A*寻路算法基于C#实现
玩过即时战略，RPG等类型的游戏的朋友一定会知道，当我们用鼠标选取某些单位并命令其到达地图上确定的位置时，这些单位总是可以自动的选择最短的路径到达。这个时候我们就会联想到大名鼎鼎的A*寻路算法，下文简略介绍算法实现原理，并附上C#实现方法。
算法原理请见：http://data.gameres.com/message.asp?TopicID=25439
代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
namespace ConsoleApplication2
{
class Program
{
static void Main(string[] args)
{
test mytest = new test();
//定义出发位置
Point pa = new Point();
pa.x = 1;
pa.y = 1;
//定义目的地
Point pb = new Point();
pb.x = 8;
pb.y = 8;
mytest.FindWay(pa, pb);
mytest.PrintMap();
Console.ReadLine();
}
}
class test
{
//数组用1表示可通过，0表示障碍物
byte[,] R = new byte[10, 10] {
{ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 },
{ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 },
{ 1, 1, 1, 1, 0, 1, 1, 1, 1, 1 },
{ 1, 1, 1, 1, 0, 1, 1, 1, 1, 1 },
{ 1, 1, 1, 1, 0, 1, 1, 1, 1, 1 },
{ 1, 1, 1, 1, 0, 1, 1, 1, 1, 1 },
{ 1, 1, 1, 1, 0, 1, 1, 1, 1, 1 },
{ 1, 1, 1, 1, 0, 1, 1, 1, 1, 1 },
{ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 },
{ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }
};
//开启列表
List<Point> Open_List = new List<Point>();
//关闭列表
List<Point> Close_List = new List<Point>();
//从开启列表查找F值最小的节点
private Point GetMinFFromOpenList()
{
Point Pmin = null;
foreach (Point p in Open_List) if (Pmin==null || Pmin.G + Pmin.H > p.G + p.H) Pmin = p;
return Pmin;
}
//判断一个点是否为障碍物
private bool IsBar(Point p, byte[,] map)
{
if (map[p.y, p.x] == 0) return true;
return false;
}
//判断关闭列表是否包含一个坐标的点
private bool IsInCloseList(int x, int y)
{
foreach (Point p in Close_List) if (p.x == x && p.y == y) return true;
return false;
}
//从关闭列表返回对应坐标的点
private Point GetPointFromCloseList(int x, int y)
{
foreach (Point p in Close_List) if (p.x == x && p.y == y) return p;
return null;
}
//判断开启列表是否包含一个坐标的点
private bool IsInOpenList(int x, int y)
{
foreach (Point p in Open_List) if (p.x == x && p.y == y) return true;
return false;
}
//从开启列表返回对应坐标的点
private Point GetPointFromOpenList(int x, int y)
{
foreach (Point p in Open_List) if (p.x == x && p.y == y) return p;
return null;
}
//计算某个点的G值
private int GetG(Point p)
{
if (p.father == null) return 0;
if (p.x == p.father.x || p.y == p.father.y) return p.father.G + 10;
else return p.father.G + 14;
}
//计算某个点的H值
private int GetH(Point p, Point pb)
{
return Math.Abs(p.x - pb.x) + Math.Abs(p.y - pb.y);
}
//检查当前节点附近的节点
private void CheckP8(Point p0, byte[,] map, Point pa, ref Point pb)
{
for (int xt = p0.x - 1; xt <= p0.x + 1; xt++)
{
for (int yt = p0.y - 1; yt <= p0.y + 1; yt++)
{
//排除超过边界和等于自身的点
if ((xt >= 0 && xt < 10 && yt >= 0 && yt < 10) && !(xt == p0.x && yt == p0.y))
{
//排除障碍点和关闭列表中的点
if (map[yt, xt] != 0 && !IsInCloseList(xt, yt))
{
if (IsInOpenList(xt, yt))
{
Point pt = GetPointFromOpenList(xt, yt);
int G_new = 0;
if (p0.x == pt.x || p0.y == pt.y) G_new = p0.G + 10;
else G_new = p0.G + 14;
if (G_new < pt.G)
{
Open_List.Remove(pt);
pt.father = p0;
pt.G = G_new;
Open_List.Add(pt);
}
}
else
{
//不在开启列表中
Point pt = new Point();
pt.x = xt;
pt.y = yt;
pt.father = p0;
pt.G = GetG(pt);
pt.H = GetH(pt, pb);
Open_List.Add(pt);
}
}
}
}
}
}
public void FindWay(Point pa, Point pb)
{
Open_List.Add(pa);
while (!(IsInOpenList(pb.x, pb.y) || Open_List.Count == 0))
{
Point p0 = GetMinFFromOpenList();
if (p0 == null) return;
Open_List.Remove(p0);
Close_List.Add(p0);
CheckP8(p0, R, pa, ref pb);
}
Point p = GetPointFromOpenList(pb.x, pb.y);
while (p.father != null)
{
p = p.father;
R[p.y, p.x] = 3;
}
}
public void SaveWay( Point pb)
{
Point p = pb;
while (p.father != null)
{
p = p.father;
R[p.y, p.x] = 3;
}
}
public void PrintMap()
{
for (int a = 0; a < 10; a++)
{
for (int b = 0; b < 10; b++)
{
if (R[a, b] == 1) Console.Write("█");
else if (R[a, b] == 3) Console.Write("★");
else if (R[a, b] == 4) Console.Write("○");
else Console.Write(" ");
}
Console.Write("\n");
}
}
}
class Point
{
public int y;
public int x;
public int G;
public int H;
public Point()
{
}
public Point(int x0, int y0, int G0, int H0, Point F)
{
x = x0;
y = y0;
G = G0;
H = H0;
father = F;
}
public Point father;
}
}
