Question

我有以下xaml：

<Window x:Class="level4.Workers"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:level4"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        Title="Workers" Height="300" Width="400">
    <Window.Resources>
        <!--The workers DataBase-->
        <ObjectDataProvider x:Key="WorkersDataProvider" ObjectType="{x:Type local:WorkerAdapter}"/>
        <ObjectDataProvider x:Key="Workers" ObjectInstance="{StaticResource WorkersDataProvider}" MethodName="getWorkers"/>

        <!--The person data provider-->
        <ObjectDataProvider x:Key="PersonDataProvider" ObjectType="{x:Type local:PersonAdapter}" />
        <ObjectDataProvider x:Key="Person" ObjectInstance="{StaticResource PersonDataProvider}" MethodName="getPersonByID">
            <ObjectDataProvider.MethodParameters>
                <sys:Int32>0</sys:Int32>
            </ObjectDataProvider.MethodParameters>
        </ObjectDataProvider>

    </Window.Resources>
    <Grid DataContext="{Binding Source={StaticResource Workers}}">
        <DataGrid ItemsSource="{Binding}" AutoGenerateColumns="False" SelectionChanged="WorkersSelectionChanged">
            <DataGrid.Columns>
                <DataGridTextColumn Header="workers ID" Binding="{Binding WID}" />
                <DataGridTextColumn Header="salary (k/m)" Binding="{Binding SALARY}" />
                <DataGridTextColumn Header="worker's rank" Binding="{Binding WRANK}" />
                <DataGridTextColumn Header="Seniority" Binding="{Binding SENIORITY}" />
                <DataGridHyperlinkColumn Header="works in branch:" Binding="{Binding BRANCHNUM}"  />
            </DataGrid.Columns>
            <DataGrid.RowDetailsTemplate>
                <DataTemplate>
                    <Grid DataContext="{Binding Source={StaticResource Person}}">
                        <DataGrid ItemsSource="{Binding Source={StaticResource Person}}" CanUserAddRows="False" IsReadOnly="True" HeadersVisibility="None" AutoGenerateColumns="True" />
                    </Grid>
                </DataTemplate>
            </DataGrid.RowDetailsTemplate>
        </DataGrid>
    </Grid>
</Window>

函数WorkersSelectionChanged如下：

 private void WorkersSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            DataGrid grid = sender as DataGrid;
            ObjectDataProvider PersonProvider = this.FindResource("Person") as ObjectDataProvider;
            System.Data.DataRowView drv = grid.SelectedItem as System.Data.DataRowView;
            PersonProvider.MethodParameters[0] = Int32.Parse(drv["PID"].ToString());

        }

函数getPersonByID如下：

public DataView getPersonByID(Int32 PID)
        {
            DataRow datarow = dt.Select(String.Format("PID = {0}", PID)).FirstOrDefault();
            DataTable ret = new DataTable();
            ret.ImportRow(datarow);
            return ret.DefaultView;
        }

（dt的类型为DataTable）

问题：工作人员表正确显示，但行详细信息始终为空表。我检查了调试器，每次选择一行时调用函数getPersonByID，使用正确的PID值，DataTable ret有一些行，但显示的表仍然是空的。

我哪里出错了？

我正在使用VS2012，.NET framework 4.5

Answer 1

总结评论，您的新DataTable没有列，因此不使用DataTable.Clone创建新DataTable

克隆DataTable的结构，包括所有DataTable模式和约束。

所以在你的情况下替换

DataTable ret = new DataTable();

带

DataTable ret = dt.Clone();

显示的行详细信息始终为空

1 个答案: