wpf数据触发命令

Question

在下面的代码中按下按钮AddAttachmentCommand正常工作，然后按钮文本更改为Approve，我的要求是我要单击该批准按钮并想要找到新命令isapprovetemplatecommand ...

  <Button ToolTip="Attach file" 
                        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"/>
                                    <Setter Property="Command" Value="{Binding isapprovetemplatecommand}"/>
                                </DataTrigger>
                                <DataTrigger Binding="{Binding IsAttachmentAvailable}" Value="False">
                                    <Setter Property="Visibility" Value="Visible"/>
                                </DataTrigger>
                                <DataTrigger Binding="{Binding IsAttachmentAvailable}" Value="False">
                            </Style.Triggers>
                        </Style>
                    </Button.Style>
                </Button>