网格.行动态调整大小

Question

我在Grid上使用MultiBinding和MultiValueConverter，以便根据所有Grid.Row s的ActualHeight设置每个Grid.Row的MaxHeight。

               <RowDefinition x:Name="grdRow1" Height="Auto" >
                    <RowDefinition.MaxHeight>
                        <MultiBinding Converter="{StaticResource CalculateMaxHeightConverter}" Mode="TwoWay" UpdateSourceTrigger="PropertyChanged">
                            <Binding Path="ActualHeight" ElementName="grdRow1" />
                            <Binding Path="ActualHeight" ElementName="grdRow2" />
                            <Binding Path="ActualHeight" ElementName="grdRow3" />
                            <Binding Path="ActualHeight" ElementName="grdRow4" />
                            <Binding Path="ActualHeight" ElementName="grdRow5" /> 
                        </MultiBinding>
                    </RowDefinition.MaxHeight>
                </RowDefinition>

多转换器：

public class AvailableHeightConverter : IMultiValueConverter
{
    public double PanelHeight { get; set; }
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        if (values == null)
            return Binding.DoNothing;
        double currentHeight = 0d;
        double availableHeight = 0d;
        foreach (object value in values)
        {
            currentHeight += (double)value;
        }
        availableHeight = PanelHeight - currentHeight;
        if (availableHeight < 0)
            return Binding.DoNothing;
        return availableHeight;
    }
    public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new NotImplementedException();
    }
}

UserControl.资源：

<cvc:AvailableHeightConverter x:Key="CalculateMaxHeightConverter" PanelHeight="1080" />

我的问题（一个伪问题）是，每当Grid.Row的ActualHeight发生变化时，我都无法弄清楚如何使用UpdateSourceTrigger。

Answer 1

您的xaml有两个问题（据我所见，没有亲自尝试）

1. ActualHeight没有设置器，因此需要使用Mode="单向"
2. 将grdRow1的MaxHeight绑定到所有行ActualHeight（包括grdRow1本身）可能会产生一个无休止的调整大小循环

尝试以下操作：

            <RowDefinition x:Name="grdRow1" Height="Auto" >
                <RowDefinition.MaxHeight>
                    <MultiBinding Converter="{StaticResource CalculateMaxHeightConverter}" Mode="OneWay" UpdateSourceTrigger="PropertyChanged">
                        <Binding Path="ActualHeight" ElementName="grdRow2" Mode="OneWay" />
                        <Binding Path="ActualHeight" ElementName="grdRow3" Mode="OneWay" />
                        <Binding Path="ActualHeight" ElementName="grdRow4" Mode="OneWay" />
                        <Binding Path="ActualHeight" ElementName="grdRow5" Mode="OneWay" /> 
                    </MultiBinding>
                </RowDefinition.MaxHeight>
            </RowDefinition>

Answer 2

好。在试验了各种各样的senarios之后，我发现Binding行的ActualHeight不会通知MultiBinding更改。@christoph注意到的（2.）也很有帮助。所以我最终绑定了TextBox的ActualWidth，如下所示：

对于第1行

            <RowDefinition x:Name="grdRow1" Height="Auto" >
            <RowDefinition.MaxHeight>
                <MultiBinding Converter="{StaticResource CalculateMaxHeightConverter}">
                    <Binding Path="ActualHeight" ElementName="txtBox2" Mode="OneWay" />
                    <Binding Path="ActualHeight" ElementName="txtBox3" Mode="OneWay" />
                    <Binding Path="ActualHeight" ElementName="txtBox4" Mode="OneWay" />
                    <Binding Path="ActualHeight" ElementName="txtBox5" Mode="OneWay" /> 
                </MultiBinding>
            </RowDefinition.MaxHeight>
        </RowDefinition>

对于第2行

        <RowDefinition x:Name="grdRow2" Height="Auto" >
            <RowDefinition.MaxHeight>
                <MultiBinding Converter="{StaticResource CalculateMaxHeightConverter}">
                    <Binding Path="ActualHeight" ElementName="txtBox1" Mode="OneWay" />
                    <Binding Path="ActualHeight" ElementName="txtBox3" Mode="OneWay" />
                    <Binding Path="ActualHeight" ElementName="txtBox4" Mode="OneWay" />
                    <Binding Path="ActualHeight" ElementName="txtBox5" Mode="OneWay" /> 
                </MultiBinding>
            </RowDefinition.MaxHeight>
        </RowDefinition>

并且从（AvailableHeightConverter的）CCD_ 17减去一行的CCD_。

<cvc:AvailableHeightConverter x:Key="CalculateMaxHeightConverter" PanelHeight="1028" />

（过去是1080（一行的-52 MinHeight）