Wpf按钮数据触发器

Question

我有一个wpf格式的按钮,按钮在mvvm应用程序中有图像文本,当我点击它将附加文件的按钮,我的要求是当它成功附加我想要从按钮中删除图像并想要更新带有一些文字的按钮.

 <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

如果像您一样Button.Content在<Button>标记本身中设置,则它将优先于任何样式值.

您需要直接将StackPanel移出<Button.Content>标记,并将其放在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>

有关更多信息,请参阅MSDN的依赖项属性优先级列表.