Silverlight DataGrid控件 - 选择已更改的事件会干扰排序 [英] Silverlight- DataGrid control - Selection Changed event interfering with sorting

问题描述

我目前正在使用Silverlight（Beta 2）Datagrid控件。在我连线SelectionChanged事件之前，网格可以通过点击标题进行排序。现在，当点击网格时，当我点击要排序的标题时，它会触发SelectionChanged事件。有没有办法？

I'm currently playing with the Silverlight(Beta 2) Datagrid control. Before I wired up the SelectionChanged event, the grid would sort perfectly by clicking on the header. Now, when the grid is clicked, it will fire the SelectionChanged event when I click the header to sort. Is there any way around this?

在一个半相关的主题中，当我点击已经选择的项目时，我希望SelectionChanged事件触发（这样我可以弹出一个允许用户编辑所选值的弹出窗口。现在，您必须单击不同的值，然后返回到您想要的值才能弹出。还有另一种方式吗？

In a semi-related topic, I'd like to have the SelectionChanged event fire when I click on an already selected item (so that I can have a pop-up occur to allow the user to edit the selected value). Right now, you have to click on a different value and then back to the value you wanted in order for it to pop up. Is there another way?

包含的是我的代码。

页面：

<UserControl x:Class="WebServicesApp.Page"
xmlns="http://schemas.microsoft.com/client/2007" 
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
xmlns:data="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data"
Width="1280" Height="1024" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d">
<Grid x:Name="LayoutRoot" Background="White">
    <Grid.RowDefinitions>
        <RowDefinition />
        <RowDefinition />
    </Grid.RowDefinitions>
    <StackPanel Grid.Row="0" x:Name="OurStack" Orientation="Vertical" Margin="5,5,5,5">
        <ContentControl VerticalAlignment="Center" HorizontalAlignment="Center">
            <StackPanel x:Name="SearchStackPanel" Orientation="Horizontal" Margin="5,5,5,5">
                <TextBlock x:Name="SearchEmail" HorizontalAlignment="Stretch" VerticalAlignment="Center" Text="Email Address:" Margin="5,5,5,5" />
                <TextBox x:Name="InputText" HorizontalAlignment="Stretch" VerticalAlignment="Center" Width="150" Height="Auto" Margin="5,5,5,5"/>
                <Button x:Name="SearchButton" Content="Search" Click="CallServiceButton_Click" HorizontalAlignment="Center" VerticalAlignment="Center" Width="75" Height="Auto" Background="#FFAFAFAF" Margin="5,5,5,5"/>
            </StackPanel>               
        </ContentControl>
<Grid x:Name="DisplayRoot" Background="White" ShowGridLines="True"
                HorizontalAlignment="Center" VerticalAlignment="Center" MaxHeight="300" MinHeight="100" MaxWidth="800" MinWidth="200"
                ScrollViewer.HorizontalScrollBarVisibility="Visible" ScrollViewer.VerticalScrollBarVisibility="Visible">
<data:DataGrid ItemsSource="{Binding ''}" CanUserReorderColumns="False" CanUserResizeColumns="False"  
                           AutoGenerateColumns="False" AlternatingRowBackground="#FFAFAFAF" SelectionMode="Single" 
                           HorizontalAlignment="Center"  VerticalAlignment="Center" Margin="5,5,5,5" x:Name="IncidentGrid" SelectionChanged="IncidentGrid_SelectionChanged">
                <data:DataGrid.Columns>
                    <data:DataGridTextColumn DisplayMemberBinding="{Binding Address}" Header="Email Address" IsReadOnly="True"  /> <!--Width="150"-->
                    <data:DataGridTextColumn DisplayMemberBinding="{Binding whereClause}" Header="Where Clause" IsReadOnly="True"  /> <!--Width="500"--> 
                    <data:DataGridTextColumn DisplayMemberBinding="{Binding Enabled}" Header="Enabled" IsReadOnly="True"  />
</data:DataGrid.Columns>
            </data:DataGrid>
        </Grid>
    </StackPanel>
    <Grid x:Name="EditPersonPopupGrid" Visibility="Collapsed">
        <Rectangle HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Opacity="0.765" Fill="#FF8A8A8A" />
        <Border CornerRadius="30" Background="#FF2D1DCC" Width="700" Height="400" HorizontalAlignment="Center" VerticalAlignment="Center" BorderThickness="1,1,1,1" BorderBrush="#FF000000">
            <StackPanel x:Name="EditPersonStackPanel" Orientation="Vertical" Background="White" HorizontalAlignment="Center" VerticalAlignment="Center" Width="650" >
                <ContentControl>
                    <StackPanel x:Name="EmailEditStackPanel" Orientation="Horizontal">
                        <TextBlock Text="Email Address:" Width="200" Margin="5,0,5,0" />
                        <TextBox x:Name="EmailPopupTextBox" Width="200" />
                    </StackPanel>
                </ContentControl>
                <ContentControl>
                    <StackPanel x:Name="AppliesToDropdownStackPanel" Orientation="Horizontal" Margin="2,2,2,0">
                        <TextBlock Text="Don't send when update was done by:" />
                        <StackPanel Orientation="Vertical" MaxHeight="275" MaxWidth="350" >
                            <TextBlock x:Name="SelectedItemTextBlock" TextAlignment="Right" Width="200" Margin="5,0,5,0" />
                            <Grid x:Name="UserDropDownGrid" MaxHeight="75" MaxWidth="200" Visibility="Collapsed" ScrollViewer.VerticalScrollBarVisibility="Visible" ScrollViewer.HorizontalScrollBarVisibility="Hidden" >
                                <Rectangle Fill="White" />
                                <Border Background="White">
                                    <ListBox x:Name="UsersListBox" SelectionChanged="UsersListBox_SelectionChanged" ItemsSource="{Binding UserID}" />
                                </Border>                                       
                            </Grid>
                        </StackPanel>
                        <Button x:Name="DropDownButton" Click="DropDownButton_Click" VerticalAlignment="Top" Width="25" Height="25">
                            <Path Height="10" Width="10" Fill="#FF000000" Stretch="Fill" Stroke="#FF000000" Data="M514.66669,354 L542.16669,354 L527.74988,368.41684 z" HorizontalAlignment="Center" VerticalAlignment="Center" Margin="1,1,1,1"/>
                        </Button>
                    </StackPanel>
                </ContentControl>
                <TextBlock Text="Where Clause Condition:" />
                <TextBox x:Name="WhereClauseTextBox" Height="200" Width="800" AcceptsReturn="True" TextWrapping="Wrap" />
                <ContentControl>
                    <StackPanel Orientation="Vertical">
                        <StackPanel Orientation="Horizontal">
                            <Button x:Name="TestConditionButton" Content="Test Condition" Margin="5,5,5,5" Click="TestConditionButton_Click" />
                            <Button x:Name="Save" Content="Save" HorizontalAlignment="Right" Margin="5,5,5,5" Click="Save_Click" />
                            <Button x:Name="Cancel" Content="Cancel" HorizontalAlignment="Right" Margin="5,5,5,5" Click="Cancel_Click" />                       
                        </StackPanel>   
                        <TextBlock x:Name="TestContitionResults" Visibility="Collapsed" />
                    </StackPanel>
                </ContentControl>
            </StackPanel>               
        </Border>               
    </Grid>     
</Grid>

网格的选择被更改：

Private Sub IncidentGrid_SelectionChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)

    If mFirstTime Then
        mFirstTime = False
    Else
        Dim data As SimpleASMX.EMailMonitor = CType(IncidentGrid.SelectedItem, SimpleASMX.EMailMonitor)
        Dim selectedGridItem As SimpleASMX.EMailMonitor = Nothing
        If IncidentGrid.SelectedItem IsNot Nothing Then
            selectedGridItem = CType(IncidentGrid.SelectedItem, SimpleASMX.EMailMonitor)
            EmailPopupTextBox.Text = selectedGridItem.Address
            SelectedItemTextBlock.Text = selectedGridItem.AppliesToUserID
            WhereClauseTextBox.Text = selectedGridItem.whereClause
            IncidentGrid.SelectedIndex = mEmailMonitorData.IndexOf(selectedGridItem)
        End If
        If IncidentGrid.SelectedIndex > -1 Then
            EditPersonPopupGrid.Visibility = Windows.Visibility.Visible
        Else
            EditPersonPopupGrid.Visibility = Windows.Visibility.Collapsed
        End If
    End If
End Sub

对不起，如果我的代码是恶毒的，我还在学习Silverlight。

Sorry if my code is atrocious, I'm still learning Silverlight.

推荐答案

看起来像是一个Silverlight错误给我。我刚刚尝试过，结果发生的是，当您点击列标题时， SelectionChanged 事件会触发两次，更糟糕的是，所选项目的索引不保持同步当前选择的项目。

That looks like a Silverlight bug to me. I've just tried it and what's happening on my end is that the SelectionChanged event fires twice when you click the column header and to make matters worse, the index of the selected item doesn't stay synched with the currently selected item.

我建议您使用SelectionChanged第一次触发的知识，datagrid的 SelectedItem的值属性将为 null

I'd suggest you work your way around it by using the knowledge that the first time SelectionChanged fires, the value of the datagrid's SelectedItem property will be null

以下是一些至少与此问题相关的示例代码。 SelectionChanged 逻辑可以在 if 子句中。

Here's some sample code that at least lives with the issue. Your SelectionChanged logic can go in the if clause.

public partial class Page : UserControl
{
    private Person _currentSelectedPerson;

    public Page()
    {
        InitializeComponent();

        List<Person> persons = new List<Person>();
        persons.Add(new Person() { Age = 5, Name = "Tom" });
        persons.Add(new Person() { Age = 3, Name = "Lisa" });
        persons.Add(new Person() { Age = 4, Name = "Sam" });

        dg.ItemsSource = persons;
    }       

    private void SelectionChanged(object sender, EventArgs e)
    {
        DataGrid grid = sender as DataGrid;
        if (grid.SelectedItem != null)
        {
            _currentSelectedPerson = grid.SelectedItem as Person;
        }
        else
        {
            grid.SelectedItem = _currentSelectedPerson;
        }
    }
 }

public class Person
{
    public string Name { get; set; }
    public int Age { get; set; }
}

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