Change color of WPF button using code

Question

I have WPF triangle button which is made using Polygon-geometry:

<UserControl x:Class="Formats.Triangle_Down"
         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
         xmlns:local="clr-namespace:Formats"
         mc:Ignorable="d" Height="100" Width="100">
<Grid Margin="0,0,10,10">
    <Grid.RowDefinitions>
        <RowDefinition Height="7*"/>
        <RowDefinition Height="11*"/>
    </Grid.RowDefinitions>
    <Button Background="Transparent" Content="Button" Foreground="Transparent" Margin="0,0,50,0">
        <Button.Template>
            <ControlTemplate TargetType="Button">
                <Grid Background="{TemplateBinding Background}">
                    <Polygon x:Name="triangle" Points="10,10 20,30 30,10"  Stroke="Lime"
                     StrokeThickness="2" Fill="Lime" Margin="0,0,-91,-85">
                        </Polygon>
                    </Grid>
        </Button.Template>
    </Button>
</Grid>

So my question is: how can I change Background color and Borderbrush of my Button using C# code? When I use this:

button.Background = System.Windows.Media.Brushes.Red;

nothing changes (if I have not mistaken, because it doesn't change filling of polygon). I know the way to change color using "border"

<Border Background="{TemplateBinding Background}">
<Button.Content>
</Border>

But it doesn't suit me 'cause form of my button is triangle.

So, how can I solve this problem?

https://stackoverflow.com/questions/33151663/button-color-wpf/33151803#33151803 — Salah Akbari, Oct 12 '17 at 07:20

score 0 · Accepted Answer · answered Oct 12 '17 at 07:24

In your template you put your polygon inside grid and bind that grid background to Button.Background, while hardcoding color of your polygon to Lime. That way you cannot change color of polygon later. Instead - bind polygon colors to Button.Background:

<Button Background="Lime"
        Content="Button"
        Foreground="Transparent"
        Margin="0,0,50,0">
    <Button.Template>
        <ControlTemplate TargetType="Button">
            <Polygon x:Name="triangle"
                     Points="10,10 20,30 30,10"
                     Stroke="{TemplateBinding Background}"
                     StrokeThickness="2"
                     Fill="{TemplateBinding Background}"
                     Margin="0,0,-91,-85"></Polygon>
        </ControlTemplate>
    </Button.Template>
</Button>

Then changing Button.Background will change colors of polygon.

Change color of WPF button using code

1 Answers1