仿Word的支持横轴竖轴的WPF 标尺

在WPF中可以使用Adorner来实现类似Word中的标尺功能。Adorner是一种覆盖在UI元素上的装饰性控件，可以用来实现各种效果，比如拖拽、调整大小、标记、提示等。

以下是一个简单的示例代码，可以实现支持横轴和竖轴的标尺：

1. 创建一个自定义控件`RulerControl`，用于显示标尺。

public class RulerControl : Control
{
    private AdornerLayer adornerLayer;

    public RulerControl()
    {
        // 创建AdornerLayer
        adornerLayer = AdornerLayer.GetAdornerLayer(this);
        adornerLayer.Add(new RulerAdorner(this));
    }
}

2. 创建一个自定义Adorner`RulerAdorner`，用于在`RulerControl`上绘制标尺。

public class RulerAdorner : Adorner
{
    private Pen pen;
    private Typeface typeface;
    private double dpiX, dpiY;
    private double pixelSizeX, pixelSizeY;
    private double tickInterval;
    private double tickLength;

    public RulerAdorner(UIElement adornedElement) : base(adornedElement)
    {
        // 初始化画笔和字体
        pen = new Pen(Brushes.Black, 1);
        typeface = new Typeface("Arial");

        // 获取屏幕DPI
        dpiX = VisualTreeHelper.GetDpi(adornedElement).PixelsPerInchX;
        dpiY = VisualTreeHelper.GetDpi(adornedElement).PixelsPerInchY;

        // 计算每个像素的实际大小
        pixelSizeX = 25.4 / dpiX;
        pixelSizeY = 25.4 / dpiY;

        // 计算刻度间隔和刻度线长度
        tickInterval = pixelSizeX * 10; // 每10个像素显示一个刻度线
        tickLength = pixelSizeY * 5; // 刻度线长度为5个像素
    }

    protected override void OnRender(DrawingContext drawingContext)
    {
        base.OnRender(drawingContext);

        // 获取AdornedElement的宽度和高度
        double width = AdornedElement.RenderSize.Width;
        double height = AdornedElement.RenderSize.Height;

        // 绘制横轴标尺
        for (double x = 0; x <= width; x += tickInterval)
        {
            double tickY1 = 0;
            double tickY2 = tickLength;

            Point p1 = new Point(x, tickY1);
            Point p2 = new Point(x, tickY2);
            drawingContext.DrawLine(pen, p1, p2);

            if (x % (10 * tickInterval) == 0)
            {
                string text = (x / tickInterval / 10).ToString();
                FormattedText ft = new FormattedText(text, CultureInfo.CurrentCulture, FlowDirection.LeftToRight, typeface, 10, Brushes.Black);
                double textX = x - ft.Width / 2;
                double textY = tickY2 + 5;

                drawingContext.DrawText(ft, new Point(textX, textY));
            }
        }

        // 绘制竖轴标尺
        for (double y = 0; y <= height; y += tickInterval)
        {
            double tickX1 = 0;
            double tickX2 = tickLength;

            Point p1 = new Point(tickX1, y);
            Point p2 = new Point(tickX2, y);
            drawingContext.DrawLine(pen, p1, p2);

            if (y % (10 * tickInterval) == 0)
            {
                string text = (y / tickInterval / 10).ToString();
                FormattedText ft = new FormattedText(text, CultureInfo.CurrentCulture, FlowDirection.LeftToRight, typeface, 10, Brushes.Black);
                double textX = tickX2 + 5;
                double textY = y - ft.Height / 2;

                drawingContext.DrawText(ft, new Point(textX, textY));
            }
        }
    }
}

3. 在MainWindow中使用`RulerControl`。

<Window x:Class="RulerDemo.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <RulerControl Grid.Row="0" Height="20"/>

        <Grid Grid.Row="1">
            ...
        </Grid>
    </Grid>
</Window>

这样就可以在MainWindow中显示一个支持横轴和竖轴的标尺了。注意，需要为`RulerControl`设置高度，以便Adorner能够正确地定位和绘制。