Сетка данных Silverlight с комбинированными списками - выбранный элемент не отображается - PullRequest
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Сетка данных Silverlight с комбинированными списками - выбранный элемент не отображается

1 голос
/ 14 апреля 2011

У меня проблема с использованием выпадающих списков в сетке данных Silverlight, оба из которых связаны с DataContext, который, в свою очередь, использует RIA для извлечения данных из базы данных.

Проблема у меня возникает, когда вы выбираетезначение в поле со списком и щелкните ячейку, а не ячейка, отображающая вновь выбранное значение, ячейка отображается как пустая.Однако - это происходит только в том случае, если вы выбираете значение, которое еще не было выбрано в другой ячейке таблицы данных!Выбор уникального значения приводит к тому, что в окне отображается пустое

Мой код выглядит следующим образом: 

<navigation:Page x:Class="Chemical_Management_System.EditPermissions" 
       xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
       xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
       xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
       mc:Ignorable="d"
       xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"

       d:DesignWidth="640" d:DesignHeight="480"
       Title="EditPermissions Page" Width="640" HorizontalAlignment="Center" 
             xmlns:riaControls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.DomainServices" 
             xmlns:my="clr-namespace:Chemical_Management_System.Web" 
             xmlns:myn="clr-namespace:Chemical_Management_System" 
             xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk">



<Grid x:Name="LayoutRoot">
    <Border BorderBrush="Silver" BorderThickness="1" Height="45" HorizontalAlignment="Left" Margin="10,10,0,0" Name="Border1" Style="{StaticResource HeaderBackground}" VerticalAlignment="Top" Width="618">
        <TextBlock Height="23" Name="TextBlock21" Style="{StaticResource HeaderText}" Text="Edit Permissions" />
    </Border>
    <riaControls:DomainDataSource AutoLoad="True" d:DesignData="{d:DesignInstance my:Permissions, CreateList=true}" Height="0" Name="PermissionsDomainDataSource" QueryName="GetPermissionsQuery" SubmittedChanges="OnSubmitChanges"  Width="0">
        <riaControls:DomainDataSource.DomainContext>
            <my:DataContext />
        </riaControls:DomainDataSource.DomainContext>
    </riaControls:DomainDataSource>

    <riaControls:DomainDataSource AutoLoad="True" d:DesignData="{d:DesignInstance my:PermissionLookups, CreateList=true}" Height="0" Name="PermissionLookupsDomainDataSource" QueryName="GetPermissionLookupsQuery" Width="0">
        <riaControls:DomainDataSource.DomainContext>
            <my:DataContext />
        </riaControls:DomainDataSource.DomainContext>
    </riaControls:DomainDataSource>

    <riaControls:DomainDataSource AutoLoad="True" d:DesignData="{d:DesignInstance my:Users, CreateList=true}" Height="0" Name="UsersDomainDataSource" QueryName="GetUsersQuery" Width="0">
        <riaControls:DomainDataSource.DomainContext>
            <my:DataContext />
        </riaControls:DomainDataSource.DomainContext>
    </riaControls:DomainDataSource>

    <Button Content="Apply" Height="23" HorizontalAlignment="Left" Margin="553,445,0,0" Name="btnApply" VerticalAlignment="Top" Width="75" />
    <sdk:DataGrid AutoGenerateColumns="False" Height="378" HorizontalAlignment="Left" ItemsSource="{Binding ElementName=PermissionsDomainDataSource, Path=Data}" Margin="12,61,0,0" Name="PermissionsDataGrid" RowDetailsVisibilityMode="VisibleWhenSelected" VerticalAlignment="Top" Width="615">
        <sdk:DataGrid.Columns>

            <sdk:DataGridTemplateColumn Header="User" MinWidth="190">
                <sdk:DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding User.Name}" Padding="5,0,0,0" />
                    </DataTemplate>
                </sdk:DataGridTemplateColumn.CellTemplate>
                <sdk:DataGridTemplateColumn.CellEditingTemplate>
                    <DataTemplate>
                        <ComboBox ItemsSource="{Binding UsersDomainDataSource}" 

                                  Loaded="ComboBoxUsers_Loaded"
                                  SelectionChanged="UsersComboBox_SelectionChanged"
                              >
                            <ComboBox.ItemTemplate>
                                <DataTemplate>
                                    <TextBlock Text="{Binding Name}" />
                                </DataTemplate>
                            </ComboBox.ItemTemplate>

                        </ComboBox>

                    </DataTemplate>
                </sdk:DataGridTemplateColumn.CellEditingTemplate>
            </sdk:DataGridTemplateColumn>
            <sdk:DataGridTemplateColumn Header="Permission" MinWidth="175">
                <sdk:DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding PermissionLookup.Description}" />
                    </DataTemplate>
                </sdk:DataGridTemplateColumn.CellTemplate>
                <sdk:DataGridTemplateColumn.CellEditingTemplate>
                    <DataTemplate>
                        <ComboBox ItemsSource="{Binding PermissionLookupsDomainDataSource}" 

                                  Loaded="ComboBox_Loaded"
                                  SelectionChanged="PermissionLookupComboBox_SelectionChanged"
                              >
                            <ComboBox.ItemTemplate>
                                <DataTemplate>
                                    <TextBlock Text="{Binding Description}" />
                                </DataTemplate>
                            </ComboBox.ItemTemplate>

                        </ComboBox>

                    </DataTemplate>
                </sdk:DataGridTemplateColumn.CellEditingTemplate>
            </sdk:DataGridTemplateColumn>
            <sdk:DataGridTextColumn x:Name="DescriptionColumn" Binding="{Binding Path=Description}" Header="Description" MinWidth="245" />

        </sdk:DataGrid.Columns>
    </sdk:DataGrid>
    <Button Content="New" Height="23" HorizontalAlignment="Left" Margin="12,445,0,0" Name="btnNew" VerticalAlignment="Top" Width="75" />
    <Button Content="Delete" Height="23" HorizontalAlignment="Left" Margin="93,445,0,0" Name="btnDelete" VerticalAlignment="Top" Width="75" />
    <Button Content="Cancel" Height="23" HorizontalAlignment="Left" Margin="472,445,0,0" Name="btnCancel" VerticalAlignment="Top" Width="75" />
</Grid>


Partial Public Class EditPermissions
Inherits Page

Dim Context As New Web.DataContext()
Dim user As New CurrentUser()

Public Sub New()
    InitializeComponent()

    AddHandler user.userLoadedCompleted, AddressOf userLoaded
End Sub

'Executes when the user navigates to this page.
Protected Overrides Sub OnNavigatedTo(ByVal e As System.Windows.Navigation.NavigationEventArgs)

End Sub

Private Sub userLoaded()
    If user.permissionCheck("Admin") = False Then
        MessageBox.Show("You do not have permission to access this page")
        NavigationService.Navigate(New Uri("/Home", UriKind.Relative))
    End If
End Sub

Private Sub PermissionsDomainDataSource_LoadedData(ByVal sender As System.Object, ByVal e As System.Windows.Controls.LoadedDataEventArgs) Handles PermissionsDomainDataSource.LoadedData

    If e.HasError Then
        System.Windows.MessageBox.Show(e.Error.ToString, "Load Error", System.Windows.MessageBoxButton.OK)
        e.MarkErrorAsHandled()
    End If
End Sub


Private Sub PermissionLookupsDomainDataSource_LoadedData(ByVal sender As System.Object, ByVal e As System.Windows.Controls.LoadedDataEventArgs) Handles PermissionLookupsDomainDataSource.LoadedData

    If e.HasError Then
        System.Windows.MessageBox.Show(e.Error.ToString, "Load Error", System.Windows.MessageBoxButton.OK)
        e.MarkErrorAsHandled()
    End If
End Sub

Private Sub ComboBox_Loaded(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)
    ' set combobox items source from wherever you want
    Dim combo As ComboBox = sender
    combo.ItemsSource = Me.PermissionLookupsDomainDataSource.DataView
End Sub

Private Sub ComboBoxUsers_Loaded(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)
    ' set combobox items source from wherever you want
    Dim combo As ComboBox = sender
    combo.ItemsSource = Me.UsersDomainDataSource.DataView
End Sub

Private Sub btnApply_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles btnApply.Click
    Me.PermissionsDomainDataSource.SubmitChanges()
    NavigationService.Navigate(New Uri("/AdminHome", UriKind.Relative))
End Sub

Private Sub btnDelete_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles btnDelete.Click
    If PermissionsDataGrid.SelectedItem IsNot Nothing Then
        Dim selected As Web.Permissions = PermissionsDataGrid.SelectedItem
        Me.PermissionsDomainDataSource.DataView.Remove(selected)
    Else
        MessageBox.Show("Please select a permission entry to delete")
    End If

End Sub

Private Sub btnNew_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles btnNew.Click
    Dim permission As New Web.Permissions
    Me.PermissionsDomainDataSource.DataView.Add(permission)
End Sub

Private Sub btnCancel_Click(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles btnCancel.Click
    Me.PermissionsDomainDataSource.RejectChanges()
    NavigationService.Navigate(New Uri("/AdminHome", UriKind.Relative))
End Sub

Private Sub OnSubmitChanges(ByVal sender As Object, ByVal e As SubmittedChangesEventArgs)
    If (e.HasError) Then
        MessageBox.Show("Error: " + e.Error.ToString)
    End If

End Sub

Private Sub UsersComboBox_SelectionChanged(ByVal sender As System.Object, ByVal e As System.Windows.Controls.SelectionChangedEventArgs)

    Dim permission As Web.Permissions = PermissionsDataGrid.SelectedItem
    Dim selected As ComboBox = sender
    Dim user As Web.Users = selected.SelectedItem

    permission.UserID = user.ID
    selected.UpdateLayout()
End Sub

Private Sub PermissionLookupComboBox_SelectionChanged(ByVal sender As System.Object, ByVal e As System.Windows.Controls.SelectionChangedEventArgs)

    Dim permission As Web.Permissions = PermissionsDataGrid.SelectedItem
    Dim selected As ComboBox = sender
    Dim permissionLookup As Web.PermissionLookups = selected.SelectedItem

    permission.PermissionID = permissionLookup.ID

End Sub
End Class

Ответы [ 2 ]

0 голосов
/ 14 апреля 2011

Вы знаете, я сидел с этой проблемой целую вечность и не мог найти решение.Во-вторых, я публикую это онлайн ... меня осенило.Я ненавижу, когда это происходит.В любом случае, решение заключается в следующем.

Поскольку база данных и, следовательно, объекты данных построены со строго типизированными ссылками, вы можете получить доступ к пользователю, указанному в любой данной группе разрешений, с помощью Permission.User.Property.Вы также можете назначить этому Permission.User установить ссылки тоже.

Хотя я пытался сделать это ранее, используя DataDomainSources, он всегда выдавал ошибку, сообщая, что объект уже связан с другим DataDomainSources.это связано с тем, что у вас есть один DataDomainSources для разрешений и один для пользователей.

Однако это ограничение не существует при использовании DataContext, поскольку и пользователи, и разрешения существуют в одном и том же DataContext.

Поэтому я переписал код следующим образом: 

<navigation:Page x:Class="Chemical_Management_System.EditPermissions" 
       xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
       xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
       xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
       xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
       mc:Ignorable="d"
       xmlns:navigation="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Navigation"

       d:DesignWidth="640" d:DesignHeight="480"
       Title="EditPermissions Page" Width="640" HorizontalAlignment="Center" 
             xmlns:riaControls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.DomainServices" 
             xmlns:my="clr-namespace:Chemical_Management_System.Web" 
             xmlns:myn="clr-namespace:Chemical_Management_System" 
             xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk">



<Grid x:Name="LayoutRoot" >
    <Border BorderBrush="Silver" BorderThickness="1" Height="45" HorizontalAlignment="Left" Margin="10,10,0,0" Name="Border1" Style="{StaticResource HeaderBackground}" VerticalAlignment="Top" Width="618">
        <TextBlock Height="23" Name="TextBlock21" Style="{StaticResource HeaderText}" Text="Edit Permissions" />
    </Border>


    <Button Content="Apply" Height="23" HorizontalAlignment="Left" Margin="553,445,0,0" Name="btnApply" VerticalAlignment="Top" Width="75" />
    <Button Content="New" Height="23" HorizontalAlignment="Left" Margin="12,445,0,0" Name="btnNew" VerticalAlignment="Top" Width="75" />
    <Button Content="Delete" Height="23" HorizontalAlignment="Left" Margin="93,445,0,0" Name="btnDelete" VerticalAlignment="Top" Width="75" />
    <Button Content="Cancel" Height="23" HorizontalAlignment="Left" Margin="472,445,0,0" Name="btnCancel" VerticalAlignment="Top" Width="75" />
    <sdk:DataGrid AutoGenerateColumns="False" Height="364" HorizontalAlignment="Left" Margin="10,75,0,0" Name="dataGrid" VerticalAlignment="Top" Width="618" DataContext="dataContext.Permissions">
        <sdk:DataGrid.Columns>
            <sdk:DataGridTextColumn x:Name="DescriptionColumn" Binding="{Binding Path=Description}" Header="Description" MinWidth="245" />

            <sdk:DataGridTemplateColumn Header="User" MinWidth="190">
                <sdk:DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding User.Name}" Padding="5,0,0,0" />
                    </DataTemplate>
                </sdk:DataGridTemplateColumn.CellTemplate>

                <sdk:DataGridTemplateColumn.CellEditingTemplate>
                    <DataTemplate>
                        <ComboBox Loaded="UserComboBox_Loaded" SelectionChanged="UserComboBox_SelectionChanged">
                            <ComboBox.ItemTemplate>
                                <DataTemplate>
                                    <TextBlock Text="{Binding Name}" />
                                </DataTemplate>
                            </ComboBox.ItemTemplate>
                        </ComboBox>
                    </DataTemplate>
                </sdk:DataGridTemplateColumn.CellEditingTemplate>


            </sdk:DataGridTemplateColumn>

            <sdk:DataGridTemplateColumn Header="Permission" MinWidth="190">
                <sdk:DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <TextBlock Text="{Binding PermissionLookup.Description}" Padding="5,0,0,0" />
                    </DataTemplate>
                </sdk:DataGridTemplateColumn.CellTemplate>

                <sdk:DataGridTemplateColumn.CellEditingTemplate>
                    <DataTemplate>
                        <ComboBox Loaded="PermissionComboBox_Loaded" SelectionChanged="PermissionComboBox_SelectionChanged">
                            <ComboBox.ItemTemplate>
                                <DataTemplate>
                                    <TextBlock Text="{Binding Description}" />
                                </DataTemplate>
                            </ComboBox.ItemTemplate>
                        </ComboBox>
                    </DataTemplate>
                </sdk:DataGridTemplateColumn.CellEditingTemplate>


            </sdk:DataGridTemplateColumn>


        </sdk:DataGrid.Columns>
    </sdk:DataGrid>
</Grid>


Partial Public Class EditPermissions
Inherits Page

Dim Context As New Web.DataContext()
Dim user As New CurrentUser()


Public Sub New()
    InitializeComponent()

    AddHandler user.userLoadedCompleted, AddressOf userLoaded

    Context.Load(Context.GetPermissionsQuery())
    Context.Load(Context.GetUsersQuery())
    Context.Load(Context.GetPermissionLookupsQuery)


    dataGrid.ItemsSource = Context.Permissions


End Sub

'Executes when the user navigates to this page.
Protected Overrides Sub OnNavigatedTo(ByVal e As System.Windows.Navigation.NavigationEventArgs)

End Sub

Private Sub userLoaded()
    If user.permissionCheck("Admin") = False Then
        MessageBox.Show("You do not have permission to access this page")
        NavigationService.Navigate(New Uri("/Home", UriKind.Relative))
    End If
End Sub





Private Sub UserComboBox_Loaded(sender As System.Object, e As System.Windows.RoutedEventArgs)
    Dim combo As ComboBox = sender
    combo.ItemsSource = Context.Users
End Sub

Private Sub UserComboBox_SelectionChanged(sender As System.Object, e As System.Windows.Controls.SelectionChangedEventArgs)
    Dim combo As ComboBox = sender
    Dim user As Web.Users = combo.SelectedItem

    Dim currentPermission As Web.Permissions = dataGrid.SelectedItem
    currentPermission.User = user

End Sub


Private Sub PermissionComboBox_Loaded(sender As System.Object, e As System.Windows.RoutedEventArgs)
    Dim combo As ComboBox = sender
    combo.ItemsSource = Context.PermissionLookups
End Sub

Private Sub PermissionComboBox_SelectionChanged(sender As System.Object, e As System.Windows.Controls.SelectionChangedEventArgs)
    Dim combo As ComboBox = sender
    Dim permissionLookup As Web.PermissionLookups = combo.SelectedItem

    Dim currentPermission As Web.Permissions = dataGrid.SelectedItem
    currentPermission.PermissionLookup = permissionLookup

End Sub

Private Sub btnApply_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles btnApply.Click
    Context.SubmitChanges()
End Sub

Private Sub btnNew_Click(sender As System.Object, e As System.Windows.RoutedEventArgs) Handles btnNew.Click
    Dim newpermission As New Web.Permissions
    Context.Permissions.Add(newpermission)
End Sub


End Class
0 голосов
/ 14 апреля 2011
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