触发的数据触发器没有改变自定义控件的属性(ControlTemplate)
本文关键字：属性 自定义控件 ControlTemplate 改变 数据 触发器 | 更新日期: 2023-09-27 18:13:45
我想改变一个DependcyProperty(Named is as MessageTemplateProperty)，这是在CustomControl和类型是Controltemplate。
但是我不能设置它的值使用datatrigger
但是另一个DependcyProperty(命名为IsShowMessageProperty)是在CustomControl和类型是bool可以使用datatrigger设置。
谁能解释它，为什么，以及如何解决它
自定义代码如下:
public class MessageOverLay : ContentControl
{
static MessageOverLay()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(MessageOverLay),
new FrameworkPropertyMetadata(typeof(MessageOverLay)));
}
#region DependcyProperties
// Template attached property
public static readonly DependencyProperty MessageTemplateProperty =
DependencyProperty.Register("MessageTemplate", typeof(ControlTemplate), typeof(MessageOverLay),
new FrameworkPropertyMetadata(MessageTemplateChanged));
public ControlTemplate MessageTemplate
{
set{SetValue(MessageTemplateProperty, value);}
get{return (ControlTemplate)GetValue(MessageTemplateProperty);}
}
// IsVisible attached property
public static readonly DependencyProperty IsShowMessageProperty =
DependencyProperty.Register("IsShowMessage", typeof(bool), typeof(MessageOverLay),
new PropertyMetadata(IsShowMessageChanged));
public bool IsShowMessage
{
get{return (bool)GetValue(IsShowMessageProperty);}
set{SetValue(IsShowMessageProperty, value);}
}
#endregion DependcyProperties
}
自定义默认主题Generic.xaml
<Style TargetType="{x:Type controls:MessageOverLay}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="controls:MessageOverLay">
<AdornerDecorator>
<Grid>
<ContentPresenter x:Name="PART_Conent"
VerticalAlignment="Stretch"
HorizontalAlignment="Stretch"
Content="{TemplateBinding Content}" />
<Control x:Name="Part_MessageControl" Template="{TemplateBinding MessageTemplate}"
Visibility="{TemplateBinding IsShowMessage,Converter={StaticResource BooleanToVisibilityConverter}}" />
</Grid>
</AdornerDecorator>
</ControlTemplate>
</Setter.Value>
</Setter>
<Setter Property="MessageTemplate">
<Setter.Value>
<ControlTemplate>
<Grid HorizontalAlignment="Left" VerticalAlignment="Bottom">
<Grid Width="150" Height="100" Margin="5 0 0 10">
<Rectangle Stroke="Black" Fill="Yellow" RadiusX="6" RadiusY="6" Margin="0 20 0 0" />
<TextBlock Text="What are you doing?" Margin="5 25 0 0" />
<Button Content="Cancel" Margin="5" VerticalAlignment="Bottom" HorizontalAlignment="Right" />
<Button Content="OK" Margin="5" VerticalAlignment="Bottom" HorizontalAlignment="Left" />
</Grid>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
我想这样使用:
演示XAML: <Window ...>
<Window.Resources>
<ControlTemplate x:Key="GenderPopupTemplate">
<Grid HorizontalAlignment="Left" VerticalAlignment="Bottom">
<Grid Width="200" Height="100" Margin=" 5 0 0 10">
<TextBlock Text="Please Select Gender " Margin="5 25 0 0" />
<Button Content="Male" Margin="5" VerticalAlignment="Bottom" HorizontalAlignment="Left"
Command="{Binding SelectedGenderCommand}" />
<Button Content="FeMale" Margin="5" VerticalAlignment="Bottom" HorizontalAlignment="Right"
Command="{Binding SelectedGenderCommand}" />
</Grid>
</Grid>
</ControlTemplate>
<ControlTemplate x:Key="FacePopupTemplate">
<Grid HorizontalAlignment="Left" VerticalAlignment="Bottom">
<Grid Width="200" Height="100" Margin="5 10 0 0">
<TextBlock Text="Do you like your Face,Now?" Margin="5 25 0 0" />
<Button Content="OK" Margin="5" VerticalAlignment="Bottom" HorizontalAlignment="Left"
Command="{Binding OKCommand}" />
</Grid>
</Grid>
</ControlTemplate>
</Window.Resources>
<controls:MessageOverLay HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
MessageTemplate="{StaticResource GenderPopupTemplate}"
IsShowMessage="True">
<controls:MessageOverLay.Style>
<Style TargetType="{x:Type controls:MessageOverLay}">
<Style.Triggers>
<DataTrigger Binding="{Binding MessageBoxType}" Value="{x:Static viewModels:MessageBoxTypes.SelectView}">
<Setter Property="MessageTemplate" Value="{StaticResource GenderPopupTemplate}"></Setter>
<Setter Property="Height" Value="350"/>
</DataTrigger>
<DataTrigger Binding="{Binding MessageBoxType}" Value="{x:Static viewModels:MessageBoxTypes.MessageView}">
<Setter Property="MessageTemplate" Value="{StaticResource FacePopupTemplate}"></Setter>
<Setter Property="Height" Value="150"/>
</DataTrigger>
</Style.Triggers>
</Style>
</controls:MessageOverLay.Style>
<Grid Background="SeaGreen"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch">
<TextBlock Text="Content"/>
</Grid>
</controls:MessageOverLay>
当MainWindowViewModel的属性MessageBoxType改变时，我想改变MessageTemplate。但我无法存档。
其他相关代码
演示c#代码:
public class MainWindowViewModel : BindableBase
{
public ICommand SelectedGenderCommand { get; }
public ICommand OKCommand { get; }
private MessageBoxTypes _messageBoxType;
public MessageBoxTypes MessageBoxType
{
get { return _messageBoxType; }
set { SetProperty(ref _messageBoxType, value); }
}
private string _title = "Prism Unity Application";
public string Title
{
get { return _title; }
set { SetProperty(ref _title, value); }
}
public MainWindowViewModel()
{
MessageBoxType = MessageBoxTypes.SelectView;
SelectedGenderCommand = new DelegateCommand<object>(SelectedGender);
OKCommand = new DelegateCommand<object>(OK);
}
private void OK(object obj)
{
MessageBoxType = MessageBoxTypes.SelectView;
}
private void SelectedGender(object obj)
{
MessageBoxType = MessageBoxTypes.MessageView;
}
}
public enum MessageBoxTypes
{
SelectView,
MessageView,
ConfirmView
}
这里是完整的演示代码在github，请检查它
当Style Setter要设置依赖属性时，必须不像在
中那样直接赋值所谓的局部值。<controls:MessageOverLay MessageTemplate="{StaticResource GenderPopupTemplate}" ...>
直接赋值的局部值总是比来自Style Setter(和其他可能的来源)的任何值具有更高的优先级，因此Setter没有作用。更多细节可以在这里找到:依赖属性值优先级。
用另一个Style Setter代替直接赋值:
<controls:MessageOverLay ...>
<controls:MessageOverLay.Style>
<Style TargetType="{x:Type controls:MessageOverLay}">
<Setter Property="MessageTemplate"
Value="{StaticResource GenderPopupTemplate}"/>
<Style.Triggers>
...
</Style.Triggers>
</Style>
</controls:MessageOverLay.Style>
...
</controls:MessageOverLay>