上,它可以像这些例子：
KnownColumn1 | KnownColumn2 | UnknownColumn1 | KnownColumn3
KnownColumn1 | KnownColumn2 | UnknownColumn1 | UnknownColumn2 | UnknownColumn3 | KnownColumn3
等等
因为我将未知列放在列表中(我也尝试过字典,所以我可以获取列名),这在绑定时对我来说很复杂.我的代码如下：
模型(可以有零到几百行,但是这个模型在List类型的视图模型中,也可以有0到20个动态添加的列)
public class VendorPaymentsGLAccount
{
public string GeneralLedgerAccountNumber { get; set; }
public string GeneralLedgerAccountName { get; set; }
public string DisplayName { get { return string.Format("{0} - {1}",GeneralLedgerAccountNumber,GeneralLedgerAccountName); } }
public Dictionary<string,double> MonthAmount { get; set; }
public double Total { get { return MonthAmount.Sum(x => x.Value); } }
public List<string> Columns { get; set; }
public List<double> Amounts { get; set; }
public VendorPaymentsGLAccount() { }
}
查看(注释掉的部分试图使用字典)
<fieldset>
<legend>General Ledger Account Spend History</legend>
@if (Model.VendorPaymentsGLAccounts != null)
{
<br />
@(Html.Telerik().Grid(Model.VendorPaymentsGLAccounts)
.Name("Grid")
.Columns(columns =>
{
columns.Bound(gl => gl.DisplayName).Title("General Ledger Account").Width(200).Filterable(false).Sortable(false);
//foreach (var month in Model.VendorPaymentsGLAccounts[0].MonthAmount)
//{
// //columns.Bound(gl => gl.MonthAmount[month.Key.ToString()].ToString()).Title(month.Key.ToString()).Width(100).Filterable(false).Sortable(false);
// //columns.Template(v => Html.ActionLink(v.VoucherID,"VoucherSummary",new { id = v.VoucherID,bu = v.BusinessUnitID,dtt = v.InvoiceDate.Ticks })).Title("Voucher").Width(100);
// columns.Template(gl => Html.ActionLink(gl.MonthAmount[month.Key.ToString()].ToString(),"VoucherSummary")).Title(month.Key.ToString()).Width(100);
//}
for (int i = 1; i <= (Model.VendorPaymentsGLAccounts[0].Columns.Count() - 1); i++)
{
string colTemp = Model.VendorPaymentsGLAccounts[0].Columns[i - 1];
columns.Template(gl => gl.Amounts[i - 1]).Title(colTemp).Width(100);
}
columns.Template(gl => String.Format("{0:C}",gl.Total)).Title("Total");
})
.Sortable()
.Pageable()
.Filterable()
.Footer(true))
}
else
{
<br />
@:There are no records that match your selected criteria.
}
</fieldset>
使用字典方法,我能够使用正确的标题文本正确生成列,但列的值(在我的测试中只有2列)是相同的.有人能帮忙吗？这似乎是一个古怪的问题.只是想弄清楚如何正确地做到这一点.
解决方法
使用带有Telerik网格控件的动态定义列可能很棘手.但在你的情况下,它主要是一个典型的闭包陷阱.
在以下循环中,编译器将绑定gl =>的每个实例. gl.Amounts [i – 1]到变量i并稍后评估它：
for (int i = 1; i <= (Model.VendorPaymentsGLAccounts[0].Columns.Count() - 1); i++)
{
string colTemp = Model.VendorPaymentsGLAccounts[0].Columns[i - 1];
columns.Template(gl => gl.Amounts[i - 1]).Title(colTemp).Width(100);
}
实际上,它是在循环结束后进行评估的.所以我将始终拥有导致循环完成的值.
修复是使用临时变量：
for (int i = 1; i <= (Model.VendorPaymentsGLAccounts[0].Columns.Count() - 1); i++)
{
string colTemp = Model.VendorPaymentsGLAccounts[0].Columns[i - 1];
int columnIndex = i - 1;
columns.Template(gl => gl.Amounts[columnIndex]).Title(colTemp).Width(100);
}
