WPF custom shape control - wpf

Question

I was wondering if it is possible to make a custom shape custom control.
I need to make control which contains textbox, however the control must have a shape of triangle or sth more sophisticated than regular rectangle/square.

Answer 1

Short answer is yes.
Long answer is reading up on WPF Control Styles:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="WpfApplication1.MainWindow"
x:Name="Window"
Title="MainWindow"
Width="640"
Height="480">
<Window.Resources>
<Style x:Key="TextBoxSample" TargetType="{x:Type TextBox}">
<Setter Property="FontWeight" Value="Bold"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type TextBox}">
<Grid>
<Ellipse
x:Name="Border"
Stroke="#FF393785"
StrokeThickness="2"
>
<Ellipse.Fill>
<RadialGradientBrush GradientOrigin="0.25,0.25" RadiusY="0.75" RadiusX="0.75">
<GradientStop Color="White" Offset="0.2"/>
<GradientStop Color="#FF2EC452" Offset="0.5"/>
<GradientStop Color="#FF606060" Offset="1"/>
</RadialGradientBrush>
</Ellipse.Fill>
</Ellipse>
<!-- The implementation places the Content into the ScrollViewer. It must be named PART_ContentHost for the control to function -->
<ScrollViewer
x:Name="PART_ContentHost"
Background="Transparent"
HorizontalAlignment="Center"
VerticalAlignment="Center"
/>
</Grid>
<ControlTemplate.Triggers>
<Trigger Property="IsEnabled" Value="False">
<Setter Property="Fill" Value="#000" TargetName="Border"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Window.Resources>
<Grid x:Name="LayoutRoot">
<TextBox
Style="{StaticResource TextBoxSample}"
VerticalAlignment="Center"
HorizontalAlignment="Center"
Text="TextBox"
Width="180"
Height="180"
/>
</Grid>
</Window>