Question

我很难让ObjectDataProvider使用方法参数。现在使用以下代码，我可以在XAML visual studio设计器中查看数据，但是一旦我尝试刷新ObjectDataProvider，我的数据就会消失。我已经设置了一个带有五个参数的对象数据提供程序，虽然它们没有传递给数据集查询，我只是想看看我是否可以先传递这些参数。我在底部运行filter方法刷新OBJDataProvider并且我的datagrid变为空白？

我的两个ObjectDataProviders

<ObjectDataProvider x:Key="LogDataProvider" ObjectType="{x:Type local:LogDataProvider}"/>

<ObjectDataProvider x:Key="siteListContains" MethodName="GetLog2" ObjectType="{x:Type local:LogDataProvider}">
   <ObjectDataProvider.MethodParameters>
      <s:String>Red</s:String>
      <s:DateTime>12:14:24</s:DateTime>
      <s:DateTime>2008-01-01</s:DateTime>
      <s:DateTime>12:12:12</s:DateTime>
      <s:DateTime>2008-01-01</s:DateTime>
   </ObjectDataProvider.MethodParameters>
</ObjectDataProvider>

数据网格及其与对象数据提供程序的绑定

<dg:DataGrid Name="log_datagrid" Height="230" VerticalAlignment="Stretch" 
DataContext="{Binding Source={StaticResource siteListContains}}" 
ItemsSource="{Binding}" AutoGenerateColumns="True"/>

我的LogDataProvider类

public class LogDataProvider
{
   private eventlogTableAdapter adapter;
   DataSet1 dataset;

   public LogDataProvider()
   {
      dataset = new DataSet1();
      adapter = new eventlogTableAdapter();
   }

   public DataView GetLog2(string sitestr, DateTime fromtimestr, DateTime fromdatestr, DateTime totimestr, DateTime todatestr)
   {
      adapter.Fill(dataset.eventlog);
      return dataset.eventlog.DefaultView;
   }
}

这里我遇到了问题，当我将sitestr传递给MethodParameter [0]时，它会立即跳转到LogDataProvider的GetLog2方法，而不会接收其余的参数......然后我的数据网格变为空白： - （

private void filter_btn_Click(object sender, RoutedEventArgs e)
{
   ObjectDataProvider sitelist_dataobj = this.FindResource("siteListContains") as ObjectDataProvider;
   sitelist_dataobj.MethodParameters[0] = sitestr.Text.ToString();
   sitelist_dataobj.MethodParameters[1] = from_timePicker.SelectedTime;
   sitelist_dataobj.MethodParameters[2] = from_datepicker.SelectedDate;
   sitelist_dataobj.MethodParameters[3] = to_timePicker.SelectedTime;
   sitelist_dataobj.MethodParameters[4] = to_datepicker.SelectedDate;

   sitelist_dataobj.Refresh();
}

Answer 1

每次更新任何参数时都应调用Refresh。如果你要设置多个，你应该使用DeferRefresh让它等到你完成：

private void filter_btn_Click(object sender, RoutedEventArgs e)
{
    ObjectDataProvider sitelist_dataobj = this.FindResource("siteListContains") as ObjectDataProvider;
    using (sitelist_dataobj.DeferRefresh())
    {
        sitelist_dataobj.MethodParameters[0] = sitestr.Text.ToString();
        sitelist_dataobj.MethodParameters[1] = from_timePicker.SelectedTime;
        sitelist_dataobj.MethodParameters[2] = from_datepicker.SelectedDate;
        sitelist_dataobj.MethodParameters[3] = to_timePicker.SelectedTime;
        sitelist_dataobj.MethodParameters[4] = to_datepicker.SelectedDate;
    }
}

使用MethodParameters无法正确刷新WPF Datagrid

1 个答案: