<UserControl x:Class="ClassLibrary1.UserControl1"
         xmlns:local="clr-namespace:ClassLibrary1"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
 <UserControl.Template>
    <ControlTemplate>
        <StackPanel>
            <Button Content="Custom Control Text Area 1" IsEnabled="{Binding IsEnabled}"  />
            <ContentPresenter Content="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Content}"/>
            <TextBlock Text="Custom Control Text Area 2" />
        </StackPanel>
    </ControlTemplate>
</UserControl.Template>

namespace ClassLibrary1
{
   public partial class UserControl1 : UserControl
   {
       public UserControl1()
       {
          InitializeComponent();
       }
   }
}

<StackPanel>
    <l:UserControl1>
        <StackPanel >
            <Button Click="Button_Click" Content="Click"/>
            <Button Content="My Control's Content" IsEnabled="{Binding Isbuttonenable}"/>
        </StackPanel>
    </l:UserControl1>

</StackPanel>

namespace ClassLibrary1
{
   public partial class UserControl1 : UserControl
   {
       UserControl1ViewModel model = new UserControl1ViewModel();
       public UserControl1()
       {
          InitializeComponent();
         this.DataContext = model;
       }
    }
}

<StackPanel>
    <l:UserControl1 DataContext="{StaticResource MyUserControl1ViewModelInstance}">
        <StackPanel >
            <Button Click="Button_Click" Content="Click"/>
            <Button Content="My Control's Content" IsEnabled="{Binding Isbuttonenable}"/>
        </StackPanel>
    </l:UserControl1>

</StackPanel>