WPF DataGrid问题 [英] Wpf DataGrid issue

问题描述

要重现此问题，请添加用户控件，将其粘贴在下面的xaml中，然后将实例添加到窗口中。最后，将窗口的数据上下文设置为ADummyDataContext的实例（也在下面）

To reproduce this issue, Add a user control, paste in the xaml below and then add an instance to a window. Finally set the window's datacontext to an instance of ADummyDataContext (also below)

首次运行该应用程序时，您应该获得一个网格，其中包含三个类别，每个类别包含一个猫。如果单击底部的两个类别之一，然后单击猫的名称，则会出现蓝色行，仅显示猫的名称。

When you run the application for the first time, you should get a grid with three categories each containing one cat. If you click on either of the bottom two categories and click on a cat name, a blue row will appear showing just the cat's name.

但是，如果单击第一个并单击猫的行，蓝色行将不会出现。
注意：这仅在您首次运行该应用程序时发生。一旦您单击任何其他猫，第一类中的猫就会按预期工作。

However, if you click the first row and click the cat's row, the blue row will not appear. NOTE: This only happens the first time you run the application. As soon as you click on any other cat the cat in the first category will work as expected.

<UserControl x:Class="WpfUserControls.SimpleGridControl"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         Background="#FFE46400">
<Grid Margin="2,2,2,2">
    <Grid.RowDefinitions>
        <RowDefinition Height="26" MaxHeight="26" MinHeight="26" />
        <RowDefinition />
        <RowDefinition Height="26" MaxHeight="26" MinHeight="26" />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition />
    </Grid.ColumnDefinitions>
    <ToolBar Grid.Row="0">
        <Button Content="Button" Name="button1" VerticalAlignment="Center" Width="75" />
        <Button Content="Button" Name="button2" VerticalAlignment="Center" Width="75" />
    </ToolBar>
    <DataGrid CanUserAddRows="False" ItemsSource="{Binding Path=KittensView}"  AutoGenerateColumns="True" Grid.Row="1"  HorizontalAlignment="Stretch" Name="dataGrid1" VerticalAlignment="Stretch">
        <DataGrid.GroupStyle>
            <GroupStyle>
                <GroupStyle.HeaderTemplate>
                    <DataTemplate>
                        <StackPanel>
                            <TextBlock Text="{Binding Path=Name}" />
                        </StackPanel>
                    </DataTemplate>
                </GroupStyle.HeaderTemplate>
                <GroupStyle.ContainerStyle>
                    <Style TargetType="{x:Type GroupItem}">
                        <Setter Property="Template">
                            <Setter.Value>
                                <ControlTemplate TargetType="{x:Type GroupItem}">
                                    <Expander>
                                        <Expander.Header>
                                            <StackPanel Orientation="Horizontal">
                                                <TextBlock Text="{Binding Path=Name}" Margin="0,0,5,0"/>
                                                <TextBlock Text="{Binding Path=ItemCount}"/>
                                                <TextBlock Text=" Items"/>
                                            </StackPanel>
                                        </Expander.Header>
                                        <ItemsPresenter />
                                    </Expander>
                                </ControlTemplate>
                            </Setter.Value>
                        </Setter>
                    </Style>
                </GroupStyle.ContainerStyle>
            </GroupStyle>
        </DataGrid.GroupStyle>
        <DataGrid.RowDetailsTemplate>
            <DataTemplate>
                <StackPanel Background="LightBlue" Orientation="Horizontal" >
                    <!-- <Image Height="32" Width="32" Source="/WpfUserControls;component/cat.png"></Image> -->
                    <TextBlock VerticalAlignment="Center" HorizontalAlignment="Center" Height ="20" Text="{Binding Path=Name}"/>
                </StackPanel>
            </DataTemplate>
        </DataGrid.RowDetailsTemplate>
    </DataGrid>
    <StatusBar Grid.Row="2"></StatusBar>

</Grid>
</UserControl>

这是数据上下文类和Kitten类。

And here is the data context class and a Kitten class.

    public class ADummyDataContext
{
    public List<Kitten> Kittens { get; set; } 

    public ADummyDataContext()
    {
        Kittens = new List<Kitten>
                      {
                          new Kitten {Color = "Orange", Name = "Alfie", Weight=6, Sex="Male"},
                          new Kitten {Color = "Black and White", Name = "Smudge", Weight = 4, Sex="Female"},
                          new Kitten {Color = "Grey", Name = "Charlotte", Weight = 5, Sex="Female"}
                      };
        KittensView = new ListCollectionView(Kittens);
        KittensView.GroupDescriptions.Add(new PropertyGroupDescription("Weight"));
    }

    public ListCollectionView KittensView { get; set; }
}

public class Kitten
{
    public string Name { get; set; }
    public string Color { get; set; }
    public int Weight { get; set; }
    public string Sex { get; set; }

}

我特别想知道您的情况找出问题所在。

I would be particularly interested to know how you go about figuring out what the problem is here.

谢谢

推荐答案

问题在于 DataGrid 中的第一项在首次加载时已经被选中。但是，它并没有真正被选中，也没有被选中并且组也没有展开。但是，当您第一次单击第一个项目时， DataGrid 不能分辨出差异，因为 SelectedIndex 已经是0。这确实很烦人，我早些时候也注意到类似的行为。

The problem is that the first item in the DataGrid is already selected when it's first loaded. However, it isn't really selected, it doesn't appear selected and group isn't expanded. But when you click on the first item for the first time, the DataGrid can't tell the difference since SelectedIndex was already 0. This is really annoying and I noticed similar behavior several times earlier.

作为一种解决方法，您可以取消选择 Loaded中的第一项 DataGrid的事件

As a workaround, you can unselect the first item in the Loaded event of the DataGrid

<DataGrid Loaded="dataGrid1_Loaded"
          ...>

事件处理程序：请注意，SelectedIndex为0

private void dataGrid1_Loaded(object sender, RoutedEventArgs e)
{
    DataGrid dataGrid = sender as DataGrid;
    dataGrid.SelectedItem = null;
}

这篇关于WPF DataGrid问题的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！