Question

我对WPF没有经验，所以请原谅我缺乏理解。

编辑：我正在制作一个简单的国际象棋GUI，这些棋子移动得很好，直到一个人试图移动一个已被移动的棋子。如果我们尝试将棋子移动到之前占用的方格，则点击事件根本不会被激活。如果我们尝试将其移动到之前未触及的方块，则会触发该事件，但UI不会更新。

这里是棋盘的XAML（从这里借来：WPF controls needed to build chess application）：

select gs.ts,
       (select count(*)
        from data_store ds
        where ds.starttime >= g.ts and ds.starttime < g.ts + interval '4 second'
       ) as cnt
from (select generate_series(min(starttime), max(strttime), interval '4 second') as ts
      from data_store
     ) g;

我已经省略了所有作品的多数据触发器，因为它们都很相似。

这是视图模型。我正在使用MVVMLight库：

<Window x:Class="Client.MainWindow"
        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"
        xmlns:local="clr-namespace:Client"
        xmlns:defaults="clr-namespace:butnotquite.Defaults;assembly=butnotquite"
        mc:Ignorable="d" 
        Title="butnotquite Chess" Height="600" Width="600">

    <Window.Resources>
        <DrawingBrush x:Key="Checkerboard" Stretch="None" TileMode="Tile" Viewport="0,0,2,2" ViewportUnits="Absolute">
            <DrawingBrush.Drawing>
                <DrawingGroup>
                    <GeometryDrawing Brush="Tan">
                        <GeometryDrawing.Geometry>
                            <RectangleGeometry Rect="0,0,2,2" />
                        </GeometryDrawing.Geometry>
                    </GeometryDrawing>
                    <GeometryDrawing Brush="Brown">
                        <GeometryDrawing.Geometry>
                            <GeometryGroup>
                                <RectangleGeometry Rect="0,0,1,1" />
                                <RectangleGeometry Rect="1,1,1,1" />
                            </GeometryGroup>
                        </GeometryDrawing.Geometry>
                    </GeometryDrawing>
                </DrawingGroup>
            </DrawingBrush.Drawing>
        </DrawingBrush>

        <Style x:Key="PieceStyle" TargetType="{x:Type Image}">
            <Style.Triggers>
                <MultiDataTrigger>
                <MultiDataTrigger.Conditions>
                    <Condition Binding="{Binding PieceType}" Value="{x:Static defaults:PieceType.None}"/>
                    <Condition Binding="{Binding Color}" Value="{x:Static defaults:Color.None}"/>
                </MultiDataTrigger.Conditions>
                <MultiDataTrigger.Setters>
                    <Setter Property="Image.Source" Value="/Images/empty_square.png" />
                </MultiDataTrigger.Setters>
            </MultiDataTrigger>
            <MultiDataTrigger>
                <MultiDataTrigger.Conditions>
                    <Condition Binding="{Binding PieceType}" Value="{x:Static defaults:PieceType.Pawn}"/>
                    <Condition Binding="{Binding Color}" Value="{x:Static defaults:Color.White}"/>
                </MultiDataTrigger.Conditions>
                <MultiDataTrigger.Setters>
                    <Setter Property="Image.Source" Value="/Images/white_pawn.png" />
                </MultiDataTrigger.Setters>
            </MultiDataTrigger>             
            </Style.Triggers>
        </Style>
    </Window.Resources>

    <Viewbox>
        <ItemsControl Name="ChessboardUI">
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <Canvas Width="8" Height="8" Background="{StaticResource Checkerboard}"/>
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
            <ItemsControl.ItemTemplate>
                <DataTemplate>
                    <Border Name="square"  PreviewMouseDown="square_MouseLeftButtonDown" Width="1" Height="1" >
                        <Image Width="0.8" Height="0.8" Style="{StaticResource PieceStyle}"/>
                    </Border>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
            <ItemsControl.ItemContainerStyle>
                <Style>
                    <Setter Property="Canvas.Left" Value="{Binding Position.X}" />
                    <Setter Property="Canvas.Top" Value="{Binding Position.Y}" />
                </Style>
            </ItemsControl.ItemContainerStyle>
        </ItemsControl>
    </Viewbox>
</Window>

以下是我填写ObservableCollection的方法：

public class PieceViewModel : ViewModelBase
{
    private PieceType pieceType;
    private Color color;
    private Point position;

    public PieceType PieceType
    {
        get
        {
            return this.pieceType;
        }

        set
        {
            this.pieceType = value;
            base.RaisePropertyChanged(() => this.PieceType);
        }
    }

    public Color Color
    {
        get
        {
            return this.color;
        }

        set
        {
            this.color = value;
            base.RaisePropertyChanged(() => this.Color);
        }
    }

    public Point Position
    {
        get
        {
            return this.position;
        }

        set
        {
            this.position = value;
            base.RaisePropertyChanged(() => this.Position);
        }
    }
}

可在此处找到更多代码：https://github.com/YouJinTou/butnotquite/tree/master/Client

感谢您的帮助。

Answer 1

正如lokusking所评论的那样，集合只需要实例化一次，这就是这里的情况;然而，我没有清除它并在每次点击后重新绑定它。这似乎是一个hackish解决方案，但它的确有效。

更改ObservableCollection后单击“事件未触发”

1 个答案: