基于组合框选择的WPF按钮已启用覆盖默认样式 [英] WPF Button IsEnabled Based on ComboBox Selection Overwriting default style

问题描述

我有一个正在查看2个组合框的按钮，以确保它们在启用前具有值.问题是我的操作方式是覆盖主题项目中声明的默认样式.

I have a Button that is looking at 2 comboboxes to make sure they have a value before it is enabled. The problem is the way I am doing it is overwriting the default style declared in my theme project.

<Button x:Name="btnOK" VerticalAlignment="Center" Content="OK" IsDefault="True"  Margin="0" Click="btnOK_Click">
                    <Button.Style>
                      <Style BasedOn="{StaticResource DefaultButton}">
                            <Style.Triggers>
                                <DataTrigger Binding="{Binding ElementName=ddlWageTypes, Path=SelectedItem}" Value="{x:Null}">
                                    <Setter Property="Button.IsEnabled" Value="false"/>
                                </DataTrigger>
                                <DataTrigger Binding="{Binding ElementName=ddlJobTitles, Path=SelectedItem}" Value="{x:Null}">
                                    <Setter Property="Button.IsEnabled" Value="false"/>
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </Button.Style>
                </Button>

我尝试将BasedOn ="{StaticResouce MyDefaultButtonStyleName}"添加到样式标签，但在运行时会炸毁.

I've tried adding BasedOn="{StaticResouce MyDefaultButtonStyleName}" to the style tag but it blows up at runtime.

错误是'System.Windows.Style'值无法分配给对象'System.Windows.Controls.Button'的属性'Style'.只能基于具有基本类型'IFrameworkInputElement'的目标类型的Style '.标记文件中的对象'System.Windows.Style'错误.

The error is "'System.Windows.Style' value cannot be assigned to property 'Style' of object 'System.Windows.Controls.Button'. Can only base on a Style with target type that is base type 'IFrameworkInputElement'. Error at object 'System.Windows.Style' in markup file"

是否可以在XAML中执行此操作而不会覆盖默认样式.

Is there a was to do this in XAML without overwriting default style.

代码示例已更新. 我在OKButtonStyle上收到一条错误消息，提示无法将元素添加到属性'资源'，因为如果该属性使用显式的集合标记，则该属性只能有一个子元素.标记文件中对象'System.Windows.Style'的错误"

Code Sample Updated. I get an error on OKButtonStyle saying "Cannot add element to property 'Resources', because the property can have only one child element if it uses an explicit collection tag. Error at object 'System.Windows.Style' in markup file "

<UserControl x:Class="UK.Budgeting.XBAP.ShiftDiff.NewFTEPremiumPaySummary"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:compModel="clr-namespace:System.ComponentModel;assembly=WindowsBase"
    xmlns:local="clr-namespace:UK.Budgeting.XBAP.ShiftDiff">
    <UserControl.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="CellTemplates.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>

      <Style TargetType="{x:Type Button}" x:Key="OKButtonStyle" BasedOn="{StaticResource DefaultButton}">
        <Style.Triggers>
          <DataTrigger Binding="{Binding ElementName=ddlWageTypes, Path=SelectedItem}" Value="{x:Null}">
            <Setter Property="Button.IsEnabled" Value="false"/>
          </DataTrigger>
          <DataTrigger Binding="{Binding ElementName=ddlJobTitles, Path=SelectedItem}" Value="{x:Null}">
            <Setter Property="Button.IsEnabled" Value="false"/>
          </DataTrigger>
        </Style.Triggers>
      </Style>

    </UserControl.Resources>
    <Grid>
        <Rectangle Style="{StaticResource DialogRectangle}"/>
        <Border Style="{StaticResource DialogBorder}">
            <Grid HorizontalAlignment="Center" VerticalAlignment="Center" Background="White">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition/>
                    <ColumnDefinition Width="5"/>
                    <ColumnDefinition MinWidth="300"/>
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition/>
                    <RowDefinition Height="2"/>
                    <RowDefinition/>
                    <RowDefinition Height="2"/>
                    <RowDefinition/>
                    <RowDefinition Height="2"/>
                    <RowDefinition/>
                </Grid.RowDefinitions>

                <TextBlock Grid.Column="0" Grid.Row="0" Style="{StaticResource LabelStyle}">Wage Type</TextBlock>
                <TextBlock Grid.Column="0" Grid.Row="2" Style="{StaticResource LabelStyle}">Job Title</TextBlock>

                <ComboBox x:Name="ddlWageTypes" VerticalAlignment="Top" Grid.Column="2" Grid.Row="0"
                          DisplayMemberPath="DisplayName"
                          SelectedValuePath="WageTypeCode"/>
                <ComboBox x:Name="ddlJobTitles" VerticalAlignment="Top" Grid.Column="2" Grid.Row="2"
                          DisplayMemberPath="JobTitle"
                          SelectedValuePath="JobCode"/>

                <StackPanel Grid.Column="2" Grid.Row="6" VerticalAlignment="Top" Orientation="Horizontal" Margin="5">
                  <Button x:Name="btnOK" VerticalAlignment="Center" Content="OK" IsDefault="True"  Margin="0" Click="btnOK_Click" Style="{StaticResource OKButtonStyle}"/>
                    <Button x:Name="btnCancel" VerticalAlignment="Center" Content="Cancel" IsCancel="True" Margin="10,0,0,0" Click="btnCancel_Click"/>
                </StackPanel>
            </Grid>
        </Border>
    </Grid>
</UserControl>

推荐答案

这是怎么

BasedOn="{StaticResouce DefaultButton}"

应该引用默认的按钮样式吗?由于DefaultButton是您应用中的未定义资源，因此崩溃.

supposed to refer to the default button style? This crashes because DefaultButton is an undefined resource in your app.

应该是:

BasedOn="{StaticResource {x:Type Button}}"

对不起，回答太仓促.

我现在注意到您的按钮已设置了Style = {}，并指向一种名为OkBUttonStyle的样式.这是应该定义所有内容并基于默认按钮样式的样式.无论如何，我都包括那些触发器.在XAML中，您所说的是样式是按钮的内容.

I noticed now your button has a Style={} set, and is pointing to a style called OkBUttonStyle. This is the style that should define everything and be based on the default button style. By everything, I include those triggers. What you are saying in the XAML is that Style is the Content of your Button.

也许一些代码会有所帮助:

Maybe some code will help:

 <Window x:Class="WindowsApplication7.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="WindowsApplication7" Height="300" Width="300"
    >
  <Window.Resources>
    <Style TargetType="{x:Type Button}" x:Key="defaultButtonStyle">
      <Setter Property="Background" Value="Red" />
    </Style>

    <Style TargetType="{x:Type Button}" x:Key="okButtonStyle" BasedOn="{StaticResource defaultButtonStyle}">
      <Setter Property="Foreground" Value="Green" />
      <Style.Triggers>
        <Trigger Property="IsEnabled" Value="True">
          <Setter Property="Background" Value="Yellow" />
        </Trigger>
        <Trigger Property="IsEnabled" Value="False">
          <Setter Property="Foreground" Value="Blue" />
        </Trigger>
      </Style.Triggers>
    </Style>
  </Window.Resources>
  <StackPanel>
    <Button>System default</Button>
    <Button Style="{StaticResource defaultButtonStyle}">My Default</Button>
    <Button Style="{StaticResource okButtonStyle}">Ok</Button>
    <Button Style="{StaticResource okButtonStyle}" IsEnabled="False">Ok disabled</Button>
  </StackPanel>
</Window>

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