Question

I wanted to two host user control and combine into one user control in WPF.

Answer 1

How do you want your controls laid out? Do you want them placed vertically, like so:

<UserControl Name="MyHostControl">
    <Grid>
        <Grid.ColumnDefintions>
            <ColumnDefinition/>
            <ColumnDefinition/>
        </Grid.ColumnDefintions>

        <local:MyControl1 Grid.Column="0"/>
        <local:MyControl2 Grid.Column="1"/>
    </Grid>
</UserControl>

Are you looking for something else? You’re using WPF, where the flexibility is better than that of any gymnast. You can make your user controls the content of just about any other WPF control you want.