我使用了一组名为 ViewboxPath、ViewboxLine、ViewboxPolyline 等的类，它们将 Shape 的拉伸语义更改为更易于处理。我不确定我是否理解你的问题，所以我不知道我的技术是否能解决你的问题。
当我读到它时，要么你想控制这个解决方案将提供的拉伸，要么你想让笔触与图像一起拉伸，Sam 的回答将提供。
无论如何，下面是这些类的代码，这就是你如何使用它们：
<edf:ViewboxPolyline
Viewbox="0 0 1 1" <!-- Actually the default, can be omitted -->
Stretch="Fill" <!-- Also default, can be omitted -->
Stroke="Blue"
Points="0,0 0.2,0 0.2,0.3 0.4,0.3" />
<edf:ViewboxPolygon
Viewbox="0 0 10 10"
Stroke="Blue"
Points="5,0 10,5 5,10 0,5" />
<edf:ViewboxPath
Viewbox="0 0 10 10"
Stroke="Blue"
Data="M10,5 L4,4 L5,10" />
我的Viewbox 形状类的使用与普通形状（Polyline、和）一样Polygon，除了额外参数以及它们默认为. Viewbox 参数在用于指定形状的坐标系中指定应使用或设置而不是使用拉伸的几何图形区域。PathLineViewboxStretch="Fill"FillUniformUniformToFillGeometry.GetBounds
这可以非常精确地控制拉伸，并使单独的形状彼此准确对齐变得容易。
这是我的Viewbox shape classesViewboxShape的实际代码，包括包含通用功能的抽象基类：
public abstract class ViewboxShape : Shape
{
Matrix _transform;
Pen _strokePen;
Geometry _definingGeometry;
Geometry _renderGeometry;
static ViewboxShape()
{
StretchProperty.OverrideMetadata(typeof(ViewboxShape), new FrameworkPropertyMetadata
{
AffectsRender = true,
DefaultValue = Stretch.Fill,
});
}
// The built-in shapes compute stretching using the actual bounds of the geometry.
// ViewBoxShape and its subclasses use this Viewbox instead and ignore the actual bounds of the geometry.
public Rect Viewbox { get { return (Rect)GetValue(ViewboxProperty); } set { SetValue(ViewboxProperty, value); } }
public static readonly DependencyProperty ViewboxProperty = DependencyProperty.Register("Viewbox", typeof(Rect), typeof(ViewboxShape), new UIPropertyMetadata
{
DefaultValue = new Rect(0,0,1,1),
});
// If defined, replaces all the Stroke* properties with a single Pen
public Pen Pen { get { return (Pen)GetValue(PenProperty); } set { SetValue(PenProperty, value); } }
public static readonly DependencyProperty PenProperty = DependencyProperty.Register("Pen", typeof(Pen), typeof(Pen), new UIPropertyMetadata
{
DefaultValue = null
});
// Subclasses override this to define geometry if caching is desired, or just override DefiningGeometry
protected virtual Geometry ComputeDefiningGeometry()
{
return null;
}
// Subclasses can use this PropertyChangedCallback for properties that affect the defining geometry
protected static void OnGeometryChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
var shape = sender as ViewboxShape;
if(shape!=null)
{
shape._definingGeometry = null;
shape._renderGeometry = null;
}
}
// Compute viewport from box & constraint
private Size ApplyStretch(Stretch stretch, Rect box, Size constraint)
{
double uniformScale;
switch(stretch)
{
default:
return new Size(box.Width, box.Height);
case Stretch.Fill:
return constraint;
case Stretch.Uniform:
uniformScale = Math.Min(constraint.Width / box.Width, constraint.Height / box.Height);
break;
case Stretch.UniformToFill:
uniformScale = Math.Max(constraint.Width / box.Width, constraint.Height / box.Height);
break;
}
return new Size(uniformScale * box.Width, uniformScale * box.Height);
}
protected override Size MeasureOverride(Size constraint)
{
// Clear pen cache if settings have changed
if(_strokePen!=null)
if(Pen!=null)
_strokePen = null;
else
if(_strokePen.Thickness != StrokeThickness ||
_strokePen.Brush != Stroke ||
_strokePen.StartLineCap != StrokeStartLineCap ||
_strokePen.EndLineCap != StrokeEndLineCap ||
_strokePen.DashCap != StrokeDashCap ||
_strokePen.LineJoin != StrokeLineJoin ||
_strokePen.MiterLimit != StrokeMiterLimit ||
_strokePen.DashStyle.Dashes != StrokeDashArray ||
_strokePen.DashStyle.Offset != StrokeDashOffset)
_strokePen = null;
_definingGeometry = null;
_renderGeometry = null;
return ApplyStretch(Stretch, Viewbox, constraint);
}
protected override Size ArrangeOverride(Size availableSize)
{
Stretch stretch = Stretch;
Size viewport;
Matrix transform;
// Compute new viewport and transform
if(stretch==Stretch.None)
{
viewport = availableSize;
transform = Matrix.Identity;
}
else
{
Rect box = Viewbox;
viewport = ApplyStretch(stretch, box, availableSize);
double scaleX = viewport.Width / box.Width;
double scaleY = viewport.Height / box.Height;
transform = new Matrix(scaleX, 0, 0, scaleY, -box.Left * scaleX, -box.Top * scaleY);
}
if(_transform!=transform)
{
_transform = transform;
_renderGeometry = null;
InvalidateArrange();
}
return viewport;
}
protected Pen PenOrStroke
{
get
{
if(Pen!=null)
return Pen;
if(_strokePen==null)
_strokePen = new Pen
{
Thickness = StrokeThickness,
Brush = Stroke,
StartLineCap = StrokeStartLineCap,
EndLineCap = StrokeEndLineCap,
DashCap = StrokeDashCap,
LineJoin = StrokeLineJoin,
MiterLimit = StrokeMiterLimit,
DashStyle =
StrokeDashArray.Count==0 && StrokeDashOffset==0 ? DashStyles.Solid :
new DashStyle(StrokeDashArray, StrokeDashOffset),
};
return _strokePen;
}
}
protected Matrix Transform
{
get
{
return _transform;
}
}
protected override Geometry DefiningGeometry
{
get
{
if(_definingGeometry==null)
_definingGeometry = ComputeDefiningGeometry();
return _definingGeometry;
}
}
protected Geometry RenderGeometry
{
get
{
if(_renderGeometry==null)
{
Geometry defining = DefiningGeometry;
if(_transform==Matrix.Identity || defining==Geometry.Empty)
_renderGeometry = defining;
else
{
Geometry geo = defining.CloneCurrentValue();
if(object.ReferenceEquals(geo, defining)) geo = defining.Clone();
geo.Transform = new MatrixTransform(
geo.Transform==null ? _transform : geo.Transform.Value * _transform);
_renderGeometry = geo;
}
}
return _renderGeometry;
}
}
protected override void OnRender(DrawingContext drawingContext)
{
drawingContext.DrawGeometry(Fill, PenOrStroke, RenderGeometry);
}
}
[ContentProperty("Data")]
public class ViewboxPath : ViewboxShape
{
public Geometry Data { get { return (Geometry)GetValue(DataProperty); } set { SetValue(DataProperty, value); } }
public static readonly DependencyProperty DataProperty = DependencyProperty.Register("Data", typeof(Geometry), typeof(ViewboxPath), new UIPropertyMetadata
{
DefaultValue = Geometry.Empty,
PropertyChangedCallback = OnGeometryChanged,
});
protected override Geometry DefiningGeometry
{
get { return Data ?? Geometry.Empty; }
}
}
public class ViewboxLine : ViewboxShape
{
public double X1 { get { return (double)GetValue(X1Property); } set { SetValue(X1Property, value); } }
public double X2 { get { return (double)GetValue(X2Property); } set { SetValue(X2Property, value); } }
public double Y1 { get { return (double)GetValue(Y1Property); } set { SetValue(Y1Property, value); } }
public double Y2 { get { return (double)GetValue(Y2Property); } set { SetValue(Y2Property, value); } }
public static readonly DependencyProperty X1Property = DependencyProperty.Register("X1", typeof(double), typeof(ViewboxLine), new FrameworkPropertyMetadata { PropertyChangedCallback = OnGeometryChanged, AffectsRender = true });
public static readonly DependencyProperty X2Property = DependencyProperty.Register("X2", typeof(double), typeof(ViewboxLine), new FrameworkPropertyMetadata { PropertyChangedCallback = OnGeometryChanged, AffectsRender = true });
public static readonly DependencyProperty Y1Property = DependencyProperty.Register("Y1", typeof(double), typeof(ViewboxLine), new FrameworkPropertyMetadata { PropertyChangedCallback = OnGeometryChanged, AffectsRender = true });
public static readonly DependencyProperty Y2Property = DependencyProperty.Register("Y2", typeof(double), typeof(ViewboxLine), new FrameworkPropertyMetadata { PropertyChangedCallback = OnGeometryChanged, AffectsRender = true });
protected override Geometry ComputeDefiningGeometry()
{
return new LineGeometry(new Point(X1, Y1), new Point(X2, Y2));
}
}
[ContentProperty("Points")]
public class ViewboxPolyline : ViewboxShape
{
public ViewboxPolyline()
{
Points = new PointCollection();
}
public PointCollection Points { get { return (PointCollection)GetValue(PointsProperty); } set { SetValue(PointsProperty, value); } }
public static readonly DependencyProperty PointsProperty = DependencyProperty.Register("Points", typeof(PointCollection), typeof(ViewboxPolyline), new FrameworkPropertyMetadata
{
PropertyChangedCallback = OnGeometryChanged,
AffectsRender = true,
});
public FillRule FillRule { get { return (FillRule)GetValue(FillRuleProperty); } set { SetValue(FillRuleProperty, value); } }
public static readonly DependencyProperty FillRuleProperty = DependencyProperty.Register("FillRule", typeof(FillRule), typeof(ViewboxPolyline), new FrameworkPropertyMetadata
{
DefaultValue = FillRule.EvenOdd,
PropertyChangedCallback = OnGeometryChanged,
AffectsRender = true,
});
public bool CloseFigure { get { return (bool)GetValue(CloseFigureProperty); } set { SetValue(CloseFigureProperty, value); } }
public static readonly DependencyProperty CloseFigureProperty = DependencyProperty.Register("CloseFigure", typeof(bool), typeof(ViewboxPolyline), new FrameworkPropertyMetadata
{
DefaultValue = false,
PropertyChangedCallback = OnGeometryChanged,
AffectsRender = true,
});
protected override Geometry ComputeDefiningGeometry()
{
PointCollection points = Points;
if(points.Count<2) return Geometry.Empty;
var geometry = new StreamGeometry { FillRule = FillRule };
using(var context = geometry.Open())
{
context.BeginFigure(Points[0], true, CloseFigure);
context.PolyLineTo(Points.Skip(1).ToList(), true, true);
}
return geometry;
}
}
public class ViewboxPolygon : ViewboxPolyline
{
static ViewboxPolygon()
{
CloseFigureProperty.OverrideMetadata(typeof(ViewboxPolygon), new FrameworkPropertyMetadata
{
DefaultValue = true,
});
}
}
享受！