[c#] How could I put a border on my grid control in WPF?

How do I put a border on my grid in C#/WPF?

This is what I would like it to be, but puts a border around the whole thing instead of the grid control I put in my application.

<Grid>
    <Border BorderBrush="Black" BorderThickness="2">
        <Grid Height="166" HorizontalAlignment="Left" Margin="12,12,0,0" Name="grid1" VerticalAlignment="Top" Width="479" Background="#FFF2F2F2" />
    </Border>
... and so on ...

If someone is interested in the similar problem, but is not working with XAML, here's my solution:

var B1 = new Border();
B1.BorderBrush = Brushes.Black;
B1.BorderThickness = new Thickness(0, 1, 0, 0); // You can specify here which borders do you want
YourPanel.Children.Add(B1);

This is my solution, wish useful for you:

public class Sheet : Grid
{
    public static readonly DependencyProperty BorderBrushProperty = DependencyProperty.Register(nameof(BorderBrush), typeof(Brush), typeof(Sheet), new FrameworkPropertyMetadata(Brushes.Transparent, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender, OnBorderBrushChanged));

    public static readonly DependencyProperty BorderThicknessProperty = DependencyProperty.Register(nameof(BorderThickness), typeof(double), typeof(Sheet), new FrameworkPropertyMetadata(1D, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender, OnBorderThicknessChanged, CoerceBorderThickness));
    public static readonly DependencyProperty CellSpacingProperty = DependencyProperty.Register(nameof(CellSpacing), typeof(double), typeof(Sheet), new FrameworkPropertyMetadata(0D, FrameworkPropertyMetadataOptions.AffectsMeasure | FrameworkPropertyMetadataOptions.AffectsRender, OnCellSpacingChanged, CoerceCellSpacing));

    public Brush BorderBrush
    {
        get => this.GetValue(BorderBrushProperty) as Brush;
        set => this.SetValue(BorderBrushProperty, value);
    }

    public double BorderThickness
    {
        get => (double)this.GetValue(BorderThicknessProperty);
        set => this.SetValue(BorderThicknessProperty, value);
    }

    public double CellSpacing
    {
        get => (double)this.GetValue(CellSpacingProperty);
        set => this.SetValue(CellSpacingProperty, value);
    }

    protected override Size ArrangeOverride(Size arrangeSize)
    {
        Size size = base.ArrangeOverride(arrangeSize);
        double border = this.BorderThickness;
        double doubleBorder = border * 2D;
        double spacing = this.CellSpacing;
        double halfSpacing = spacing * 0.5D;
        if (border > 0D || spacing > 0D)
        {
            foreach (UIElement child in this.InternalChildren)
            {
                this.GetChildBounds(child, out double left, out double top, out double width, out double height);

                left += halfSpacing + border;
                top += halfSpacing + border;
                height -= spacing + doubleBorder;
                width -= spacing + doubleBorder;

                if (width < 0D)
                {
                    width = 0D;
                }

                if (height < 0D)
                {
                    height = 0D;
                }

                left -= left % 0.5D;
                top -= top % 0.5D;
                width -= width % 0.5D;
                height -= height % 0.5D;

                child.Arrange(new Rect(left, top, width, height));
            }

            if (border > 0D && this.BorderBrush != null)
            {
                this.InvalidateVisual();
            }
        }

        return size;
    }
    
    protected override void OnRender(DrawingContext dc)
    {
        base.OnRender(dc);

        if (this.BorderThickness > 0D && this.BorderBrush != null)
        {
            if (this.CellSpacing == 0D)
            {
                this.DrawCollapsedBorder(dc);
            }
            else
            {
                this.DrawSeperatedBorder(dc);
            }
        }
    }

    private void DrawSeperatedBorder(DrawingContext dc)
    {
        double spacing = this.CellSpacing;
        double halfSpacing = spacing * 0.5D;


        #region draw border
        Pen pen = new Pen(this.BorderBrush, this.BorderThickness);
        UIElementCollection children = this.InternalChildren;
        foreach (UIElement child in children)
        {
            this.GetChildBounds(child, out double left, out double top, out double width, out double height);
            left += halfSpacing;
            top += halfSpacing;
            width -= spacing;
            height -= spacing;

            dc.DrawRectangle(null, pen, new Rect(left, top, width, height));
        }
        #endregion
    }

    private void DrawCollapsedBorder(DrawingContext dc)
    {
        RowDefinitionCollection rows = this.RowDefinitions;
        ColumnDefinitionCollection columns = this.ColumnDefinitions;
        int rowCount = rows.Count;
        int columnCount = columns.Count;
        const byte BORDER_LEFT = 0x08;
        const byte BORDER_TOP = 0x04;
        const byte BORDER_RIGHT = 0x02;
        const byte BORDER_BOTTOM = 0x01;
        byte[,] borderState = new byte[rowCount, columnCount];
        int column = columnCount - 1;
        int columnSpan;
        int row = rowCount - 1;
        int rowSpan;
        #region generate main border data
        for (int i = 0; i < rowCount; i++)
        {
            borderState[i, 0] = BORDER_LEFT;
            borderState[i, column] = BORDER_RIGHT;
        }

        for (int i = 0; i < columnCount; i++)
        {
            borderState[0, i] |= BORDER_TOP;
            borderState[row, i] |= BORDER_BOTTOM;
        }
        #endregion

        #region generate child border data
        UIElementCollection children = this.InternalChildren;
        foreach (UIElement child in children)
        {
            this.GetChildLayout(child, out row, out rowSpan, out column, out columnSpan);
            for (int i = 0; i < rowSpan; i++)
            {
                borderState[row + i, column] |= BORDER_LEFT;
                borderState[row + i, column + columnSpan - 1] |= BORDER_RIGHT;
            }
            for (int i = 0; i < columnSpan; i++)
            {
                borderState[row, column + i] |= BORDER_TOP;
                borderState[row + rowSpan - 1, column + i] |= BORDER_BOTTOM;
            }
        }
        #endregion

        #region draw border
        Pen pen = new Pen(this.BorderBrush, this.BorderThickness);
        double left;
        double top;
        double width, height;


        for (int r = 0; r < rowCount; r++)
        {
            RowDefinition v = rows[r];
            top = v.Offset;
            height = v.ActualHeight;
            for (int c = 0; c < columnCount; c++)
            {
                byte state = borderState[r, c];

                ColumnDefinition h = columns[c];
                left = h.Offset;
                width = h.ActualWidth;
                if ((state & BORDER_LEFT) == BORDER_LEFT)
                {
                    dc.DrawLine(pen, new Point(left, top), new Point(left, top + height));
                }
                if ((state & BORDER_TOP) == BORDER_TOP)
                {
                    dc.DrawLine(pen, new Point(left, top), new Point(left + width, top));
                }
                if ((state & BORDER_RIGHT) == BORDER_RIGHT && (c + 1 >= columnCount || (borderState[r, c + 1] & BORDER_LEFT) == 0))
                {
                    dc.DrawLine(pen, new Point(left + width, top), new Point(left + width, top + height));
                }
                if ((state & BORDER_BOTTOM) == BORDER_BOTTOM && (r + 1 >= rowCount || (borderState[r + 1, c] & BORDER_TOP) == 0))
                {
                    dc.DrawLine(pen, new Point(left, top + height), new Point(left + width, top + height));
                }
            }

        }
        #endregion
    }

    private void GetChildBounds(UIElement child, out double left, out double top, out double width, out double height)
    {
        ColumnDefinitionCollection columns = this.ColumnDefinitions;
        RowDefinitionCollection rows = this.RowDefinitions;
        int rowCount = rows.Count;

        int row = (int)child.GetValue(Grid.RowProperty);
        if (row >= rowCount)
        {
            row = rowCount - 1;
        }

        int rowSpan = (int)child.GetValue(Grid.RowSpanProperty);
        if (row + rowSpan > rowCount)
        {
            rowSpan = rowCount - row;
        }
        int columnCount = columns.Count;

        int column = (int)child.GetValue(Grid.ColumnProperty);
        if (column >= columnCount)
        {
            column = columnCount - 1;
        }

        int columnSpan = (int)child.GetValue(Grid.ColumnSpanProperty);
        if (column + columnSpan > columnCount)
        {
            columnSpan = columnCount - column;
        }

        left = columns[column].Offset;
        top = rows[row].Offset;
        ColumnDefinition right = columns[column + columnSpan - 1];
        width = right.Offset + right.ActualWidth - left;
        RowDefinition bottom = rows[row + rowSpan - 1];
        height = bottom.Offset + bottom.ActualHeight - top;
        if (width < 0D)
        {
            width = 0D;
        }

        if (height < 0D)
        {
            height = 0D;
        }

    }
    private void GetChildLayout(UIElement child, out int row, out int rowSpan, out int column, out int columnSpan)
    {
        int rowCount = this.RowDefinitions.Count;

        row = (int)child.GetValue(Grid.RowProperty);
        if (row >= rowCount)
        {
            row = rowCount - 1;
        }

        rowSpan = (int)child.GetValue(Grid.RowSpanProperty);
        if (row + rowSpan > rowCount)
        {
            rowSpan = rowCount - row;
        }
        int columnCount = this.ColumnDefinitions.Count;

        column = (int)child.GetValue(Grid.ColumnProperty);
        if (column >= columnCount)
        {
            column = columnCount - 1;
        }

        columnSpan = (int)child.GetValue(Grid.ColumnSpanProperty);
        if (column + columnSpan > columnCount)
        {
            columnSpan = columnCount - column;
        }
    }

    private static void OnBorderBrushChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
    {
        if (d is UIElement element)
        {
            element.InvalidateVisual();
        }
    }

    private static void OnBorderThicknessChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
    {
        if (d is UIElement element)
        {
            element.InvalidateArrange();
        }
    }

    private static void OnCellSpacingChanged(DependencyObject d, DependencyPropertyChangedEventArgs args)
    {
        if (d is UIElement element)
        {
            element.InvalidateArrange();
        }
    }

    private static object CoerceBorderThickness(DependencyObject d, object baseValue)
    {
        if (baseValue is double value)
        {
            return value < 0D || double.IsNaN(value) || double.IsInfinity(value) ? 0D : value;
        }

        return 0D;
    }
    private static object CoerceCellSpacing(DependencyObject d, object baseValue)
    {
        if (baseValue is double value)
        {
            return value < 0D || double.IsNaN(value) || double.IsInfinity(value) ? 0D : value;
        }

        return 0D;
    }
}

a demo:

I think your problem is that the margin should be specified in the border tag and not in the grid.

If nesting your grid in a border control

<Border>
    <Grid>
    </Grid>
</Border>

does not do what you want, then you are going to have to make your own control template for the grid (or border) that DOES do what you want.

<Grid x:Name="outerGrid">
    <Grid x:Name="innerGrid">
        <Border BorderBrush="#FF179AC8" BorderThickness="2" />
        <other stuff></other stuff>
        <other stuff></other stuff>
    </Grid>
</Grid>

This code Wrap a border inside the "innerGrid"

This is a later answer that works for me, if it may be of use to anyone in the future. I wanted a simple border around all four sides of the grid and I achieved it like so...

<DataGrid x:Name="dgDisplay" Margin="5" BorderBrush="#1266a7" BorderThickness="1"...