複数凡例の追加

<Grid>
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto" />
        <RowDefinition Height="Auto" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="*" />
        <ColumnDefinition Width="Auto" />
    </Grid.ColumnDefinitions>

    <ig:XamDataChart Grid.ColumnSpan="2" Grid.RowSpan="3">
        ...
        <ig:XamDataChart.Series>
            <ig:LineSeries Title="Volume Series"
                           Legend="{x:Reference Legend1}">
            </ig:LineSeries>
            <ig:FinancialPriceSeries Title="Price Series"
                                     Legend="{x:Reference Legend2}">
            </ig:FinancialPriceSeries>
        </ig:XamDataChart.Series>
    </ig:XamDataChart>
    <ig:Legend x:Name="Legend1"
               Margin="10"
               Grid.Row="0" Grid.Column="1">
    </ig:Legend>
    <ig:Legend x:Name="Legend2"
               Margin="10"
               Grid.Row="1" Grid.Column="1">
    </ig:Legend>
</Grid>