【发布时间】：2014-04-09 13:35:18
【问题描述】：
我有一个数据网格，其中CanUserAddRows = "true"。
当我运行程序时，我得到一个空白行。当我在该行中输入数据时，它工作得很好。但是在那之后，如果我尝试添加新行，我将无法添加它，因为按 Enter 或 TAB 没有得到空白行。
这是我的数据网格所在的页面：
<Page x:Class="WPF_Client.Pages.Masters.Multiple.Groups"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:helpers="clr-namespace:WPF_Client.HelperClasses"
xmlns:vm="clr-namespace:WPF_Client.ViewModels.Masters.Multiple"
mc:Ignorable="d"
d:DesignHeight="760" d:DesignWidth="1366"
Title="Groups">
<Page.DataContext>
<vm:GroupsViewModel />
</Page.DataContext>
<Page.Resources>
<CollectionViewSource x:Key="GroupNamesWithCorrespondingEffectsCollection" Source="{Binding GroupNamesWithCorrespondingEffects}" />
</Page.Resources>
<Grid>
<DataGrid CanUserAddRows="True" CanUserReorderColumns="False" CanUserSortColumns="False" CanUserDeleteRows="True"
ItemsSource="{Binding Groups}" AutoGenerateColumns="False">
<DataGrid.Resources>
<CompositeCollection x:Key="Items">
<ComboBoxItem IsEnabled="False" Background="#FF2A2A2A" Foreground="White">
<Grid TextElement.FontWeight="Bold" >
<Grid.ColumnDefinitions>
<ColumnDefinition SharedSizeGroup="A" />
<ColumnDefinition Width="50" />
<ColumnDefinition SharedSizeGroup="B" />
</Grid.ColumnDefinitions>
<Grid.Children>
<TextBlock Grid.Column="0" Text="Group Name" />
<TextBlock Grid.Column="2" Text="Effect" />
</Grid.Children>
</Grid>
</ComboBoxItem>
<CollectionContainer Collection="{Binding Source={StaticResource GroupNamesWithCorrespondingEffectsCollection}}" />
</CompositeCollection>
<DataTemplate DataType="{x:Type helpers:GroupNameWithCorrespondingEffect}">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition SharedSizeGroup="A" />
<ColumnDefinition Width="50" />
<ColumnDefinition SharedSizeGroup="B" />
</Grid.ColumnDefinitions>
<Grid.Children>
<TextBlock Grid.Column="0" Text="{Binding GroupName}" />
<TextBlock Grid.Column="2" Text="{Binding CorrespondingEffect}" />
</Grid.Children>
</Grid>
</DataTemplate>
</DataGrid.Resources>
<DataGrid.Columns>
<DataGridTemplateColumn Header="Name" Width="2*">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBox Text="{Binding GroupName}"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Group" Width="2*">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{DynamicResource Items}"
SelectedValue="{Binding DataContext.SelectedGroupID, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Page}}}"
SelectedValuePath="GroupID" Grid.IsSharedSizeScope="True" TextSearch.TextPath="GroupName">
</ComboBox>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Effect" Width="*" >
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<ComboBox ItemsSource="{Binding DataContext.Effects, RelativeSource={RelativeSource AncestorType={x:Type Page}}}" DisplayMemberPath="Effect"
SelectedValue="{Binding DataContext.SelectedEffectID, RelativeSource={RelativeSource AncestorType={x:Type Page}}}" SelectedValuePath="EffectID"
Visibility="{Binding Path=DataContext.SelectedGroupID,
RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Page}},
Converter={StaticResource effectsVisibilityConverter}}"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Page>
这是我的视图模型：
public class GroupsViewModel : ViewModelBase, IModule
{
public GroupsViewModel()
{
SessionViewModel.Instance.ModulesOpen.Add((IModule)this);
Groups = new ObservableCollection<Group>();
using (Entities db = new Entities())
{
List<GroupNameWithCorrespondingEffect> _GroupNamesWithCorrespondingEffects = (
from g in db.Groups
select new GroupNameWithCorrespondingEffect
{
GroupID = g.GroupID,
GroupName = g.GroupName,
CorrespondingEffect = g.Master_Effects.Effect
}
).ToList();
GroupNamesWithCorrespondingEffects
= new ObservableCollection<GroupNameWithCorrespondingEffect>(
_GroupNamesWithCorrespondingEffects.Where
(
u => !StaticMethods.GetAllChildren(25)
.Select(x => x.GroupID)
.Contains(u.GroupID)
).ToList()
);
Effects = new ObservableCollection<Master_Effects>(from m in db.Master_Effects
select m);
}
}
~GroupsViewModel()
{
SessionViewModel.Instance.ModulesOpen.Remove((IModule)this);
}
private ObservableCollection<Group> _groups;
public ObservableCollection<Group> Groups
{
get
{
return _groups;
}
set
{
_groups = value;
OnPropertyChanged("Groups");
}
}
private ObservableCollection<GroupNameWithCorrespondingEffect> _groupNamesWithCorrespondingEffects;
public ObservableCollection<GroupNameWithCorrespondingEffect> GroupNamesWithCorrespondingEffects
{
get
{
return _groupNamesWithCorrespondingEffects;
}
set
{
_groupNamesWithCorrespondingEffects = value;
OnPropertyChanged("GroupNamesWithCorrespondingEffects");
}
}
private int _selectedGroupID;
public int SelectedGroupID
{
get
{
return _selectedGroupID;
}
set
{
_selectedGroupID = value;
OnPropertyChanged("SelectedGroupID");
}
}
private ObservableCollection<Master_Effects> _effects;
public ObservableCollection<Master_Effects> Effects
{
get
{
return _effects;
}
set
{
_effects = value;
OnPropertyChanged("Effects");
}
}
private int _selectedEffectID;
public int SelectedEffectID
{
get
{
return _selectedEffectID;
}
set
{
_selectedEffectID = value;
OnPropertyChanged("SelectedEffectID");
}
}
public string ModuleFriendlyName
{
get { return "GroupsViewModel"; }
}
public string ModuleName
{
get { return "Groups"; }
}
}
我做错了吗？还是dataGrid的默认行为？
更新：
我已根据您的建议更新了我的代码。这是我的 xaml：
<DataGrid ..............>
<i:Interaction.Triggers>
<i:EventTrigger EventName="PreviewKeyDown">
<i:InvokeCommandAction Command="{Binding DataContext.NewRowCommand, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Page}}}" />
</i:EventTrigger>
</i:Interaction.Triggers>
</DataGrid>
这是我的视图模型：
//在构造函数中： NewRowCommand = new RelayCommand(NewRow);
//在正文中：
public ICommand NewRowCommand { get; set; }
private void NewRow(object obj)
{
MessageBox.Show("PreviewKeyDown on Datagrid invoked.");
}
当我在 DataGrid 的输入区域按任意键时，我成功地在输出中获得 MessageBox。
更新后的问题：
现在，在尝试了你的建议之后，我也遇到了一些问题。
我只想在按 Enter 时显示该消息框（如果它是网格上的默认行为。我不知道默认行为，因为我对 DataGrid 非常陌生。）键在数据网格上。所以，我的实际问题是识别按下的键。
【问题讨论】：