Question

I used an example I found online to create a custom grid control. It allows me to place the kind of gridlines that I want to make a calender. But now When I go to set the background it stops my custom gridlines from displaying.

I know it’s b/c the OnRender is being called first and then the background which is getting rid of my custom settings. I tied getting rid of the override on OnRender but still no luck. So my question is how can I make a custom background that will still allow the gridlines to be shown.

This is the background I want on my custom control: If I try to add this to the custom control my gridlines disappear.

    <Grid.Background>
        <RadialGradientBrush>
            <GradientStop Color="#FFC3D6F5" Offset="0" />
            <GradientStop Color="#FFEFF5FF" Offset="1" />
        </RadialGradientBrush>
    </Grid.Background>

This is the custom control I found online. It only sets customgridline properties. I need a custom background property now. It’s a little harder because my background is not a solid color.

namespace Camp_
{    
public class GridControl : Grid
{

    #region Properties
    public bool ShowCustomGridLines
    {
        get { return (bool)GetValue(ShowCustomGridLinesProperty); }
        set { SetValue(ShowCustomGridLinesProperty, value); }
    }



    public static readonly DependencyProperty ShowCustomGridLinesProperty =
        DependencyProperty.Register("ShowCustomGridLines", typeof(bool), typeof(GridControl), new UIPropertyMetadata(false));

    public Brush GridLineBrush
    {
        get { return (Brush)GetValue(GridLineBrushProperty); }
        set { SetValue(GridLineBrushProperty, value); }
    }


    public static readonly DependencyProperty GridLineBrushProperty =
        DependencyProperty.Register("GridLineBrush", typeof(Brush), typeof(GridControl), new UIPropertyMetadata(Brushes.Black));



    public double GridLineThickness
    {
        get { return (double)GetValue(GridLineThicknessProperty); }
        set { SetValue(GridLineThicknessProperty, value); }
    }

    public static readonly DependencyProperty GridLineThicknessProperty =
        DependencyProperty.Register("GridLineThickness", typeof(double), typeof(GridControl), new UIPropertyMetadata(1.0));
    #endregion

    protected override void OnRender(DrawingContext dc)
    {  

        if (ShowCustomGridLines)
        {

            foreach (var rowDefinition in RowDefinitions)
            {
                dc.DrawLine(new Pen(GridLineBrush, GridLineThickness), new Point(0, rowDefinition.Offset), new Point(ActualWidth, rowDefinition.Offset));
            }

            foreach (var columnDefinition in ColumnDefinitions)
            {
                dc.DrawLine(new Pen(GridLineBrush, GridLineThickness), new Point(columnDefinition.Offset, 0), new Point(columnDefinition.Offset, ActualHeight));
            } 
            dc.DrawRectangle(Brushes.Transparent, new Pen(GridLineBrush, GridLineThickness), new Rect(0, 0, ActualWidth, ActualHeight));
        }
        base.OnRender(dc);
    }

    static GridControl()
    {
        DefaultStyleKeyProperty.OverrideMetadata(typeof(GridControl), new FrameworkPropertyMetadata(typeof(GridControl)));
    }
}
}

And the XAML:

<customgridcontrol:GridControl ShowCustomGridLines="True" GridLineBrush="CornflowerBlue" ShowGridLines="False" >
                    <Grid.RowDefinitions>
                        <RowDefinition />
                        <RowDefinition />
                        <RowDefinition />
                        <RowDefinition />
                        <RowDefinition />
                        <RowDefinition />
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition />
                        <ColumnDefinition />
                        <ColumnDefinition />
                        <ColumnDefinition />
                        <ColumnDefinition />
                        <ColumnDefinition />
                        <ColumnDefinition />
                    </Grid.ColumnDefinitions>
</customgridcontrol:GridControl>

Answer 1

I think you only have to set the standard background property in the xaml code like this:

<customgridcontrol:GridControl ShowCustomGridLines="True" GridLineBrush="CornflowerBlue" ShowGridLines="False" Background="Binding{ StaticResource BrushYouWantTo" >
                <Grid.RowDefinitions>
                    <RowDefinition />
                    <RowDefinition />
                    <RowDefinition />
                    <RowDefinition />
                    <RowDefinition />
                    <RowDefinition />
                </Grid.RowDefinitions>
                <Grid.ColumnDefinitions>
                    <ColumnDefinition />
                    <ColumnDefinition />
                    <ColumnDefinition />
                    <ColumnDefinition />
                    <ColumnDefinition />
                    <ColumnDefinition />
                    <ColumnDefinition />
                </Grid.ColumnDefinitions>
</customgridcontrol:GridControl>

The “brush you want to” must set as resource in the xaml code like this:

<Window.Resources>
   <RadialGradientBrush Name="BrushYouWantTo">
      <GradientStop Color="#FFC3D6F5" Offset="0" />
      <GradientStop Color="#FFEFF5FF" Offset="1" />
   </RadialGradientBrush>
</Window.Resources>

But if you want to change the background color while the program is running you need a dependency property and a event handler who reload the gui. To use this event handler you must define it with a

new UIPropertyMetadata(CustomGridBackgroundChanged)

And the event handler definition can look like this:

  private static void CustomGridBackgroundChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
  {
     WindowName win = (WindowName)sender;
     if (win.PropertyChanged != null)
     {
        // at this place the gui will be reloaded
        win.PropertyChanged(win, new PropertyChangedEventArgs(null));
     }
  }

It is only an idea so i dont really know if it work in practice…
But i hope it help you a little bit