我有一个WPF页面，其中包含一个Grid。
它有三行。第0行包含一个GridView，Height="*"。第1行包含一个GridSplitter，Height="auto"。第2行包含一个详细表单，Height="2*"。
问题在于-我有一个按钮，应该可以切换详细表单的可见性。这可以正常工作。除了它只隐藏第2行中的表单，它没有扩展第0行的网格来填充空间。我想要的是，按钮切换到GridView填满所有空间，然后切换回原来的状态。
显然，在行内操作表单的可见性无法实现我的目标。
但我需要做些什么调整？
如果有人想要一个纯XAML的解决方案，我能够通过使用样式、Setter和Trigger的方法来隐藏分隔器和相关行。
我使用了静态资源来设置我的样式，当特定的布尔值被设置时，这些样式将更改Height和MaxHeight属性。
<Style x:Key="showRow" TargetType="{x:Type RowDefinition}">
<Style.Setters>
<Setter Property="Height" Value="*"/>
</Style.Setters>
<Style.Triggers>
<DataTrigger Binding="{Binding MyShowRowBool}" Value="False">
<DataTrigger.Setters>
<Setter Property="Height" Value="0"/>
<Setter Property="MaxHeight" Value="0"/>
</DataTrigger.Setters>
</DataTrigger>
</Style.Triggers>
</Style>
我只是将样式应用于相关的行定义中，它就完美地起作用了：
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Style="{StaticResource showRow}"/>
<RowDefinition Style="{StaticResource showRow}"/>
</Grid.RowDefinitions>
<Grid Name="MyGrid">
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition Height="Auto" />
<RowDefinition />
</Grid.RowDefinitions>
<MyControl1 ... Grid.Row="0" />
<GridSplitter Grid.Row="1" VerticalAlignment="Center" HorizontalAlignment="Stretch" ShowsPreview="True" Height="5" />
<MyControl2 ... Grid.Row="2" />
</Grid>
然后我可以使用以下代码隐藏第二个控件（折叠分隔器）（相当于在XAML中设置Height="0"）：
MyGrid.RowDefinitions[2].Height = new GridLength(0);
使用以下代码展开它（与在XAML中设置Height="1*"相当，这是RowDefinition的默认值）：
MyGrid.RowDefinitions[2].Height = new GridLength(1, GridUnitType.Star);
当用户移动分隔条时，它所做的事情是将内容进行分割。
我必须在自己的应用程序中引入一个附加依赖属性来处理这个问题：
<Grid c:GridSplitterController.Watch="{Binding ElementName=GS_DetailsView}">
<Grid.RowDefinitions>
<RowDefinition Height="1*" />
<RowDefinition Height="200" />
</Grid.RowDefinitions>
<SomeControl Grid.Row="0" />
<GridSplitter x:Name="GS_DetailsView"
Height="4"
Grid.Row="1"
VerticalAlignment="Top"
HorizontalAlignment="Stretch"
ResizeBehavior="PreviousAndCurrent"
ResizeDirection="Rows"
Visibility="{Binding ShowDetails,
Converter={StaticResource boolvis}}" />
<OtherControl Grid.Row="1"
Margin="0,4,0,0"
Visibility="{Binding ShowDetails,
Converter={StaticResource boolvis}}" />
</Grid>
首先在DependencyObject上定义一个合适的附加属性：
public static GridSplitter GetWatch(DependencyObject obj)
{
return (GridSplitter)obj.GetValue(WatchProperty);
}
public static void SetWatch(DependencyObject obj, GridSplitter value)
{
obj.SetValue(WatchProperty, value);
}
public static readonly DependencyProperty WatchProperty =
DependencyProperty.RegisterAttached(
"Watch",
typeof(GridSplitter),
typeof(DependencyObject),
new UIPropertyMetadata(null, OnWatchChanged));
接着监听 IsVisibleChanged 事件：
private static void OnWatchChanged(DependencyObject obj,
DependencyPropertyChangedEventArgs e)
{
if (obj == null) return;
if (obj is Grid)
{
var grid = obj as Grid;
var gs = e.NewValue as GridSplitter;
if (gs != null)
{
gs.IsVisibleChanged += (_sender, _e) =>
{
UpdateGrid(
grid,
(GridSplitter)_sender,
(bool)_e.NewValue,
(bool)_e.OldValue);
};
}
}
}
一旦您正在观察这些变化，您需要保存或还原您正在观察的行（为了简洁起见，我仅包括行）中的GridLength值：
// Given: static Dictionary<DependencyObject, GridLength> oldValues;
private static void UpdateGrid(Grid grid, GridSplitter gridSplitter, bool newValue, bool oldValue)
{
if (newValue)
{
// We're visible again
switch (gridSplitter.ResizeDirection)
{
case GridResizeDirection.Columns:
break;
case GridResizeDirection.Rows:
int ridx = (int)gridSplitter.GetValue(Grid.RowProperty);
var prev = grid.RowDefinitions.ElementAt(GetPrevious(gridSplitter, ridx));
var curr = grid.RowDefinitions.ElementAt(GetNext(gridSplitter, ridx));
if (oldValues.ContainsKey(prev) && oldValues.ContainsKey(curr))
{
prev.Height = oldValues[prev];
curr.Height = oldValues[curr];
}
break;
}
}
else
{
// We're being hidden
switch (gridSplitter.ResizeDirection)
{
case GridResizeDirection.Columns:
break;
case GridResizeDirection.Rows:
int ridx = (int)gridSplitter.GetValue(Grid.RowProperty);
var prev = grid.RowDefinitions.ElementAt(GetPrevious(gridSplitter, ridx));
var curr = grid.RowDefinitions.ElementAt(GetNext(gridSplitter, ridx));
switch (gridSplitter.ResizeBehavior)
{
// Naively assumes only one type of collapsing!
case GridResizeBehavior.PreviousAndCurrent:
oldValues[prev] = prev.Height;
prev.Height = new GridLength(1.0, GridUnitType.Star);
oldValues[curr] = curr.Height;
curr.Height = new GridLength(0.0);
break;
}
break;
}
}
}
现在只需要适当实现GetPrevious和GetNext方法：
private static int GetPrevious(GridSplitter gridSplitter, int index)
{
switch (gridSplitter.ResizeBehavior)
{
case GridResizeBehavior.PreviousAndNext:
case GridResizeBehavior.PreviousAndCurrent:
return index - 1;
case GridResizeBehavior.CurrentAndNext:
return index;
case GridResizeBehavior.BasedOnAlignment:
default:
throw new NotSupportedException();
}
}
private static int GetNext(GridSplitter gridSplitter, int index)
{
switch (gridSplitter.ResizeBehavior)
{
case GridResizeBehavior.PreviousAndCurrent:
return index;
case GridResizeBehavior.PreviousAndNext:
case GridResizeBehavior.CurrentAndNext:
return index + 1;
case GridResizeBehavior.BasedOnAlignment:
default:
throw new NotSupportedException();
}
}