List<T>的搜索和排序

原来是通过委托来实现的啊0 0...

Code:

public class Vector

{
public double? R = null;

public double? Theta = null;


public double? ThetaRadians

{
get
{
return (Theta * Math.PI / 180.0);

}
}

public Vector(double? r, double? theta)

{

if (r > 0)

{
r = -r;
theta += 180;
}
theta = theta % 360;

R = r;
Theta = theta;
}

/// <summary>

/// 重载+运算符

/// </summary>

/// <param name="op1"></param>

/// <param name="op2"></param>

/// <returns></returns>

public static Vector operator +(Vector op1, Vector op2)

{
try
{
double newX = op1.R.Value * Math.Sin(op1.ThetaRadians.Value) + op2.R.Value * Math.Sin(op2.ThetaRadians.Value);

double newY = op1.R.Value * Math.Cos(op1.ThetaRadians.Value) + op2.R.Value * Math.Cos(op2.ThetaRadians.Value);


double newR = Math.Sqrt(newX * newX + newY * newY);

double newTheta = Math.Atan2(newX, newY) * 180.0 / Math.PI;


return new Vector(newR, newTheta);

}
catch
{
return new Vector(null, null);

}
}

/// <summary>

/// 重载-运算符

/// </summary>

/// <param name="op1"></param>

/// <returns></returns>

public static Vector operator -(Vector op1)

{
return new Vector(-op1.R, op1.Theta);

}

/// <summary>

/// 重载-运算符

/// </summary>

/// <param name="op1"></param>

/// <param name="op2"></param>

/// <returns></returns>

public static Vector operator -(Vector op1, Vector op2)

{
return op1 + (-op2);

}

/// <summary>

/// 重写ToString()运算符

/// </summary>

/// <returns></returns>

public override string ToString()

{
string rString = R.HasValue ? R.ToString() : "null";

string thetaString = Theta.HasValue ? Theta.ToString() : "null";


return string.Format("({0},{1})", rString, thetaString);

}

}

class Vectors:List<Vector>

{
public Vectors()

{
}

public Vectors(IEnumerable<Vector> initiaItems)

{
foreach (Vector vector in initiaItems)

{
Add(vector);
}

}

public string Sum()

{
StringBuilder sb = new StringBuilder();

Vector currenPoint = new Vector(0.0, 0.0);

sb.Append("origin");

foreach (Vector vector in this)

{
sb.AppendFormat(" + {0}", vector);

currenPoint += vector;
}

sb.AppendFormat(" = {0}", currenPoint);

return sb.ToString();

}
}

public static class VectorDelegates

{
//排序方法
public static int Compare(Vector x,Vector y)

{
if (x.R > y.R)

{
return 1;

}
else if (x.R < y.R)

{
return -1;

}
else

{
return 0;

}
}
//搜索方法
public static bool TopRightQuadrant(Vector target)

{
if (target.Theta >= 0.0 && target.Theta <= 90.0)

{
return true;

}
else

{
return false;

}
}
}

class Program
{
static void Main(string[] args)

{
Vectors route = new Vectors();

route.Add(new Vector(2.0, 90.0));

route.Add(new Vector(1.0, 180.0));

route.Add(new Vector(0.5, 45.0));

route.Add(new Vector(2.5, 315.0));


Console.WriteLine(route.Sum());

//排序委托
Comparison<Vector> sorter = new Comparison<Vector>(VectorDelegates.Compare);

//排序
route.Sort(sorter);

Console.WriteLine(route.Sum());

//搜索委托

Predicate<Vector> searcher = new Predicate<Vector>(VectorDelegates.TopRightQuadrant);

//搜索

Vectors topRightQuadrantRoute = new Vectors(route.FindAll(searcher));


Console.WriteLine(topRightQuadrantRoute.Sum());
Console.ReadKey();
}
}