Example of two datacontext

First model:

public class FirstModel
{
	public string HelloWorld { get; set; }
	public FirstModel()
	{
		HelloWorld = "First model";
	}
}

Second model:

public class SecondModel
{
	public string HelloWorld { get; set; }

	public SecondModel()
	{
		HelloWorld = "Second model";
	}
}

XAML:

<Window x:Class="TwoDataContext.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:system="clr-namespace:System;assembly=mscorlib"
        xmlns:twoDataContext="clr-namespace:TwoDataContext"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <Grid.Resources>
            <twoDataContext:FirstModel x:Key="FirstModel" />
            <twoDataContext:SecondModel x:Key="SecondModel" />
        </Grid.Resources>
        <TextBox DataContext = "{StaticResource FirstModel}" HorizontalAlignment="Left" Height="23" Margin="178,64,0,0" TextWrapping="Wrap" Text="{Binding HelloWorld}" VerticalAlignment="Top" Width="120"/>
        <TextBox DataContext = "{StaticResource SecondModel}" HorizontalAlignment="Left" Height="23" Margin="178,120,0,0" TextWrapping="Wrap" Text="{Binding HelloWorld}" VerticalAlignment="Top" Width="120"/>

    </Grid>
</Window>

Example you can download from here.