如何使用相对绑定模式= FindAncestor [英] How to use relative binding Mode=FindAncestor

问题描述

我有一个ListView控件，具有3列：名称，姓氏和地址。我想要所有3列具有相同的宽度。我想出的唯一方法是将每列的宽度绑定到祖先的ActualWidth，并使用转换器将此宽度除以3，如下所示：

 < GroupBox> 
< ListView Name =PeopleItemsSource ={Binding peopleList}> 
< ListView.View> 
< GridView> 
< GridViewColumn Header =nameDisplayMemberBinding ={Binding Name}> 
< GridViewColumn.Width> 
< Binding Path =ActualWidthSource ={RelativeSource Mode = FindAncestor，AncestorType = {x：Type GroupBox}}Converter ={StaticResource ListViewConverter}/> 
< /GridViewColumn.Width> 
< GridViewColumn Header =surname...> 
 ... 
< / GridViewColumn> 
< GridViewColumn Header =address...> 
 ... 
< / GridViewColumn> 
< / GridViewColumn> 
< / GridView> 
< /ListView.View> 
< / ListView> 
< / GroupBox> 
  

转换类是：

  class ListViewConverter：IValueConverter 
 {
 public object Convert（object value，Type targetType，object parameter，CultureInfo culture）
 {
 double state =双）值; 
 return state / 3; 
} 
 
 public object ConvertBack（object value，Type targetType，object parameter，CultureInfo culture）
 {
 return null; 
} 
} 
  

但这不行。我认为也许GroupBox不是GridViewColumn.Width的祖先。
也许我错了，有一个简单的方法呢？

解决方案

你是对的， GroupBox不是祖先 - 这是因为GridViewColumn没有添加到可视化树中，因此依赖视觉树导航的绑定将无法正常工作。您可以将列绑定到静态资源：

为了实现您以后的需求，将需要相当多的自定义代码。请参阅MSDN论坛主题：

http://social.msdn.microsoft.com/forums/en-US/wpf/thread/83bd7ab9-3407-461f-a0bc-69e04870075c

这里的代码为指定列大小提供了更多选项：

http://www.codeproject.com/KB/grid/ListView_layout_manager.aspx

I have a ListView control that has 3 columns: Name, Surname and address. I want all 3 columns to have the same width. The only way I came up with was to bind each column's width to the ActualWidth of the ancestor and use a convertor to divide this width by 3 as follows:

<GroupBox>
    <ListView Name="People" ItemsSource="{Binding peopleList}">
        <ListView.View>
                <GridView >
                        <GridViewColumn Header="name" DisplayMemberBinding="{Binding Name}">
                                <GridViewColumn.Width>
                                        <Binding Path="ActualWidth" Source="{RelativeSource Mode=FindAncestor, AncestorType={x:Type GroupBox}}" Converter ="{StaticResource ListViewConverter}"/>
                                    </GridViewColumn.Width>
            <GridViewColumn Header="surname" ...>
                ...
            </GridViewColumn>
            <GridViewColumn Header="address" ...>
                ...
            </GridViewColumn>
                            </GridViewColumn>
                    </GridView>
            </ListView.View>
   </ListView>
</GroupBox>

The convertion class is:

class ListViewConverter: IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
    {
        double state = (double)value;
        return state / 3;
    }

    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
    {
        return null;
    }
}

But this doesn't work. I think that maybe the GroupBox is not an ancestor of GridViewColumn.Width. Maybe I got it all wrong and there is a much simpler way to do this?

解决方案

You are correct, GroupBox is not an ancestor - this is because the GridViewColumn is not added to the visual tree, so bindings that rely on visual tree navigation will not work. You could bind your columns to a static resource instead:

To achieve what you are after will require quite a bit of custom code. See teh following MSDN forum thread:

http://social.msdn.microsoft.com/forums/en-US/wpf/thread/83bd7ab9-3407-461f-a0bc-69e04870075c

And the code here that gives much more options for specifying column sizes:

http://www.codeproject.com/KB/grid/ListView_layout_manager.aspx

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