I have created a c# windows application and written 75% of the code. The program allows the user to create a flow chart, and will shade the flow chart shapes according to their status. I wanted them to become 3d buttons such as from the website Webdesign.org
Rather than create a PNG for each button, I wanted to create them in C# using brushes or other technique, such as:
// Create solid brush.
SolidBrush blueBrush = new SolidBrush(Color.Blue);
// Create points that define polygon.
PointF point1 = new PointF(50.0F, 50.0F);
PointF point2 = new PointF(100.0F, 25.0F);
PointF point3 = new PointF(200.0F, 5.0F);
PointF point4 = new PointF(250.0F, 50.0F);
PointF point5 = new PointF(300.0F, 100.0F);
PointF point6 = new PointF(350.0F, 200.0F);
PointF point7 = new PointF(250.0F, 250.0F);
PointF[] curvePoints = {point1, point2, point3, point4, point5, point6, point7};
// Define fill mode.
FillMode newFillMode = FillMode.Winding;
// Fill polygon to screen.
e.Graphics.FillPolygon(blueBrush, curvePoints, newFillMode);
I know WPF has radial gradients, but can I do something simular in CGI?
Unlike WPF, GDI+/WinForms does not have a RadialGradientBrush. However you can achieve the same effect using a PathGradientBrush.
Here's an example:
Rectangle bounds = ...;
using (var ellipsePath = new GraphicsPath())
{
ellipsePath.AddEllipse(bounds);
using (var brush = new PathGradientBrush(ellipsePath))
{
brush.CenterPoint = new PointF(bounds.Width/2f, bounds.Height/2f);
brush.CenterColor = Color.White;
brush.SurroundColors = new[] { Color.Red };
brush.FocusScales = new PointF(0, 0);
e.Graphics.FillRectangle(brush, bounds);
}
}
The PathGradientBrush has lots of properties to experiment with to ensure you get the effect you're after.
Take a look at this Codeproject article, and then at the Path gradient.
Related
I would like to know how can I draw an arc in C# , I'm trying using DrawEllipse but it doesn't work and it give wrong drawing.
However, I have searched for a method to draw an arc in the Class DrawingContext but I didn't find it.
DrawingVisual d = new DrawingVisual();
System.Windows.Media.Pen pen = new System.Windows.Media.Pen();
DrawingContext drawingContext = d.RenderOpen();
pen.Brush = System.Windows.Media.Brushes.Black;
System.Windows.Point center = new System.Windows.Point();
center.X = 0.4;
center.Y = 0.5;
drawingContext.DrawEllipse(System.Windows.Media.Brushes.White, pen, center, 4,4);
drawingContext.Close();
canvas.Children.Add(new VisualHost { Visual = d });
You would have to draw a PathGeometry or a StreamGeometry that contains an arc segment, like the following circular arc of radius 100 from (100,100) to (200,200):
var visual = new DrawingVisual();
var pen = new Pen(Brushes.Black, 1);
using (var dc = visual.RenderOpen())
{
var figure = new PathFigure
{
StartPoint = new Point(100, 100) // start point
};
figure.Segments.Add(new ArcSegment
{
Point = new Point(200, 200), // end point
Size = new Size(100, 100), // radii
SweepDirection = SweepDirection.Clockwise
});
var geometry = new PathGeometry();
geometry.Figures.Add(figure);
dc.DrawGeometry(null, pen, geometry);
}
Back here. Is there any way to improve the quality of the Arc?
I'm using e.Graphics.SmoothingMode = SmoothingMode.AntiAlias
This is the piece of code that creates the arc:
using (GraphicsPath gp = new GraphicsPath())
{
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
gp.Reset();
gp.AddPie(_OuterRectangle, (float)_Properties.Origin, (float)_Properties.GaugeType);
gp.Reverse();
gp.AddPie(_InnerRectangle, (float)_Properties.Origin, (float)_Properties.GaugeType);
gp.Reverse();
pArea.SetClip(gp);
using (Pen oPen = new Pen(this.ForeColor, 2f))
{
e.Graphics.DrawPath(oPen, gp);
}
e.Graphics.SetClip(ClientRectangle);
}
Thanks in advance.
EDIT:
I've did what LarsTech proposed and now the quality is perfect, but I'm not having the figure I need:
OuterRectangle: is the ClientRectangle area, that I'm manipulating it to make Width and Height the same lenght;
InnerRectangle: is 2/3ths of the ClientRectangle area, ergo, of the OuterRectangle;
Properties.Origin: is the angle where the arc starts. I have it in an enumerator as Cardinal Points, where North is 270, East is 0,
and so. In case of the figure, is SouthWest, 135 degrees;
Properties.GaugeType: is another enumerator that says if is Complete = 360, Half = 180, Quarter = 90, so with that I can determine the sweep angle. In case of the figure is ThreeQuarter, 270 degrees.
The problem:
When clipping a region of the current Graphics (Graphics.SetClip method), the resulting drawing loses quality, because the antialiasing effect generated by Graphics.SmoothingMode = SmoothingMode.AntiAlias is lost.
A possible solution is to avoid clipping the region defined by the GraphicsPath used to design the arcs (GraphicsPath.AddPie method); this, however, leaves the lines of the Pie visible, compromising the shape.
Another solution is to draw an ellipsis in the center of the arcs using the background color of the Canvas. Since the arcs are drawn using two rectangles, we can use the inner rectagle, inflate it (Rectangle.Inflate method) as needed (a fraction - Pen.Width / 2 - of the Pen size used for the ouline, usually).
This allows to delete the artifacts generated by the GraphicsPath shapes and to draw some other graphics content in the center of the shapes.
For example, using different Brushes:
LinearGradientBrush HatchBrush TextureBrush
Of course there are other methods to achieve the same result. We could draw the Arcs using the GraphicsPath.AddArc method, extract or calculate the first and last points of the Arcs and use them to draw two lines (GraphicsPath.AddLine) that will close the figures.
But, since we want to draw different graphics objects in the center of the arcs, these objects will cover the center area anyway.
How to use this code:
In a Form, add a TrackBar (named tbarSpeed, here)
Add a PictureBox (named Canvas), with Size (200, 200).
Wire up the TrackBar tbarSpeed_Scroll event and the Panel Canvas_Paint event.
using System.Drawing;
using System.Drawing.Drawing2D;
float GaugeValue = 88.0f;
float GaugeSweepAngle = 270.0f;
float GaugeStartAngle = 135.0F;
private void Canvas_Paint(object sender, PaintEventArgs e)
{
var canvas = sender as Control;
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
var outerRectangle = new Rectangle(10, 10, 180, 180);
var innerRectangle = new Rectangle(30, 30, 140, 140);
var blendRectangle = new Rectangle(10, 10, 180, 160);
var innerCenter = new PointF(outerRectangle.Left + (outerRectangle.Width / 2),
outerRectangle.Top + (outerRectangle.Height / 2));
float gaugeLength = (outerRectangle.Width / 2) - 2;
using (var path = new GraphicsPath())
{
path.AddPie(outerRectangle, GaugeStartAngle, GaugeSweepAngle);
path.AddPie(innerRectangle, GaugeStartAngle, GaugeSweepAngle);
innerRectangle.Inflate(-1, -1);
using (var pen = new Pen(Color.White, 3f))
using (var backgroundbrush = new SolidBrush(canvas.BackColor))
using (var gradientBrush = new LinearGradientBrush(blendRectangle,
Color.Green, Color.Red, LinearGradientMode.ForwardDiagonal))
{
var blend = new Blend()
{
Factors = new[] { 0.0f, 0.0f, 0.1f, 0.3f, 0.7f, 1.0f },
Positions = new[] { 0.0f, 0.2f, 0.4f, 0.6f, 0.8f, 1.0f }
};
gradientBrush.Blend = blend;
e.Graphics.FillPath(gradientBrush, path);
e.Graphics.DrawPath(pen, path);
e.Graphics.FillEllipse(backgroundbrush, innerRectangle);
using (var format = new StringFormat())
{
format.Alignment = StringAlignment.Center;
format.LineAlignment = StringAlignment.Center;
innerRectangle.Location = new Point(innerRectangle.X, innerRectangle.Y + canvas.Font.Height);
e.Graphics.DrawString(GaugeValue.ToString() + "%", canvas.Font, Brushes.White, innerRectangle, format);
}
using (var mx = new Matrix())
{
mx.RotateAt(GaugeStartAngle + 90 + (GaugeValue * (GaugeSweepAngle / 100)), innerCenter);
e.Graphics.Transform = mx;
e.Graphics.DrawLine(pen, innerCenter, new PointF(innerCenter.X, innerCenter.Y - gaugeLength));
e.Graphics.ResetTransform();
}
}
}
}
private void tbarSpeed_Scroll(object sender, EventArgs e)
{
GaugeValue = tbarSpeed.Value;
Canvas.Invalidate();
}
Sample code on PasteBin
How to draw a bezier with two colors? like the picture below?
I already have drawn the bezier, I can fill it with any color, however I cant the gradient working.
this is what im doing, im using a Path to create the bezier by the way.
private void test()
{
System.Windows.Media.GradientStop GradientStop1 = new System.Windows.Media.GradientStop();
System.Windows.Media.GradientStop GradientStop2 = new System.Windows.Media.GradientStop();
System.Windows.Media.LinearGradientBrush p_Fill; p_Fill = new System.Windows.Media.LinearGradientBrush(Colors.Blue, Colors.Red, new Point(0, 0.5), new Point(1, 0.5));
p_Fill.GradientStops.Add(GradientStop1);
p_Fill.GradientStops.Add(GradientStop2);
Bez.Fill = p_Fill;
}
This is how it should be
This is what I get
If you need a sharp cut between the 2 colored halves, you have to need more GradientStops:
var grad3 = new System.Windows.Media.GradientStop()
{Offset = 0.5, Color=Colors.Blue};
var grad4 = new System.Windows.Media.GradientStop()
{Offset = 0.5, Color=Colors.Red};
GradientStop2.Offset = 1;
p_Fill.GradientStops.Add(GradientStop1);
p_Fill.GradientStops.Add(grad3);
p_Fill.GradientStops.Add(grad4);
p_Fill.GradientStops.Add(GradientStop2);
Addtionally, you have to set the Brush for the Stroke, not the Fill. The StrokeThickness determines the thickness of the curve:
Bez.Stroke = p_Fill;
Bez.StrokeThickness = new Thickness(10);
I draw Polygon with this code:
Graphics surface;
surface = this.CreateGraphics();
SolidBrush brush = new SolidBrush(Color.Olive);
Point[] points = { new Point(50, 50), new Point(250, 50), new Point(50, 250) };
surface.FillPolygon(brush, points);
how to resize polygon Similar to the following?
Pic
Try this:
var g = e.Graphics;
var points=new PointF[] { new PointF(0, 0), new PointF(1, 0), new PointF(0, 1) };
var st=g.SaveState();
g.TranslateTransform(100f, 100f);
g.ScaleTransform(40f, 40f);
g.FillPolygon(Brushes.Olive, points);
g.Transform=mx;
g.TranslateTransform(300f, 100f);
g.ScaleTransform(80f, 80f);
g.FillPolygon(Brushes.MediumOrchid, points);
g.Restore(st);
which draws to polygons of the same shape on different locations with different sizes.
(red annotations added by me)
You have a couple options. A simple, rather silly solution would be to use linq:
double resizeValue = 1.5;
points.Select(x => new Point(x.X*resizeValue, x.Y*resizeValue);
That way is simple to understand, I think. May be better ways, but if this is all you're doing, it's probably sufficient.
Am using the below code to create polygon. i just want to fill this polygon surface with black dots, how i can do that, then i want to convert this polygon to bitmap or in memory stream, how to do this??
// Create a blue and a black Brush
SolidColorBrush yellowBrush = new SolidColorBrush();
yellowBrush.Color = Colors.Transparent;
SolidColorBrush blackBrush = new SolidColorBrush();
blackBrush.Color = Colors.Black;
// Create a Polygon
Polygon yellowPolygon = new Polygon();
yellowPolygon.Stroke = blackBrush;
yellowPolygon.Fill = yellowBrush;
yellowPolygon.StrokeThickness = 4;
// Create a collection of points for a polygon
System.Windows.Point Point1 = new System.Windows.Point(50, 100);
System.Windows.Point Point2 = new System.Windows.Point(200, 100);
System.Windows.Point Point3 = new System.Windows.Point(200, 200);
System.Windows.Point Point4 = new System.Windows.Point(300, 30);
PointCollection polygonPoints = new PointCollection();
polygonPoints.Add(Point1);
polygonPoints.Add(Point2);
polygonPoints.Add(Point3);
polygonPoints.Add(Point4);
// Set Polygon.Points properties
yellowPolygon.Points = polygonPoints;
// Add Polygon to the page
mygrid.Children.Add(yellowPolygon);
Do the dots have to be positioned in a particular order or do you just want to have a dotted pattern in your polygon without specific order?
If you don't need a special order you could use a Brush, a DrawingBrush for instance. Check out this link: http://msdn.microsoft.com/en-us/library/aa970904.aspx
You can then set this Brush as the Fill-Property of your Polygon instead of the SolidColorBrush.
This is the DrawingBrush example from the msdn link, but modified to display dots:
// Create a DrawingBrush and use it to
// paint the rectangle.
DrawingBrush myBrush = new DrawingBrush();
GeometryDrawing backgroundSquare =
new GeometryDrawing(
Brushes.Yellow,
null,
new RectangleGeometry(new Rect(0, 0, 100, 100)));
GeometryGroup aGeometryGroup = new GeometryGroup();
aGeometryGroup.Children.Add(new EllipseGeometry(new Rect(0, 0, 20, 20)));
SolidColorBrush checkerBrush = new SolidColorBrush(Colors.Black);
GeometryDrawing checkers = new GeometryDrawing(checkerBrush, null, aGeometryGroup);
DrawingGroup checkersDrawingGroup = new DrawingGroup();
checkersDrawingGroup.Children.Add(backgroundSquare);
checkersDrawingGroup.Children.Add(checkers);
myBrush.Drawing = checkersDrawingGroup;
myBrush.Viewport = new Rect(0, 0, 0.05, 0.05);
myBrush.TileMode = TileMode.Tile;
yellowPolygon.Fill = myBrush;