GridSplitter MinWidth,大小固定

Question

我有一个2列的网格,由GridSplitter使用以下XAML代码分隔:

<Grid>
    <Grid.ColumnDefinitions>
    <ColumnDefinition Width="100" MinWidth="20" />
    <ColumnDefinition Width="10" />
    <ColumnDefinition Width="*" MinWidth="100" />
    </Grid.ColumnDefinitions>

    <Rectangle Fill="Blue" />
    <GridSplitter Grid.Column="1" Background="LightGray" HorizontalAlignment="Stretch" />
    <Rectangle Fill="Yellow" Grid.Column="2" />
</Grid>

问题:忽略右侧列的MinWidth

• 当页面加载时,我肯定需要将第一列宽度设置为"100px",因此它不能是*大小.
• 我不想在第一列上设置MaxWidth

*我知道之前已经解决了,但它始终建议将列大小设置为*或在第一列设置maxWidth ...我不希望这样.

---

找到了解决方案,但它的UGLY!:p,任何人都有更清洁的方式来实现我想要的...... CODELESS(如果可能的话)？

private void Grid_SizeChanged(object sender, SizeChangedEventArgs e)
{
   var g = (Grid)sender;

   Double maxW = e.NewSize.Width - g.ColumnDefinitions[2].MinWidth - g.ColumnDefinitions[1].ActualWidth;
   g.ColumnDefinitions[0].MaxWidth = maxW;
}

Answer 1

最根本的问题是,电网分离器的工作原理是调整左侧列的宽度只并呈右列将出演尺寸以适应剩余空间.

这意味着您要解决的问题实际上是"如何限制左列的最大宽度,以便右列不会太小？".这基本上就是您的代码示例所做的事情.

如果您想要一个可以在XAML中实现的更便携的解决方案,请创建可应用于网格的Silverlight 行为(如下所示).它将附加到父网格的SizeChanged事件,并且几乎完全与您的代码片段相关,但是您可以将它们拖放到Blend中或将它们附加到XAML中.

下面是一个示例行为,我为您举例(基于您自己的代码):

MinWidthSplitterBehavior.cs

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Interactivity;

namespace GridSplitterMinWidth
{
    public class MinWidthSplitterBehavior : Behavior<Grid>
    {
        public Grid ParentGrid { get; set; }

        protected override void OnAttached()
        {
            base.OnAttached();
            ParentGrid = this.AssociatedObject as Grid;
            ParentGrid.SizeChanged += parent_SizeChanged;
        }

        void parent_SizeChanged(object sender, SizeChangedEventArgs e)
        {
            if (ParentGrid.ColumnDefinitions.Count == 3)
            {
                Double maxW = e.NewSize.Width - ParentGrid.ColumnDefinitions[2].MinWidth -
                              ParentGrid.ColumnDefinitions[1].ActualWidth;
                ParentGrid.ColumnDefinitions[0].MaxWidth = maxW;
            }
        }

        protected override void OnDetaching()
        {
            base.OnDetaching();
            if (ParentGrid != null)
            {
                ParentGrid.SizeChanged -= parent_SizeChanged;
            }
        }
    }
}

并像这样使用它:

<UserControl x:Class="GridSplitterMinWidthApp.MainPage"
    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:GridSplitterMinWidth="clr-namespace:GridSplitterMinWidth"
    xmlns:interactivity="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
    xmlns:Controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"
    mc:Ignorable="d"
    d:DesignHeight="300" d:DesignWidth="400">

    <Grid x:Name="LayoutRoot" Background="White">
        <Grid>
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="100" MinWidth="20" />
                <ColumnDefinition Width="10" />
                <ColumnDefinition Width="*" MinWidth="100" />
            </Grid.ColumnDefinitions>
            <interactivity:Interaction.Behaviors>
                <GridSplitterMinWidth:MinWidthSplitterBehavior/>
            </interactivity:Interaction.Behaviors>
            <Rectangle Fill="Blue" />
            <Controls:GridSplitter Grid.Column="1" Background="LightGray" HorizontalAlignment="Stretch">
            </Controls:GridSplitter>
            <Rectangle Fill="Yellow" Grid.Column="2" />
        </Grid>
    </Grid>
</UserControl>