c# - 编程策略——如何将对象向下传递到类链中

Question

我正在努力改进使用类和对象的策略。

将对象向下传递到特定类链以保持代码井井有条的最佳方式是什么。

示例:使用 ZedGraph 对象(注意)这可能不是最好的示例，但它会让想法得到理解。

class Graphhandler
{
    private ZedGraphControl ZGC;
    private SubGraphController PortionofGraph;

    public class GraphHandler(ZedGraphControl _ZGC)
    {
         ZGC = _ZGC;
         initializeGraph();
    }

    private void initializeGraph()
    {
        // notice I am putting the ZGC Object into another class
        // and likely that ZGC object will go into another class
        PortionofGraph = new SubGraphController(ZGC);
    }        
}    

class SubGraphController
{
    private ZedGraphControl ZGC;
    private DeeperSubGraphController PortionofGraph;

    public class SubGraphController(ZedGraphControl _ZGC)
    {
         ZGC = _ZGC;
         initializeSubGraph();
    }

    private void initializeSubGraph()
    {
        PortionofGraph = new DeeperSubGraphController(ZGC); 
        // is there a better way?
    }

}

有没有更好的方法通过所有这些调用向下传递 yop 级别对象来操作数据？

Answer 1

通常，答案是将完全形成的依赖项传递到您的对象中。例如:

public GraphHandler(SubGraphController portionOfGraph) {
     this.portionOfGraph = portionOfGraph;
}

public SubGraphController(DeeperSubGraphController portionOfGraph) {
     this.portionOfGraph = portionOfGraph;
}


...

var zedGraphControl = new ZedGraphControl();
var deeperSubGraphController = new DeeperSubGraphController(zedGraphControl);
var subGraphController = new SubGraphController(deeperSubGraphController);
var graphHandler = new GraphHandler(subGraphController);

而不是直接在子图 Controller 中构造 DeeperSubGraphController。如今，您通常使用依赖注入(inject)框架来协调所有这些。

(另请参阅:Dependency Injection Myth: Reference Passing)