Wpf 按钮数据触发

Question

我的 wpf 表单中有一个按钮，当我单击该按钮时，该按钮在 mvvm 应用程序中具有图像文本，它将附加文件，我的要求是当它成功附加时，我想从按钮中删除图像并想用一些文本更新按钮。

 <StackPanel Grid.Row="3" Orientation="Horizontal" HorizontalAlignment="Right">
            <Button ToolTip="Attach Approval" 
                    Height="25" 
                    Command="{Binding AddAttachmentCommand}" 
                    Margin="5,10,5,10">
                <StackPanel Orientation="Horizontal">
                    <Image Source="/UILibrary;component/Themes/Default/Images/Attach.PNG"/>
                </StackPanel>
                <Button.Style>
                    <Style TargetType="{x:Type Button}">
                        <Style.Triggers>
                            <DataTrigger Binding="{Binding IsAttachmentAvailable}" Value="True">
                                <Setter Property="Visibility" Value="Visible"/>
                                <Setter Property="Content" Value="Appprove"/>
                            </DataTrigger>
                            <DataTrigger Binding="{Binding IsAttachmentAvailable}" Value="False">
                                <Setter Property="Visibility" Value="Visible"/>
                            </DataTrigger>
                        </Style.Triggers>
                    </Style>
                </Button.Style>

            </Button>
            <StackPanel Orientation="Horizontal" 
                        Height="25"  
                        Margin="5,10,5,10"
                        Visibility="{Binding IsAttachmentAvailable, Converter={StaticResource BooleanToVisibilityConverter}}">              
                <TextBlock Margin="3">
                    <Hyperlink Command="{Binding OpenAttachmentCommand}"> 
                        <TextBlock Text="{Binding Attachment.FileName}"/>
                    </Hyperlink>
                </TextBlock>
                <customControls:CloseButton Width="15" Height="15" Command="{Binding RemoveAttachmentCommand}">
                    <customControls:CloseButton>
                        Remove attachment
                    </customControls:CloseButton>
                </customControls:CloseButton>
            </StackPanel>
            <Button Height="25" 
                    Width="80" 
                    Margin="5,10,5,10"
                    Content="Approve" 
                    Command="{Binding ApproveTemplateCommand}"/>
            <Button Height="25" 
                    Width="80" 
                    Margin="5,10,5,10"
                    Content="Preview" 
                Command="{Binding PreviewTemplateCommand}"/>
            <Button Content="Save" 
                Command="{Binding SaveTemplateCommand}" 
                Height="25"
                    Width="80"                    
                    Margin="5,10,5,10"/>
            <Button Height="25"
                    Width="80"
                    Margin="5,10,10,10"
                    Content="Cancel"
                    Command="{Binding CancelCommand}"/>
        </StackPanel>    

Answer 1

如果Button.Content 像您一样在<Button> 标记中设置，它将优先于任何样式值。

您需要将您的 StackPanel 直接移出 <Button.Content> 标记，并将其放入样式或其他数据触发器中。

<Button ToolTip="Attach Approval" 
        Height="25" 
        Command="{Binding AddAttachmentCommand}" 
        Margin="5,10,5,10">
    <Button.Style>
        <Style TargetType="{x:Type Button}">
            <!-- Default Content value -->
            <Setter Property="Content">
                <Setter.Value>
                    <StackPanel Orientation="Horizontal">
                        <Image Source="/UILibrary;component/Themes/Default/Images/Attach.PNG"/>
                    </StackPanel>
                </Setter.Value>
            </Setter>

            <!-- Triggered values -->
            <Style.Triggers>
                <DataTrigger Binding="{Binding IsAttachmentAvailable}" Value="True">
                    <Setter Property="Visibility" Value="Visible"/>
                    <Setter Property="Content" Value="Appprove"/>
                </DataTrigger>
                <DataTrigger Binding="{Binding IsAttachmentAvailable}" Value="False">
                    <Setter Property="Visibility" Value="Visible"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Button.Style>

更多信息请参见MSDN's Dependency Property Precedence List。