WPF Drawing Wheel Color Picker?-CodePudding

I'm have try drawing color picker by Ellipse LinearGradientBrush.

<Ellipse Width="200" Height="200">
    <Ellipse.Fill>
        <VisualBrush TileMode="None">
            <VisualBrush.Visual>
                <Canvas Width="1" Height="1" SnapsToDevicePixels="True">
                    <Rectangle Width="1" Height="1" SnapsToDevicePixels="True">
                        <Rectangle.Fill>
                            <LinearGradientBrush StartPoint="0,0" EndPoint="1,0">
                                <LinearGradientBrush.GradientStops>
                                   <GradientStop Color="#FF0000" Offset="0" />
                                    <GradientStop Color="#FFFF00" Offset="0.167" />
                                    <GradientStop Color="#00FF00" Offset="0.333" />
                                    <GradientStop Color="#00FFFF" Offset="0.5" />
                                    <GradientStop Color="#0000FF" Offset="0.667" />
                                    <GradientStop Color="#FF00FF" Offset="0.833" />
                                    <GradientStop Color="#FF0000" Offset="1" />
                                </LinearGradientBrush.GradientStops>
                            </LinearGradientBrush>
                        </Rectangle.Fill>
                        <Rectangle.OpacityMask>
                            <LinearGradientBrush StartPoint="0,0" EndPoint="0,1">
                                <LinearGradientBrush.GradientStops>
                                    <GradientStop Color="#FFFFFFFF" Offset="0"/>
                                    <GradientStop Color="#00FFFFFF" Offset="1"/>
                                </LinearGradientBrush.GradientStops>
                            </LinearGradientBrush>
                        </Rectangle.OpacityMask>
                    </Rectangle>
                </Canvas>
            </VisualBrush.Visual>
        </VisualBrush>
    </Ellipse.Fill>
</Ellipse>

It's just like this:

But How can drawing a colorpicker have multiple color and like the scattered out color like a this.

I have not idea. please any one help.

CodePudding user response：

Personally, I'd just use a background texture. @Jim Foye is right though, it's very easy to do with a pixel shader:

make sure you've got the fxc shader compiler installed (