SharpDevelop学习笔记--什么是codon,与codon的创建过程

codon只是一个xml文件(addin文件中)的一个节点,这个节点须有唯一的名字
以下是一个codon的创建过程,并不包括condtion

以下是调用的程序正常执行步骤的记录


public class Addin




...{


//从addin文件中分析出extension


public void Initialize(string fileName)




...{




switch (curEl.Name) ...{


case "Runtime":


AddRuntimeLibraries(Path.GetDirectoryName(fileName), curEl);


break;


case "Extension":


AddExtensions(curEl);


break;


}


}




void AddExtensions(XmlElement el)




...{




if (el.Attributes["path"] == null) ...{


throw new AddInLoadException("One extension node has no path attribute defined.");


}


Extension e = new Extension(el.Attributes["path"].InnerText);//extension的path属性


AddCodonsToExtension(e, el, new ConditionCollection());//调用此函数来实例化,条件,与Icodon


extensions.Add(e);


}




void AddCodonsToExtension(Extension e, XmlElement el, ConditionCollection conditions)




...{




foreach (object o in el.ChildNodes) ...{




if (!(o is XmlElement)) ...{


continue;


}


XmlElement curEl = (XmlElement)o;






switch (curEl.Name) ...{


case "And": // these nodes are silently ignored.


case "Or":


case "Not":


case "Condition":


break;


case "Conditional":


//建立conditional 集合


default:


ICodon codon = AddInTreeSingleton.AddInTree.CodonFactory.CreateCodon(this, curEl);//创建类的实例


}






//调用codonfactory


public class CodonFactory




...{


public ICodon CreateCodon(AddIn addIn, XmlNode codonNode)




...{


CodonBuilder builder = codonHashtable[codonNode.Name] as CodonBuilder;






if (builder != null) ...{


return builder.BuildCodon(addIn);//创建类的实例


}




throw new CodonNotFoundException(String.Format("no codon builder found for <{0}>", codonNode.Name));


}


}






//类的condonbuilder


public class CodonBuilder




...{


public ICodon BuildCodon(AddIn addIn)




...{


ICodon codon;




try ...{


// create instance (ignore case)


codon = (ICodon)assembly.CreateInstance(ClassName, true);//调用assembly来创建类的实例,并转换为icodon接口




// set default values


codon.AddIn = addIn;




} catch (Exception) ...{


codon = null;


}


return codon;


}


}