OOP创建和复制依赖于一个值的对象

Question

I am sorry but I didn't know what to call this post (if you have a better title please tell me in a comment).

Say for instance you have the following Object whose purpose is to create chart series of the data specified in the Constructor :

/**
 * Helper to generate chart series 
 */
public class ChartHelper
{
    public System.Windows.Forms.DataVisualization.Charting.Chart ChartType { get; set; }
    public String TimeType { get; set; }
    private readonly List<IObject> _datalist;
    private readonly TimeType _timeType;
    private readonly DateTime _stopDate;
    private readonly DateTime _startDate;

    public ChartHelper(List<IObject> dataList, TimeType timeType, DateTime startDate, DateTime stopDate)
    {
        _startDate = startDate;
         _stopDate = stopDate;
        _datalist = dataList;
        _timeType = timeType;
    }


    public System.Windows.Forms.DataVisualization.Charting.Chart GetChart()
    {
        CreateSeries(_startDate);
        return ChartType;
    }

    private void CreateSeries(DateTime seriesTime)
    {
      //Do something
    }

   //More internal private methods

}

Now say for instance you have a program that creates 10 different Charts but only the value of the List<IObject> dataList changes.

Then you could do one of two things:

1. Create 10 different ChartHelper Objects
2. Use the same Object and change the dataList value

This is of course an example of how the problem could be presented when developing (ive met this problem several times)

My question is, is there a design pattern that helps you solve this issue ? Or is there a best practice method that would be useful for these situations? It is important for me to learn these methods as I wish to improve my own skills.

Answer 1

If only the data is different then I would recommend using the same class and creating 10 different objects from it.

If however the implementation of the CreateSeries would be different depending on the type of data, than this would be a candidate for the Strategy pattern. In that case you would extract the creation of the series behind an interface and provide implementations for the different kinds of series. You could then also have a factory that picks the correct strategy depending on the data and composes a chart (helper).