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为什么多绑定TranslateTransform.X在WPF中似乎不起作用?

[英]Why does MultiBinding a TranslateTransform.X seem not to work in WPF?

I hope I am not being silly asking this, but I am trying to design a graph viewer in WPF being a total newb in the framework; 我希望我不要愚蠢地问这个问题,但是我试图在WPF中设计一个图表查看器,使它成为框架中的一个新手。 although I did come up with a couple of solutions to my problems, the one I'm most proud of... does not work where it should. 尽管我确实为我的问题提出了一些解决方案,但我最引以为傲的解决方案无法在应有的位置起作用。 What I'm trying to do is to place a node on the ItemsControl at a position I calculated with Dijkstra's alg + some maths. 我想做的是在ItemsControl上的一个节点上放置一个我用Dijkstra的算法+一些数学计算出的位置 The problem is that what I move around when using a normal X and Y Binding is the upper-left corner of the TextBlock with Border but what I'd like to manpulate is their center instead. 问题是,当我使用普通的X和Y绑定时,我到处走动的是带有边框的TextBlock的左上角,但是我想操纵的是它们的中心 Thus, my nodes end up sticking down and to the right from the point I specify, not centered on it. 因此,我的节点最终从我指定的点开始向下并向右伸出,而不是居中。

I finally settled for a Multibinding using the X/Y property of my NodeViewModel and the Grid's ActualWidth/Height. 我终于使用NodeViewModel的X / Y属性和网格的ActualWidth / Height解决了Multibinding问题。 What happens is that all my nodes get placed at (0,0) ! 发生的事情是我所有的节点都放在(0,0) I even debugged the code and looked at the converter, but the return value seems OK. 我什至调试了代码并查看了转换器,但是返回值似乎还可以。 I even tried some random things like binding to other properties etc. 我什至尝试了一些随机的事情,例如绑定到其他属性等。

I am totally puzzled. 我完全不解。

So one question would be - does MultiBinding work that way? 因此,一个问题将是-MultiBinding是否以这种方式工作? Or am I making some stupid mistake? 还是我犯了一些愚蠢的错误? I'll post my Converter below the XAML code. 我将在XAML代码下面发布我的Converter。 The parts in XAML cut out are a tooltip and an embedded ItemsControl, but cutting these out changes nothing (except for improving the clarity of the code). XAML中切出的部分是一个工具提示和一个嵌入式ItemsControl,但是切出这些内容不会改变任何东西(除了提高代码的清晰度之外)。 The casting in the converter is because casting directly to float does not work for me (but that's irrelevat - it works the way it is even if it's not very beautiful). 转换器中的转换是因为直接对float进行转换对我不起作用(但这无关紧要-即使它不是很漂亮,它的工作方式也是如此)。

And another question would be - can I do it in any simpler way? 另一个问题是-我能以任何更简单的方式做到吗? Like manipulate the center of the TextBlock directly? 喜欢直接操纵TextBlock的中心吗?

XAML: XAML:

    <Grid>
        <ItemsControl ItemsSource="{Binding Source={StaticResource Nodes}, Path=Nodes}">
            <ItemsControl.ItemTemplate>
                <DataTemplate DataType="vievModels:NodeViewModel">
                    <Grid>
                        <Grid x:Name="nodeGrid">
                            <Grid.RenderTransform>
                                <TranslateTransform>
                                    <TranslateTransform.X>
                                        <MultiBinding Converter="{StaticResource PositionConverter}">
                                            <Binding Path="Position.X"/>
                                            <Binding ElementName="nodeGrid" Path="ActualWidth"/>
                                        </MultiBinding>
                                    </TranslateTransform.X>
                                    <TranslateTransform.Y>
                                        <MultiBinding Converter="{StaticResource PositionConverter}">
                                            <Binding Path="Position.Y"/>
                                            <Binding ElementName="nodeGrid" Path="ActualHeight"/>
                                        </MultiBinding>
                                    </TranslateTransform.Y>
                                </TranslateTransform>
                            </Grid.RenderTransform>
                            <Border BorderBrush="Black" BorderThickness="2" CornerRadius="7">
                                <Border.Background>
                                    <SolidColorBrush Color="{Binding Color}" Opacity="0.5"/>
                                </Border.Background>
                                <TextBlock x:Name="Label" Margin="5,5,5,5" MaxWidth="160" TextAlignment="Center" TextWrapping="Wrap" FontFamily="Lucida Console" VerticalAlignment="Center" HorizontalAlignment="Center" Text="{Binding Path=Label}"/>
                            </Border>
...
                        </Grid>
...
                    </Grid>
                </DataTemplate>
            </ItemsControl.ItemTemplate>
            <ItemsControl.ItemsPanel>
                <ItemsPanelTemplate>
                    <Canvas Background="Transparent"/>
                </ItemsPanelTemplate>
            </ItemsControl.ItemsPanel>
        </ItemsControl>
    </Grid>

C#: C#:

public class PositionConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        float point = float.Parse(values[0].ToString());
        float size = float.Parse(values[1].ToString());
        return point - size / 2;

    }
    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

Cheers, Michael 干杯,迈克尔

Just as I thought - a silly mistake. 正如我所想-一个愚蠢的错误。 The converted property is of double precision and cannot have float assigned to it. 转换后的属性具有精度,并且不能为其分配浮点数。 I had to learn how to turn on the debug output to see that. 我必须学习如何打开调试输出才能看到。

如果在Grid上设置RenderTransformOrigin =“。5,.5”,则它应与原始值绑定。

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