问题描述
实际上，在单击每个圆圈之后，我希望更改其颜色，例如，我希望将其变为红色，总体而言，我想将其视为控件.
Actually, after clicking on each circle i want its color to be changed, for instance, i want it to turn into red,Overall, i wanna treat it as control.
当我双击图片框时，我知道如何绘制代表图形节点的圆.我正在使用以下代码:
i know how to draw the circles that represent the nodes of the graph when i Double click on the picturebox. i'm using the following code:
public Form1()
{
InitializeComponent();
pictureBox1.Paint += new PaintEventHandler(pic_Paint);
}
public Point positionCursor { get; set; }
private List<Point> points = new List<Point>();
public int circleNumber { get; set; }
private void pictureBox1_DoubleClick(object sender, EventArgs e)
{
positionCursor = this.PointToClient(new Point(Cursor.Position.X - 25, Cursor.Position.Y - 25));
points.Add(positionCursor);
Label lbl = new Label();
lbl.BackColor = Color.Transparent;
lbl.Font = new Font("Arial", 7);
lbl.Size = new Size(20, 15);
if (circleNumber >= 10)
{
lbl.Location = new Point(points[circleNumber].X + 3, points[circleNumber].Y + 6);
}
else
{
lbl.Location = new Point(points[circleNumber].X + 7, points[circleNumber].Y + 7);
}
lbl.Text = circleNumber.ToString();
pictureBox1.Controls.Add(lbl);
circleNumber++;
pictureBox1.Invalidate();
}
private void pic_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
g.SmoothingMode = SmoothingMode.AntiAlias;
using (var pen = new Pen(Color.DimGray, 2))
{
foreach (Point pt in points)
{
g.FillEllipse(Brushes.White, pt.X, pt.Y, 25, 25);
g.DrawEllipse(pen, pt.X, pt.Y, 26, 26);
}
}
}
推荐答案
您需要执行点击测试以检查点是否在圆上.作为一种选择，您可以在 GraphicsPath 并使用 IsVisible 方法，用于检查该点是否为圆形.
You need to perform a hit-test to check if a point is in a circle. As an option you can add a circle to a GraphicsPath and the use IsVisible method of the path to check if the point is in circle.
例如，将柔和的p作为直径为d的圆的左上角位置，您可以检查当前单击的点是否在圆中或以这种方式位于圆锥中:
For example having a ponit p as top-left location of a circle with diameter d, you can check if current clicked point is in the circle or con this way:
var result = false;
using (var path = new GraphicsPath())
{
path.AddEllipse(p.X, p.Y, d, d);
result = path.IsVisible(e.Location);
}
示例代码
我看到您在本主题中问了多个问题.因此，在这里我分享一些代码来帮助您朝正确的方向前进.
I see you have asked multiple questions in this topic. So here I share some code to help you to be in right direction.
为填充颜色，选定的填充颜色，圆形大小，边框宽度等定义变量，以便可以根据需要轻松更改它们.
define variables for fill color, selected fill color, circle size, border width and etc, to be able to change them simply if you need.
List<Rectangle> Shapes = new List<Rectangle>();
int selectedIndex = -1;
Size size = new Size(25, 25);
Color fillColor = Color.White;
Color selectedfillCOlor = Color.Red;
Color borderColor = Color.Gray;
int borderWidth = 2;
DoubleClick
在此处将圆添加到Shapes列表.将圆形的边界矩形添加到列表中就足够了.
Here add circles to the Shapes list. It's enough to add the bounding rectangle of a circle to the list.
private void pic_MouseDoubleClick(object sender, MouseEventArgs e)
{
var p = e.Location;
p.Offset(-size.Width / 2, -size.Height / 2);
Shapes.Add(new Rectangle(p, size));
pic.Invalidate();
}
点击
在这里执行点击测试以检查该点是否在一个圆圈中.单击时检查键是否向下，以进行选择，然后将找到的索引设置为selectedIndex绘画时使用它.
Here perform hit-test to check if the point is in one of circles.Check if the key is down when click, to make selection, then set the found index as selectedIndex to use it when painting.
private void pic_MouseClick(object sender, MouseEventArgs e)
{
if (ModifierKeys != Keys.Control)
return;
selectedIndex = -1;
for (int i = 0; i < Shapes.Count; i++)
{
using (var path = new GraphicsPath())
{
path.AddEllipse(Shapes[i]);
if (path.IsVisible(e.Location))
selectedIndex = i;
}
}
pic.Invalidate();
}
绘画
将图形对象的SmoothingMode设置为AntiAlias可使图形更平滑.然后在for循环中绘制形状，并注意selectedIndex为选定的形状使用其他填充颜色.
Set SmoothingMode of graphics object to AntiAlias to have a more smooth drawing. Then draw shapes in a for loop and pay attention to selectedIndex to use a different fill color for selected shape.
要绘制文本，不需要使用label，您只需使用TextRenderer类绘制文本即可.
To draw the text, yo don't need to use a label and you can simply draw text using TextRenderer class.
private void pic_Paint(object sender, PaintEventArgs e)
{
e.Graphics.SmoothingMode = SmoothingMode.AntiAlias;
for (int i = 0; i < Shapes.Count; i++)
{
var selected = (selectedIndex == i);
using (var brush = new SolidBrush(selected ? selectedfillCOlor : fillColor))
e.Graphics.FillEllipse(brush, Shapes[i]);
using (var pen = new Pen(borderColor, borderWidth))
e.Graphics.DrawEllipse(pen, Shapes[i]);
TextRenderer.DrawText(e.Graphics, (i + 1).ToString(),
this.Font, Shapes[i], Color.Black,
TextFormatFlags.VerticalCenter | TextFormatFlags.HorizontalCenter);
}
}
一些注释
-
最好将代码封装在从
PictureBox或派生的Control派生的新控件中，并将DoubleBuffered设置为true.
It's better to encapsulate codes in a new control derived from
PictureBoxor derivedControland setDoubleBufferedto true.
将Circle封装在Circle类中是一个不错的选择，该类执行命中测试和圆的渲染.特别是如果您想稍后移动它们或执行其他一些交互操作，或者让每个圆圈都有其自己的属性，例如color等.
It's a good option to encapsulate Circle in a Circle class which performs hit testing and rendering of a circle. Specially if you want to move them later or perform some other interactions or let each circle has it's own properties like color ,etc.
示例圈子课程
这里有一个示例圈子课程，可以作为一个很好的起点.
Here is a sample circle class which can be a good start point.
public class Circle
{
private Color selectedFillColor = Color.Red;
private Color normalFillColor = Color.Red;
private Color borderColor = Color.Red;
private int borderWidth = 2;
public Point Location { get; set; }
public int Diameter { get; set; }
public Rectangle Bounds
{
get
{
return new Rectangle(Location, new Size(Diameter, Diameter));
}
}
public bool HitTest(Point p)
{
var result = false;
using (var path = new GraphicsPath())
{
path.AddEllipse(Bounds);
result = path.IsVisible(p);
}
return result;
}
public bool Selected { get; set; }
public void Draw(Graphics g)
{
using (var brush = new SolidBrush(
Selected ? selectedFillColor : normalFillColor))
g.FillEllipse(brush, Bounds);
using (var pen = new Pen(borderColor, 2))
g.DrawEllipse(pen, Bounds);
}
}
这篇关于绘制圆后如何将其作为控件? -移动和选择形状的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！