Je suis tombé sur ce problème un certain temps . À l'époque, j'ai trouvé la solution repka proposée, mais elle était insatisfaite parce que c'était relativement complexe et pas aussi efficace que je l'aurais souhaité.
Je résolu le problème en codant un ensemble de classes simples de forme ViewBox qui fonctionnent exactement comme la construction dans Path, Line, Polyline et Polygon les classes, sauf qu'ils le rendent facile à obtenir l'étirement de travailler comme vous le voulez .
Mes cours sont ViewboxPath, ViewboxLine, ViewboxPolyline et ViewboxPolygon, et ils sont utilisés comme ceci:
<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" />
Comme vous pouvez le voir, mes les classes ViewBox de forme sont utilisés comme des formes normales (Polyline, Polygon , Path et Line) à l'exception du paramètre supplémentaire Viewbox et du fait qu'ils sont par défaut Stretch="Fill".Le paramètre Viewbox spécifie, dans le système de coordonnées utilisé pour spécifier la forme, la zone de la géométrie qui doit être étendue en utilisant les paramètres Fill, Uniform ou UniformToFill, au lieu d'utiliser Geometry.GetBounds.
Cela permet un contrôle très précis de l'étirement et facilite l'alignement des formes séparées les unes par rapport aux autres.
Voici le code réel pour mes cours ViewBox de forme, y compris la classe de base abstraite ViewboxShape qui contient des fonctionnalités communes:
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(ViewboxShape));
// 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,
});
}
}
Enjoy!
Fonctionne parfaitement, merci! Je suis actuellement en train d'utiliser les fonctionnalités de création de graphiques WPF Toolkit, mais c'est bon à savoir avec GeometryDrawing pour le futur. Merci. – Derek
Ou vous pouvez consulter mes classes de forme Viewbox (voir le code ci-dessous) –