在WPF中实现向导进度控制

<Window x:Class="WpfApp1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp1"
        xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
        xmlns:ei="http://schemas.microsoft.com/expression/2010/interactions"
        xmlns:mah="clr-namespace:MahApps.Metro.Controls;assembly=MahApps.Metro"
        WindowTransitionsEnabled="False"
        mc:Ignorable="d"
        Title="MainWindow"
        Height="450"
        Width="800"
        WindowStartupLocation="CenterScreen"
        Loaded="Window_Loaded"
        Style="{StaticResource DefaultWindow}">

    <Window.DataContext>
        <local:MainWindowViewModel />
    </Window.DataContext>

    <Window.Resources>
        <local:StringToEnumConverter x:Key="StringToEnumConverter"/>
</Window.Resources>

<mah:MetroWindow.RightWindowCommands>
    <mah:WindowCommands>
        <Button x:Name="cmdMinimize"
                Style="{StaticResource WindowMinimizeButton}" />
        <Button x:Name="cmdMaximize"
                Style="{StaticResource WindowMaximizeButton}" />
        <Button x:Name="cmdExit"
                Style="{StaticResource WindowExitButton}" />
    </mah:WindowCommands>
</mah:MetroWindow.RightWindowCommands>

<Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*" />
        <ColumnDefinition Width="auto" />
    </Grid.ColumnDefinitions>

    <Grid.RowDefinitions>
        <RowDefinition Height="auto" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>

    <Grid Grid.Column="0" Grid.ColumnSpan="2" Grid.Row="1" Panel.ZIndex="1">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>

        <Grid.RowDefinitions>
            <RowDefinition Height="auto" />
            <RowDefinition Height="*" />
            <RowDefinition Height="auto" />
        </Grid.RowDefinitions>

        <StackPanel Grid.Column="0" Grid.Row="0" Orientation="Horizontal">
            <telerik:RadButton x:Name="cmdAdd"
                                   Margin="80,5"
                                   Padding="20,0"
                                   FontFamily="Arial"
                                   FontSize="14"
                                   ToolTipService.ShowOnDisabled="true">
                <TextBlock Text="添加任务" />
            </telerik:RadButton>
            <telerik:RadButton x:Name="cmdDelete"
                                   Margin="5"
                                   Padding="20,0"
                                   FontFamily="Arial"
                                   FontSize="14"
                                   ToolTipService.ShowOnDisabled="true">
                <TextBlock Text="删除任务" />
            </telerik:RadButton>
        </StackPanel>

        <telerik:RadBusyIndicator x:Name="radBusyIndicator"
                                    Grid.Column="0"
                                    Grid.Row="1"
                                    Margin="80,5,80,175"
                                    IsBusy="{Binding IsBusy}"
                                    BusyContent="{Binding BusyContent}"
                                    FontFamily="Arial"
                                    FontSize="14