public static void Main(string[] args)
{
    Boss boss = new Boss();
    boss.SetBuilder(new CommonBuilder());   //同样的构建过程不同的表示
    boss.Delivery();    //出货，一般电脑

    boss.SetBuilder(new SeniorBuilder());
    boss.Delivery();    //出货，高端电脑
}

/// <summary>
/// 建造者模式中的指挥者
/// </summary>
public class Boss
{
    public Builder builder { get; set; }
    public void SetBuilder(Builder builder)
    {
        this.builder = builder;
    }

    /// <summary>
    /// 提货
    /// </summary>
    public void Delivery()
    {
        Console.WriteLine(builder.GetComputer().ToString());
    }
}

/// <summary>
/// 抽象建造者 
/// </summary>
public abstract class Builder
{
    public abstract string BuildCPU();
    public abstract string BuildMemory();
    public abstract string BuildHD();

    /// <summary>
    /// 构建过程一般是固定的，当然也可以在子类override
    /// </summary>
    /// <returns></returns>
    public virtual Computer GetComputer()
    {
        return new Computer
        {
            CPU = BuildCPU(),
            Memory = BuildMemory(),
            HD = BuildHD()
        };
    }
}
    
/// <summary>
/// 具体建造者 一般电脑
/// </summary>
public class CommonBuilder : Builder
{
    public override string BuildCPU()
    {
        return "Intel 5";
    }

    public override string BuildHD()
    {
        return "希捷 5400转 500G";
    }

    public override string BuildMemory()
    {
        return "金士顿 ddr3 4G";
    }

    public override Computer GetComputer()
    {
        return new Computer
        {
            CPU = BuildCPU(),
            Memory = BuildMemory(),
            HD = BuildHD()
        };
    }
}

/// <summary>
/// 具体建造者 高端电脑
/// </summary>
public class SeniorBuilder : Builder
{
    public override string BuildCPU()
    {
        return "Intel 7";
    }

    public override string BuildHD()
    {
        return "SSD 1T";
    }

    public override string BuildMemory()
    {
        return "金士顿 ddr4 16G";
    }

    public override Computer GetComputer()
    {
        return new Computer
        {
            CPU = BuildCPU(),
            Memory = BuildMemory(),
            HD = BuildHD()
        };
    }
}

/// <summary>
/// 构建的产品
/// </summary>
public class Computer
{
    public string CPU { get; set; }
    public string Memory { get; set; }
    public string HD { get; set; }

    public override string ToString()
    {
        var newLine = System.Environment.NewLine;
        return $"CPU:{CPU}{newLine}内存:{Memory}{newLine}硬盘:{HD}{newLine}";
    }
}