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我試圖從Extended WPF Toolkit中重新設置DateTimePicker的控制模板。下面是什麼應該看起來像一個畫面：
帶有現有零件的Restyle控制模板
這裏的原代碼的相關部分：
[TemplatePart(Name = PART_Calendar, Type = typeof(Calendar))]
[TemplatePart(Name = PART_TimeUpDown, Type = typeof(TimePicker))]
public class DateTimePicker : DateTimePickerBase
{
private const string PART_Calendar = "PART_Calendar";
private const string PART_TimeUpDown = "PART_TimeUpDown";
public override void OnApplyTemplate()
{
base.OnApplyTemplate();
if(_calendar != null)
_calendar.SelectedDatesChanged -= Calendar_SelectedDatesChanged;
_calendar = GetTemplateChild(PART_Calendar) as Calendar;
if(_calendar != null)
{
_calendar.SelectedDatesChanged += Calendar_SelectedDatesChanged;
_calendar.SelectedDate = Value ?? null;
_calendar.DisplayDate = Value ?? this.ContextNow;
this.SetBlackOutDates();
}
_timePicker = GetTemplateChild(PART_TimeUpDown) as TimePicker;
}
}
<Style TargetType="{x:Type local:DateTimePicker}">
...
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:DateTimePicker}">
...
<StackPanel>
<Calendar x:Name="PART_Calendar" BorderThickness="0" />
<local:TimePicker x:Name="PART_TimeUpDown" ... />
</StackPanel>
...
</ControlTemplate>
</Setter.Value>
<Setter>
</Style>
現在因爲DateTimePicker在後面的代碼中有一些相當不錯的邏輯，用於調整某些事件日曆部分的屬性，我不想重新發明輪子。理想情況下，我想能夠簡單地restyle這樣的控制：
CustomStyles.xaml
<Style x:Key="MetroDateTimePicker" TargetType="{x:Type xctk:DateTimePicker}">
<Setter Property="Foreground" Value="{DynamicResource TextBrush}"/>
<Setter Property="Background" Value="{DynamicResource ControlBackgroundBrush}"/>
<Setter Property="BorderThickness" Value="1"/>
<Setter Property="BorderBrush" Value="{DynamicResource TextBoxBorderBrush}"/>
<Setter Property="FocusVisualStyle" Value="{x:Null}"/>
<Setter Property="FontFamily" Value="{DynamicResource ContentFontFamily}"/>
<Setter Property="FontSize" Value="{DynamicResource ContentFontSize}"/>
<Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst"/>
<Setter Property="Stylus.IsFlicksEnabled" Value="False"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type xctk:DateTimePicker}">
<Grid>
<Border x:Name="Base"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
<Grid Margin="5">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<xctk:ButtonSpinner x:Name="PART_Spinner"
Grid.Column="0"
BorderThickness="0"
IsTabStop="False"
Background="Transparent"
Style="{StaticResource MetroButtonSpinner}"
AllowSpin="{TemplateBinding AllowSpin}"
ShowButtonSpinner="{TemplateBinding ShowButtonSpinner}">
<xctk:WatermarkTextBox x:Name="PART_TextBox"
BorderThickness="0"
Background="Transparent"
FontFamily="{TemplateBinding FontFamily}"
FontSize="{TemplateBinding FontSize}"
FontStretch="{TemplateBinding FontStretch}"
FontStyle="{TemplateBinding FontStyle}"
FontWeight="{TemplateBinding FontWeight}"
Foreground="{TemplateBinding Foreground}"
HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
IsReadOnly="{Binding IsReadOnly, RelativeSource={RelativeSource TemplatedParent}}"
MinWidth="20"
AcceptsReturn="False"
Padding="0"
TextAlignment="{TemplateBinding TextAlignment}"
TextWrapping="NoWrap"
Text="{Binding Text, RelativeSource={RelativeSource TemplatedParent}}"
TabIndex="{TemplateBinding TabIndex}"
Watermark="{TemplateBinding Watermark}"
WatermarkTemplate="{TemplateBinding WatermarkTemplate}" />
</xctk:ButtonSpinner>
<ToggleButton x:Name="_calendarToggleButton"
Background="{TemplateBinding Background}"
Grid.Column="1"
IsChecked="{Binding IsOpen, RelativeSource={RelativeSource TemplatedParent}}"
Style="{DynamicResource ChromelessButtonStyle}"
Foreground="{TemplateBinding Foreground}"
IsTabStop="False">
<Path Fill="{TemplateBinding Foreground}"
Data="..."
Stretch="Uniform">
<Path.Width>
<Binding RelativeSource="{RelativeSource TemplatedParent}"
Path="FontSize"
Converter="{x:Static shared:FontSizeOffsetConverter.Instance}">
<Binding.ConverterParameter>
<sys:Double>4</sys:Double>
</Binding.ConverterParameter>
</Binding>
</Path.Width>
<Path.Height>
<Binding RelativeSource="{RelativeSource TemplatedParent}"
Path="FontSize"
Converter="{x:Static shared:FontSizeOffsetConverter.Instance}">
<Binding.ConverterParameter>
<sys:Double>4</sys:Double>
</Binding.ConverterParameter>
</Binding>
</Path.Height>
</Path>
</ToggleButton>
</Grid>
<Popup x:Name="PART_Popup"
AllowsTransparency="True"
IsOpen="{Binding IsChecked, ElementName=_calendarToggleButton}"
PopupAnimation="{DynamicResource {x:Static SystemParameters.ComboBoxPopupAnimationKey}}"
StaysOpen="False">
<Border Padding="3"
Background="{DynamicResource WhiteBrush}"
BorderBrush="{DynamicResource ComboBoxPopupBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Effect="{DynamicResource DropShadowBrush}">
<StackPanel>
<Calendar x:Name="Part_Calendar"
BorderThickness="0"
MinWidth="115"
DisplayDateStart="{Binding Minimum, RelativeSource={RelativeSource TemplatedParent}}"
DisplayDateEnd="{Binding Maximum, RelativeSource={RelativeSource TemplatedParent}}"
IsTodayHighlighted="False"/>
<xctk:TimePicker x:Name="PART_TimeUpDown"
Style="{StaticResource MetroTimePicker}"
Background="{DynamicResource {x:Static SystemColors.WindowBrushKey}}"
Foreground="{DynamicResource {x:Static SystemColors.WindowTextBrushKey}}"
Format="{TemplateBinding TimeFormat}"
FormatString="{TemplateBinding TimeFormatString}"
Value="{Binding Value, RelativeSource={RelativeSource TemplatedParent}}"
Minimum="{Binding Minimum, RelativeSource={RelativeSource TemplatedParent}}"
Maximum="{Binding Maximum, RelativeSource={RelativeSource TemplatedParent}}"
ClipValueToMinMax="{Binding ClipValueToMinMax, RelativeSource={RelativeSource TemplatedParent}}"
IsUndoEnabled="{Binding IsUndoEnabled, RelativeSource={RelativeSource TemplatedParent}}"
AllowSpin="{TemplateBinding TimePickerAllowSpin}"
ShowButtonSpinner="{TemplateBinding TimePickerShowButtonSpinner}"
Watermark="{TemplateBinding TimeWatermark}"
WatermarkTemplate="{TemplateBinding TimeWatermarkTemplate}"
Visibility="{TemplateBinding TimePickerVisibility}"
Margin="3 0 3 3"/>
</StackPanel>
</Border>
</Popup>
</Grid>
<ControlTemplate.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding="{Binding IsReadOnly, RelativeSource={RelativeSource Self}}" Value="False" />
<Condition Binding="{Binding AllowTextInput, RelativeSource={RelativeSource Self}}" Value="False" />
</MultiDataTrigger.Conditions>
<Setter Property="IsReadOnly" Value="True" TargetName="PART_TextBox" />
</MultiDataTrigger>
<DataTrigger Binding="{Binding IsReadOnly, RelativeSource={RelativeSource Self}}" Value="True">
<Setter Property="IsReadOnly" Value="True" TargetName="PART_TextBox" />
</DataTrigger>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
注：這不是我改變的唯一的事情;實際上有兩種我省略的樣式（MetroTimePicker和MetroButtonSpinner）。一切看起來都很不錯，但它並不正確。每當我在我的代碼中設置一個斷點（在調用ApplyTemplate之後）時，我可以看到私有的_calendar字段爲空。直接調用也會返回null（這可能在Watch或Immediate窗口中）。
看來，當我應用自定義樣式時，它不再能夠拾取模板中指定的元素。我一定會錯過一些東西，因爲我認爲我可以應用幾乎所有的控件模板，只要所有命名的部分在那裏（並且具有合適的類型）。所以我的問題是，如何將自定義模板應用於WPF控件，並確保與其命名組件的任何邏輯繼續按預期工作？
這是一個非常特殊的特別場景。除非你有一些特定的共享異常信息/錯誤，這可能有助於演繹推理的整個排序進行故障排除，否則需要專門研究這件事情？ –
@ChrisW。對不起，我現在一直在圍繞這個問題困擾我的大腦。完整的風格非常大（實際上涉及3種不同的風格），所以我不想在這裏介入太多。然而，我認爲核心問題是'_calendar'字段爲空，我想不出任何會發生的原因，因爲我的樣式的整體結構實際上與原始樣式非常相似。沒有例外。 –
...並且您確定您正在使用所有PART_ * s？看到一切都可能有所幫助，打賭它是覆蓋控制模板的一些細微的細節。 –