C# WinForm编写一个六边形菜单
作者：开发者精选资讯
这篇文章主要为大家详细介绍了如何利用C# WinForm编写一个六边形菜单,文中的示例代码讲解详细,具有一定的学习价值,有兴趣的可以参考下
背景
闲来无事逛群聊，看到一网友发来这么一个需求：
纯色图下面是一张六边形布局的背景图层，具体图片背景内容不便透露，所以这里采用色块形式模拟，ZF类的项目都喜欢这种给人新奇的东西，这每一个色块，都是一个可以点击进入的菜单。
分析
乍一看这图，就是三个正六边形嵌套。所以就根据公式 2 * Math.PI / 6计算出每个6边形每个顶点偏移角度，再根据公式计算出每个顶点的坐标位置。算法如下：
private static Point[] CalculateHexagonVertices(int sideLength, int offset = 0)
{
Point[] vertices = new Point[6];
double angle = 2 * Math.PI / 6;
for (int i = 0; i < 6; i++)
{
int x = offset + (int)(sideLength * Math.Cos(i * angle));
int y = offset + (int)(sideLength * Math.Sin(i * angle));
vertices[i] = new Point(x, y);
}
return vertices;
}首先根据 sideLength 边长，计算出最外层正六边形6个顶点的位置。注意这个时候因为顶点是从 (0,0) 计算的，所以这里要加入 offset 设置顶点位置，让每一顶点平移指定的像素。再计算中间那个小正六边形（包括蓝色间隙）的顶点位置。最后再计算最中间不包括间隙的紫色小正六边形顶点位置。这时候有人可能要问中间那些色块的位置怎么确定，这是个好问题，仔细看就知道了，这每一块都是一个等腰梯形，而且每个等腰梯形，都可以根据最外层的大正六边形和中间那个小正六边形（包括蓝色间隙）顶点位置计算出来。
实现
先定义一个梯形类：
internal sealed class Trapezoid
{
public Point TopLeft { get; set; }
public Point TopRight { get; set; }
public Point BottomLeft { get; set; }
public Point BottomRight { get; set; }
public Point[] Points
{
get
{
return new Point[] { TopLeft, TopRight, BottomRight, BottomLeft };
}
}
public Trapezoid(Point topLeft, Point topRight, Point bottomLeft, Point bottomRight)
{
TopLeft = topLeft;
TopRight = topRight;
BottomLeft = bottomLeft;
BottomRight = bottomRight;
}
}然后通过外层的两个正六边形顶点位置计算梯形位置，演示代码如下：
private static Trapezoid[] CalculateTrapezoids(Point[] hexagonVertices, Point[] smallHexagonVertices)
{
Trapezoid[] trapezoids = new Trapezoid[6];
for (int i = 0; i < 6; i++)
{
Point topLeft = hexagonVertices[i];
Point topRight = hexagonVertices[(i + 1) % 6];
Point bottomLeft = smallHexagonVertices[i];
Point bottomRight = smallHexagonVertices[(i + 1) % 6];
trapezoids[i] = new Trapezoid(topLeft, topRight, bottomLeft, bottomRight);
}
return trapezoids;
}我写了一个继承自 PictureBox 的控件类，重写了 OnPaint 方法，实现了以上色块的展示。演示代码如下：
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
var g = e.Graphics;
//centerHexagon 是中间最小的不包括间隙的紫色的六边形顶点位置
g.FillPolygon(new SolidBrush(Color.FromArgb(180, Color.Red)), centerHexagon);
for (int i = 0; i < trapezoids.Length; i++)
{
//trapezoids 是6个梯形位置
var trapezoid = trapezoids[i];
g.FillPolygon(new SolidBrush(Color.FromArgb(10 * (i + 1), Color.Yellow)), trapezoid.Points);
}
}需要实现鼠标点击事件，我们需要定义一个事件，记录鼠标当前位置，然后在 OnMouseClick 方法中检测鼠标位置是否在某个梯形或者最中间位置，然后触发事件。演示代码如下：
//0-6 每个梯形位置，-1 中间位置
// 4
// 3 5
// -1
// 2 0
// 1
/// <summary>
/// 菜单点击事件处理
/// </summary>
public event Action<object, int> OnMenuClicked;
/// <summary>
/// 鼠标当前位置
/// </summary>
private Point? mouseHoverLocation = null;
/// <summary>
/// 鼠标滑过的时候，重绘界面，然后设置鼠标位置
/// </summary>
/// <param name="e"></param>
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
mouseHoverLocation = e.Location;
Invalidate();
}
/// <summary>
/// 鼠标移除
/// </summary>
/// <param name="e"></param>
protected override void OnMouseLeave(EventArgs e)
{
base.OnMouseLeave(e);
mouseHoverLocation = null;
}
/// <summary>
/// 菜单点击事件
/// </summary>
/// <param name="e"></param>
protected override void OnMouseClick(MouseEventArgs e)
{
var mouseLocation = e.Location;
//检测鼠标是否在中间的六边形中：
if (IsPointInPolygon(mouseLocation, centerHexagon))
{
OnMenuClicked?.Invoke(this, -1);
return;
}
//检测是否在某个梯形内部
for (int i = 0; i < trapezoids.Length; i++)
{
var trapezoid = trapezoids[i];
if (IsPointInTrapezoid(mouseLocation, trapezoid))
{
OnMenuClicked?.Invoke(this, i);
return;
}
}
}里面有一个 IsPointInPolygon 方法，用于检测某一点是否在某个多边形内，这里的算法抄袭了某N上的代码，如下：
/// <summary>
/// 判断点是否在多边形内.
/// 来源：https://blog.csdn.net/xxdddail/article/details/49093635
/// ----------原理----------
/// 注意到如果从P作水平向左的射线的话，如果P在多边形内部，那么这条射线与多边形的交点必为奇数，
/// 如果P在多边形外部，则交点个数必为偶数(0也在内)。
/// </summary>
/// <param name="checkPoint">要判断的点</param>
/// <param name="polygonPoints">多边形的顶点</param>
/// <returns></returns>
private static bool IsPointInPolygon(Point checkPoint, Point[] polygonPoints)
{
bool inside = false;
int pointCount = polygonPoints.Length;
Point p1, p2;
for (int i = 0, j = pointCount - 1; i < pointCount; j = i, i++)//第一个点和最后一个点作为第一条线，之后是第一个点和第二个点作为第二条线，之后是第二个点与第三个点，第三个点与第四个点...
{
p1 = polygonPoints[i];
p2 = polygonPoints[j];
if (checkPoint.Y < p2.Y)
{//p2在射线之上
if (p1.Y <= checkPoint.Y)
{//p1正好在射线中或者射线下方
if ((checkPoint.Y - p1.Y) * (p2.X - p1.X) > (checkPoint.X - p1.X) * (p2.Y - p1.Y))//斜率判断,在P1和P2之间且在P1P2右侧
{
//射线与多边形交点为奇数时则在多边形之内，若为偶数个交点时则在多边形之外。
//由于inside初始值为false，即交点数为零。所以当有第一个交点时，则必为奇数，则在内部，此时为inside=(!inside)
//所以当有第二个交点时，则必为偶数，则在外部，此时为inside=(!inside)
inside = (!inside);
}
}
}
else if (checkPoint.Y < p1.Y)
{
//p2正好在射线中或者在射线下方，p1在射线上
if ((checkPoint.Y - p1.Y) * (p2.X - p1.X) < (checkPoint.X - p1.X) * (p2.Y - p1.Y))//斜率判断,在P1和P2之间且在P1P2右侧
{
inside = (!inside);
}
}
}
return inside;
}大致就是这样，再就是缩放窗体时自动计算位置的细节处理，这里先贴一下全部代码：
using System;
using System.Drawing;
using System.Windows.Forms;
namespace HexagonButton
{
public partial class HButton : PictureBox
{
//0-6 每个梯形位置，-1 中间位置
// 4
// 3 5
// -1
// 2 0
// 1
/// <summary>
/// 菜单点击事件处理
/// </summary>
public event Action<object, int> OnMenuClicked;
/// <summary>
/// 每个梯形位置
/// </summary>
private Trapezoid[] trapezoids = new Trapezoid[6];
/// <summary>
/// 中间的小正六边形位置
/// </summary>
private Point[] centerHexagon = new Point[6];
/// <summary>
/// 鼠标当前位置
/// </summary>
private Point? mouseHoverLocation = null;
/// <summary>
/// 鼠标滑过时的层背景
/// </summary>
private SolidBrush mouseHoverLayerBrush = new SolidBrush(Color.FromArgb(50, Color.White));
public HButton()
{
InitializeComponent();
DoubleBuffered = true;
}
/// <summary>
/// 缩放窗体时（调用），自动修正位置
/// </summary>
/// <param name="formWidth"></param>
/// <param name="formHeight"></param>
public void ResetSizeByForm(int formWidth, int formHeight)
{
var hHeight = (int)(formHeight * 0.8);
var hWidth = hHeight;
var hLeft = (formWidth - hWidth) / 2;
var hTop = (formHeight - hHeight) / 2;
this.Location = new Point(hLeft, hTop);
this.Width = hWidth;
this.Height = hHeight;
}
private void InitHexagonMenus()
{
this.BackColor = Color.Transparent;
//this.Image = Properties.Resources.button_bg;
this.SizeMode = PictureBoxSizeMode.Zoom;
this.Cursor = Cursors.Hand;
//计算图片缩放级别
//var scale = Properties.Resources.button_bg.Width / this.Width;
//计算原始图片高度和宽度之差，因为该背景非正六边形，所以计算一下宽度和高度之差，用以计算正确得位置
//var diffOfImageSize = (Properties.Resources.button_bg.Width - Properties.Resources.button_bg.Height) / scale;
var diffOfImageSize = 0;
var sideWidth = (this.Width - diffOfImageSize) / 2;
var offset = this.Width / 2;
//计算最外层大六边形顶点位置
var big = CalculateHexagonVertices((this.Width + diffOfImageSize / 2) / 2, offset);
//计算内部小六边形顶点位置
var small = CalculateHexagonVertices(sideWidth / 2, offset);
//计算两个六边形相交之后，形成得六边形环，分割为6个等腰梯形，用以检测点击事件
trapezoids = CalculateTrapezoids(big, small);
//计算内部小的正六边形，用以检测点击事件
centerHexagon = CalculateHexagonVertices(sideWidth / 2 - 20, offset);
}
/// <summary>
/// 鼠标滑过的时候，重绘界面，然后设置鼠标位置
/// </summary>
/// <param name="e"></param>
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
mouseHoverLocation = e.Location;
Invalidate();
}
/// <summary>
/// 鼠标移除
/// </summary>
/// <param name="e"></param>
protected override void OnMouseLeave(EventArgs e)
{
base.OnMouseLeave(e);
mouseHoverLocation = null;
}
/// <summary>
/// 菜单点击事件
/// </summary>
/// <param name="e"></param>
protected override void OnMouseClick(MouseEventArgs e)
{
var mouseLocation = e.Location;
//检测鼠标是否在中间的六边形中：
if (IsPointInPolygon(mouseLocation, centerHexagon))
{
OnMenuClicked?.Invoke(this, -1);
return;
}
//检测是否在某个梯形内部
for (int i = 0; i < trapezoids.Length; i++)
{
var trapezoid = trapezoids[i];
if (IsPointInTrapezoid(mouseLocation, trapezoid))
{
OnMenuClicked?.Invoke(this, i);
return;
}
}
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
var g = e.Graphics;
#if DEBUG
//以下的代码可以直接删除，这里是作为标识多边形位置
g.FillPolygon(new SolidBrush(Color.FromArgb(180, Color.Red)), centerHexagon);
for (int i = 0; i < trapezoids.Length; i++)
{
var trapezoid = trapezoids[i];
g.FillPolygon(new SolidBrush(Color.FromArgb(10 * (i + 1), Color.Yellow)), trapezoid.Points);
}
#endif
if (mouseHoverLocation == null)
{
return;
}
//检测鼠标是否在中间的六边形中：
if (IsPointInPolygon(mouseHoverLocation.Value, centerHexagon))
{
g.FillPolygon(mouseHoverLayerBrush, centerHexagon);
return;
}
//检测是否在某个梯形内部
for (int i = 0; i < trapezoids.Length; i++)
{
var trapezoid = trapezoids[i];
if (IsPointInTrapezoid(mouseHoverLocation.Value, trapezoid))
{
g.FillPolygon(mouseHoverLayerBrush, trapezoid.Points);
return;
}
}
}
/// <summary>
/// 计算正六边形的顶点坐标
/// </summary>
/// <param name="sideLength"></param>
/// <param name="offset"></param>
/// <returns></returns>
private static Point[] CalculateHexagonVertices(int sideLength, int offset = 0)
{
Point[] vertices = new Point[6];
double angle = 2 * Math.PI / 6;
for (int i = 0; i < 6; i++)
{
int x = offset + (int)(sideLength * Math.Cos(i * angle));
int y = offset + (int)(sideLength * Math.Sin(i * angle));
vertices[i] = new Point(x, y);
}
return vertices;
}
/// <summary>
/// 计算每个梯形的坐标
/// </summary>
/// <param name="hexagonVertices"></param>
/// <param name="smallHexagonVertices"></param>
/// <returns></returns>
private static Trapezoid[] CalculateTrapezoids(Point[] hexagonVertices, Point[] smallHexagonVertices)
{
Trapezoid[] trapezoids = new Trapezoid[6];
for (int i = 0; i < 6; i++)
{
Point topLeft = hexagonVertices[i];
Point topRight = hexagonVertices[(i + 1) % 6];
Point bottomLeft = smallHexagonVertices[i];
Point bottomRight = smallHexagonVertices[(i + 1) % 6];
trapezoids[i] = new Trapezoid(topLeft, topRight, bottomLeft, bottomRight)
{
Index = i
};
}
return trapezoids;
}
/// <summary>
/// 判断点是否在梯形内
/// </summary>
/// <param name="checkPoint"></param>
/// <param name="trapezoid"></param>
/// <returns></returns>
private static bool IsPointInTrapezoid(Point checkPoint, Trapezoid trapezoid)
{
return IsPointInPolygon(checkPoint, trapezoid.Points);
}
/// <summary>
/// 判断点是否在多边形内.
/// 来源：https://blog.csdn.net/xxdddail/article/details/49093635
/// ----------原理----------
/// 注意到如果从P作水平向左的射线的话，如果P在多边形内部，那么这条射线与多边形的交点必为奇数，
/// 如果P在多边形外部，则交点个数必为偶数(0也在内)。
/// </summary>
/// <param name="checkPoint">要判断的点</param>
/// <param name="polygonPoints">多边形的顶点</param>
/// <returns></returns>
private static bool IsPointInPolygon(Point checkPoint, Point[] polygonPoints)
{
bool inside = false;
int pointCount = polygonPoints.Length;
Point p1, p2;
for (int i = 0, j = pointCount - 1; i < pointCount; j = i, i++)//第一个点和最后一个点作为第一条线，之后是第一个点和第二个点作为第二条线，之后是第二个点与第三个点，第三个点与第四个点...
{
p1 = polygonPoints[i];
p2 = polygonPoints[j];
if (checkPoint.Y < p2.Y)
{//p2在射线之上
if (p1.Y <= checkPoint.Y)
{//p1正好在射线中或者射线下方
if ((checkPoint.Y - p1.Y) * (p2.X - p1.X) > (checkPoint.X - p1.X) * (p2.Y - p1.Y))//斜率判断,在P1和P2之间且在P1P2右侧
{
//射线与多边形交点为奇数时则在多边形之内，若为偶数个交点时则在多边形之外。
//由于inside初始值为false，即交点数为零。所以当有第一个交点时，则必为奇数，则在内部，此时为inside=(!inside)
//所以当有第二个交点时，则必为偶数，则在外部，此时为inside=(!inside)
inside = (!inside);
}
}
}
else if (checkPoint.Y < p1.Y)
{
//p2正好在射线中或者在射线下方，p1在射线上
if ((checkPoint.Y - p1.Y) * (p2.X - p1.X) < (checkPoint.X - p1.X) * (p2.Y - p1.Y))//斜率判断,在P1和P2之间且在P1P2右侧
{
inside = (!inside);
}
}
}
return inside;
}
/// <summary>
/// 当窗体改变时，自动计算大小
/// </summary>
/// <param name="e"></param>
protected override void OnClientSizeChanged(EventArgs e)
{
base.OnClientSizeChanged(e);
InitHexagonMenus();
}
}
/// <summary>
/// 梯形类
/// </summary>
internal sealed class Trapezoid
{
public int Index { get; set; }
public Point TopLeft { get; set; }
public Point TopRight { get; set; }
public Point BottomLeft { get; set; }
public Point BottomRight { get; set; }
public Point[] Points
{
get
{
return new Point[] { TopLeft, TopRight, BottomRight, BottomLeft };
}
}
public Trapezoid(Point topLeft, Point topRight, Point bottomLeft, Point bottomRight)
{
TopLeft = topLeft;
TopRight = topRight;
BottomLeft = bottomLeft;
BottomRight = bottomRight;
}
public override string ToString()
{
return $"Trapezoid {{ Index={Index}, TopLeft={TopLeft}, TopRight={TopRight}, BottomLeft={BottomLeft}, BottomRight={BottomRight} }}";
}
}
}窗体代码：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace HexagonButton
{
public partial class Form1 : Form
{
private HButton HButton;
public Form1()
{
InitializeComponent();
this.WindowState = FormWindowState.Maximized;
//这个窗体里面把那个纯色的背景图放进去
this.BackColor = Color.FromArgb(9, 56, 128);
}
protected override void OnSizeChanged(EventArgs e)
{
base.OnSizeChanged(e);
if (HButton == null)
{
HButton = new HButton();
HButton.OnMenuClicked += (s, index) =>
{
MessageBox.Show($"点击了菜单：#{index}");
};
this.Controls.Add(HButton);
}
else
{
HButton.ResetSizeByForm(this.Width, this.Height);
}
}
}
}就是在窗体缩放时，把六边形菜单动态加进去。
结局
代码发给网友之后，网友表示很满意，然后经过我的指导，然后自由发挥改成了7边形，然后我又扩展了下面这一版，更加智能了。截一些图片在这里：
最终版演示 DEMO：
做着做着，就一发不可收拾了，做的越来越顺眼了... 最后，该菜单通过增加了一些配置，使得可以自定义边数，是否包含中间菜单等功能，功能更加强大了一些。该项目已全部开源，开源地址：https://github.com/mrhuo/polymenuNUGET 安装：
Install-Package MrHuo.PolyMenu -Version 1.0.23.913
以上就是C# WinForm编写一个六边形菜单的详细内容，更多关于C# WinForm菜单的资料请关注脚本之家其它相关文章！