Framework Design(1) : 建構子應該只傳參數

Constructors are lazy

建構子應該只傳參數。不要在建構時就做了一堆的事。下面的code 就不好。

  public class XmlFile
  {
    string data;
    public XmlFile(string filename)
    {
      data = File.ReadAllText(filename);
    }
  }

該改成下面的事即可

  public class XmlFile
  {
    string filename;
    public XmlFile(string filename)
    {
      this.filename = filename;
    }

    public void DoWork()
    {
      string data = File.ReadAllText(filename);
      //do more
    }