The BorderBrush property of the TextBox sets a brush to draw the border of a TextBox. You may use any brush to fill the border. The code snippet in Listing 3 uses a linear gradient brush to draw the border with a combination of red and blue color.
<TextBox.BorderBrush>
<LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
<GradientStop Color="Blue" Offset="0" />
<GradientStop Color="Red" Offset="1.0" />
</LinearGradientBrush>
</TextBox.BorderBrush>
The Background and Foreground properties of the TextBox set the background and foreground colors of a TextBox. You may use any brush to fill the border. The following code snippet uses linear gradient brushes to draw the background and foreground of a TextBox.
<TextBox.Background>
<LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
<GradientStop Color="Blue" Offset="0.1" />
<GradientStop Color="Orange" Offset="0.25" />
<GradientStop Color="Green" Offset="0.75" />
<GradientStop Color="Red" Offset="1.0" />
</LinearGradientBrush>
</TextBox.Background>
<TextBox.Foreground>
<LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
<GradientStop Color="Orange" Offset="0.25" />
<GradientStop Color="White" Offset="1.0" />
</LinearGradientBrush>
</TextBox.Foreground>