在c＃中實現策略模式時出現錯誤

Question

我正在嘗試使用嵌套類實現策略模式。

public class Restriction 
{ 
    protected SpecificRestriction _specificRestriction; 

    public void SetGreaterRestriction(decimal value) 
    { 
     Greater greaterRestriction = new Greater(); 
     greaterRestriction.GreaterValue = value; 
     _specificRestriction = greaterRestriction; 
    } 

    public void SetLessRestriction(decimal value) 
    { 
     Less lessRestriction = new Less(); 
     lessRestriction.LessValue = value; 
     _specificRestriction = lessRestriction; 
    } 

    public void SetRangeRestriction(decimal lessValue, decimal greaterValue) 
    { 
     Range r = new Range(); 
     r.GreaterValue= greaterValue; 
     r.LessValue= lessValue; 
     _specificRestriction = r; 
    } 

    public bool Eval(decimal Value2) 
    { 
     return _specificRestriction.Eval(Value2); 
    } 


    /* Nested strategies classes */ 

    protected abstract class SpecificRestriction 
    {  
     public abstract bool Eval(decimal Value); 
    } 

    protected class Less : SpecificRestriction 
    { 
     public decimal LessValue { get; set; } 
     public override bool Eval(decimal lessValue) 
     { 
      return lessValue < LessValue ; 
     } 
    } 

    protected class Greater : SpecificRestriction 
    { 
     public decimal GreaterValue { get; set; } 
     public override bool Eval(decimal greaterValue) 
     { 
      return greaterValue > GreaterValue; 
     } 
    } 

    protected class Range : SpecificRestriction 
    { 
     public decimal LessValue { get; set; } 
     public decimal GreaterValue { get; set; } 

     public override bool Eval(decimal mediumValue) 
     { 
      return LessValue <= mediumValue && mediumValue <= GreaterValue; 
     } 
    } 
} 

測試：

 Restriction r = new Restriction(); 

     r.SetLessRestriction(12); 
     r.Eval(13) // Return false <- Works! 
     r.Eval(11) // Return True <- Works! 


     r.SetGreaterRestriction(12); 
     r.Eval(13)  // Return True <- Works! 
     r.Eval(11)  // Return False <- Works! 

     r.SetRangeRestriction(12, 15); 
     r.Eval(13) // Return false  <- It does not works 
     r.Eval(11) // Return false  <- Works! 
     r.Eval(16) // Return false  <- Works! 

爲什麼射程它不工作？我在Range類中做錯了什麼？

Answer 1

中有限制等級所需的一些變化和它的作品

公共類限制 { 保護SpecificRestriction _specificRestriction;

public void SetGreaterRestriction(decimal value) 
    { 
     Greater greaterRestriction = new Greater(); 
     greaterRestriction.GreaterValue = value; 
     _specificRestriction = greaterRestriction; 
    } 

    public void SetLessRestriction(decimal value) 
    { 
     Less lessRestriction = new Less(); 
     lessRestriction.LessValue = value; 
     _specificRestriction = lessRestriction; 
    } 

    public void SetRangeRestriction(decimal lessValue, decimal greaterValue) 
    { 
     Range r = new Range(); 
     r.GreaterValue = greaterValue; 
     r.LessValue = lessValue; 
     _specificRestriction = r; 
    } 

    public bool Eval(decimal Value2) 
    { 
     return _specificRestriction.Eval(Value2); 
    } 


    /* Nested strategies classes */ 

    protected abstract class SpecificRestriction 
    { 
     public abstract bool Eval(decimal Value); 
    } 

    protected class Less : SpecificRestriction 
    { 
     public decimal LessValue { get; set; } 
     public override bool Eval(decimal lessValue) 
     { 
      return lessValue < LessValue; 
     } 
    } 

    protected class Greater : SpecificRestriction 
    { 
     public decimal GreaterValue { get; set; } 
     public override bool Eval(decimal greaterValue) 
     { 
      return greaterValue > GreaterValue; 
     } 
    } 

    protected class Range : SpecificRestriction 
    { 
     public decimal LessValue { get; set; } 
     public decimal GreaterValue { get; set; } 

     public override bool Eval(decimal mediumValue) 
     { 
      return LessValue <= mediumValue && mediumValue <= GreaterValue; 
     } 
    } 
} 

Answer 2

您的Range類不會覆蓋Eval方法，它將重寫Evaluar方法。