复制构造函数转到基础构造函数并覆盖复制的值答案

【问题标题】：Copy Constructor going to base constructor and overwriting copied values复制构造函数转到基础构造函数并覆盖复制的值
【发布时间】：2012-01-02 04:42:13
【问题描述】：

构造函数难题，我有这两个构造函数。一个是用于制作类的副本，另一个是标准构造函数。我需要调用第一个，以便我可以使用其中的规则。我不应该重复代码，所以我正在寻找一种方法来避免覆盖两个维度。

public SprinklerLineModel()
    {

        NearCrossMainDimension = new PipeDimensionModel();
        FarCrossMainDimension = new PipeDimensionModel();

        this.AddValidationRule(Rule.CreateRule(() => BranchLineDiameter, RuleMessage.GREATER_THAN_ZERO, () => BranchLineDiameter > 0));
    }

    /// <summary>
    /// Copy Constructor
    /// </summary>
    /// <param name="sprinklerLineModel">Original copy of sprinklerLineModel</param>
    public SprinklerLineModel(SprinklerLineModel sprinklerLineModel)
        :this()
    {
        this.EstimatedFlow = sprinklerLineModel.EstimatedFlow;
        this.EstimatedPressure = sprinklerLineModel.EstimatedPressure;
        this.NearCrossMainDimension = new PipeDimensionModel(sprinklerLineModel.NearCrossMainDimension);
        this.FarCrossMainDimension = new PipeDimensionModel(sprinklerLineModel.FarCrossMainDimension);
        this.BranchLineDiameter = sprinklerLineModel.BranchLineDiameter;
        this.LeadLinePipeFittingLength = sprinklerLineModel.LeadLinePipeFittingLength;
        this.ExbPipeFittingLength = sprinklerLineModel.ExbPipeFittingLength;

        this.IsDirty = sprinklerLineModel.IsDirty;
    }

我希望能够在不覆盖两个变量的情况下调用默认构造函数。任何帮助，将不胜感激。

我想我可以检查一下它们是否为空，但这似乎不是最好的方法。

谢谢

【问题讨论】：

标签： c# constructor overloading copy-constructor default-constructor

【解决方案1】：

我会提取一个初始化方法并从两个构造函数中调用该方法。

public SprinklerLineModel()
{
    NearCrossMainDimension = new PipeDimensionModel();
    FarCrossMainDimension = new PipeDimensionModel();
    Init();
}

public SprinklerLineModel(SprinklerLineModel sprinklerLineModel)
{
    this.EstimatedFlow = sprinklerLineModel.EstimatedFlow;
    this.EstimatedPressure = sprinklerLineModel.EstimatedPressure;
    this.NearCrossMainDimension = new PipeDimensionModel(sprinklerLineModel.NearCrossMainDimension);
    this.FarCrossMainDimension = new PipeDimensionModel(sprinklerLineModel.FarCrossMainDimension);
    this.BranchLineDiameter = sprinklerLineModel.BranchLineDiameter;
    this.LeadLinePipeFittingLength = sprinklerLineModel.LeadLinePipeFittingLength;
    this.ExbPipeFittingLength = sprinklerLineModel.ExbPipeFittingLength;
    this.IsDirty = sprinklerLineModel.IsDirty;
    Init();
}

void Init()
{
    this.AddValidationRule(Rule.CreateRule(() => BranchLineDiameter, RuleMessage.GREATER_THAN_ZERO, () => BranchLineDiameter > 0));
}

【讨论】：

【解决方案2】：

我会这样做：

public SprinklerLineModel()
    : this(null)
{
}

/// <summary> 
/// Copy Constructor 
/// </summary> 
/// <param name="sprinklerLineModel">Original copy of sprinklerLineModel</param> 
public SprinklerLineModel(SprinklerLineModel sprinklerLineModel)
{
    this.EstimatedFlow = sprinklerLineModel.EstimatedFlow;
    this.EstimatedPressure = sprinklerLineModel.EstimatedPressure;
    if (sprinklerLineModel != null)
    {
        this.NearCrossMainDimension = new PipeDimensionModel(sprinklerLineModel.NearCrossMainDimension);
        this.FarCrossMainDimension = new PipeDimensionModel(sprinklerLineModel.FarCrossMainDimension);
    }
    else
    {
        NearCrossMainDimension = new PipeDimensionModel();
        FarCrossMainDimension = new PipeDimensionModel();
    }
    this.BranchLineDiameter = sprinklerLineModel.BranchLineDiameter;
    this.LeadLinePipeFittingLength = sprinklerLineModel.LeadLinePipeFittingLength;
    this.ExbPipeFittingLength = sprinklerLineModel.ExbPipeFittingLength;

    this.IsDirty = sprinklerLineModel.IsDirty;

    this.AddValidationRule(Rule.CreateRule(() => BranchLineDiameter, RuleMessage.GREATER_THAN_ZERO, () => BranchLineDiameter > 0));
}

优点是您可以在一个地方实现。

/蒂比

【讨论】：