Specific control for a specific DataType

Answer 1

<Window x:Class="MiscSamples.DataTemplates"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        Title="DataTemplates"
        Height="300"
        Width="300">
  <Window.Resources>

    <!-- DataTemplate for strings -->
    <DataTemplate DataType="{x:Type sys:String}">
      <TextBox Text="{Binding Path=.}" />
    </DataTemplate>

    <!-- DataTemplate for DateTimes -->
    <DataTemplate DataType="{x:Type sys:DateTime}">
      <DataTemplate.Resources>
        <DataTemplate DataType="{x:Type sys:String}">
          <TextBlock Text="{Binding Path=.}" />
        </DataTemplate>
      </DataTemplate.Resources>
      <DatePicker SelectedDate="{Binding Path=.}" />
    </DataTemplate>


    <!-- DataTemplate for Int32 -->
    <DataTemplate DataType="{x:Type sys:Int32}">
      <Slider Maximum="100"
              Minimum="0"
              Value="{Binding Path=.}"
              Width="100" />
    </DataTemplate>
  </Window.Resources>
  <ListBox ItemsSource="{Binding}" />
</Window>

Code Behind:

 public partial class DataTemplates : Window
    {
        public DataTemplates()
        {
            InitializeComponent();

            var myList = new List<object>();
            myList.Add(DateTime.Now);
            myList.Add(50);
            myList.Add("Hello World");

            DataContext = myList;
        }
    }

Result:

As you can see, there's no reason at all to use code to manipulate UI elements in WPF (except some very very specific cases)

Edit:

Note that you don't usually create a DataTemplate for classes inside the System namespace (such as System.String. This is only to give you an example. If you really needed this you would probably have to create a ViewModel for each type.