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每当我加载网格而不添加布局时，父网格加载就好了。但是，每当我添加布局时，将数据绑定到父级时都会引发 NullReferenceException。

public ActionResult Index()
    {
        GridModel grid = GridLoadOnDemandModel();
        grid.ID = "Services";
        grid.LoadOnDemand = true;
        grid.DataSourceUrl = this.Url.Action("BindParent");
        grid.ColumnLayouts[0].DataSourceUrl = this.Url.Action("BindChild");
        return View(grid);
    }

    private GridModel GridLoadOnDemandModel()
    {
        GridModel grid = new GridModel();
        grid.AutoGenerateLayouts = false;
        grid.AutoGenerateColumns = true;
        grid.PrimaryKey = "ID";
        grid.Width = "100%";
        grid.Columns.Add(new GridColumn() { HeaderText = "Service ID", Key = "ID", DataType = "number" });
        grid.Columns.Add(new GridColumn() { HeaderText = "Client ID", Key = "ClientID", DataType = "number" });
        grid.Columns.Add(new GridColumn() { HeaderText = "Package ID", Key = "PackageID", DataType = "number" });

        GridColumnLayoutModel layout = new GridColumnLayoutModel();
        layout.Key = "ServiceHistory";
        layout.ForeignKey = "ID";
        layout.PrimaryKey = "ID";
        layout.AutoGenerateColumns = false;
        layout.Columns.Add(new GridColumn() { HeaderText = "Log ID", Key = "LogID", DataType = "number", Hidden = true });
        layout.Columns.Add(new GridColumn() { HeaderText = "Service ID", Key = "ID", DataType = "number", Hidden = true});
        layout.Columns.Add(new GridColumn() { HeaderText = "Client ID", Key = "ClientID", DataType = "number" });
        layout.Columns.Add(new GridColumn() { HeaderText = "Package ID", Key = "PackageID", DataType = "number" });

        layout.Width = "100%";
        grid.ColumnLayouts.Add(layout);

        return grid;
    }

GetData 方法的 BindParent 方法中引发错误。

    public JsonResult BindParent()
    {
        GridModel model = GridLoadOnDemandModel();
        model.DataSource = GetService().AsQueryable();
        return model.GetData();
    }

    public JsonResult BindChild(string path, string layout)
    {
        GridModel model = GridLoadOnDemandModel();
        model.DataSource = GetServiceLogs().AsQueryable();
        return model.GetData(path, layout);
    }

    private IEnumerable<Service> GetService()
    {
        var services = new List<Service>();

        for (int i = 0; i < 10; i++)
        {
            var service = new Service
            {
                ID = i,
                ClientID = 1,
                PackageID = 1
            };

            services.Add(service);
        }

        return services;
    }

    private IEnumerable<ServiceLog> GetServiceLogs()
    {
        var serviceLogs = new List<ServiceLog>();

        for (int i = 0; i < 10; i++)
        {
            var serviceLog = new ServiceLog
            {
                LogID = i,
                ID = 1,
                ClientID = i,
                PackageID = i
            };

            serviceLogs.Add(serviceLog);
        }

        return serviceLogs;
    } 
public class Service
{
    public int ID { get; set; }
    public int ClientID { get; set; }
    public int PackageID { get; set; }
}

public class ServiceLog
{
    public int LogID { get; set; }
    public int ID { get; set; }
    public int ClientID { get; set; }
    public int PackageID { get; set; }
}

public class Service
{
    public int ID { get; set; }
    public int ClientID { get; set; }
    public int PackageID { get; set; }
}

public class ServiceLog
{
    public int LogID { get; set; }
    public int ID { get; set; }
    public int ClientID { get; set; }
    public int PackageID { get; set; }
}

这是堆栈跟踪：

在 Infragistics.Web.Mvc.GridModel.RenderHierarchicalQueryable(IQueryable queryable) 在 Infragistics.Web.Mvc.GridModel.DataBind() 在 Infragistics.Web.Mvc.GridModel.DataBind() 在 Infragistics.Web.Mvc.GridModel.RenderHierarchicalQueryableRecursive(IQueryable queryable, WrappedGridResponse response, GridModel baseLayout) .Mvc.GridModel.GetData() 在 IgniteUIHTMLEditorExample.Controllers.ServiceHistoryController.BindParent() 在 c:\Users\kyle.wingate\Documents\Visual Studio 2013\Projects\IgniteUIHTMLEditorExample\IgniteUIHTMLEditorExample\Controllers\ServiceHistoryController.cs:line 53 在 lambda_method (Closure , ControllerBase , Object[] ) 在 System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase 控制器, Object[] 参数) 在 System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary2 parameters) at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary2 个参数）在 System.Web.Mvc.Async.AsyncControllerActionInvoker.b__39(IAsyncResult asyncResult, ActionInvocation innerInvokeState) 在 System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult 的 System.Web.Mvc.Async.AsyncControllerActionInvoker.ActionInvocation.InvokeSynchronousActionMethod() 2.CallEndDelegate(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResultBase1.End() at System.Web.Mvc.Async.AsyncResultWrapper.End[TResult](IAsyncResult asyncResult, Object tag) at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) 在 System.Web.Mvc。 Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.b__3d() 在 System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c__DisplayClass46.b__3f()

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1 回答 1

2

在Service类/模型中，您应该有一个以该值命名的属性GridColumnLayoutModel.Key。这是Service该类的外观：

public class Service
{
    public int ID { get; set; }
    public int ClientID { get; set; }
    public int PackageID { get; set; }
    public IEnumerable<ServiceLog>  ServiceHistory { get; set; }
}

此更改将解决NullReferenceException，但您需要进行更多更改才能使您的示例按预期运行。

您还应该正确配置GridColumnLayoutModel.PrimaryKeyand GridColumnLayoutModel.ForeignKey，因为GridModel.GetData它们依赖于它们来提取/过滤正确的子记录。我猜在您的情况下，ServiceHistory布局的配置应该如下所示：

//… code omitted
layout.ForeignKey = "ID";
layout.PrimaryKey = "LogID";
// … code omitted

通过此更改，该方法将按类中的属性GridModel.GetData过滤数据。IDServiceLog

您可能需要更改GetServiceLogs方法以生成不同的ID，因为现在它只会返回数据ServicewithID = 1

于 2016-01-14T12:16:31.193 回答