1. 持久對(duì)象映射文件

關(guān)于持久對(duì)象映射文件，這里就不多說了，可參考nhibernate的例子和文檔。
在nhibernate源代碼的根目錄里有一個(gè)nhibernate-mapping-2.0.xsd文檔，這個(gè)文檔是nhibernate用來對(duì)映射文件進(jìn)行驗(yàn)證的，我們也可以借助相關(guān)軟件用這個(gè)文檔來驗(yàn)證映射文件的有效性。

2. 映射信息的讀取

通過Configuration類，可以用多種方式讀取映射信息，一些以Add開頭的方法就是用來加入映射信息的，這些方法最終將調(diào)用Add(XmlDocument doc)。

//** Configuration.cs **

private Hashtable classes = new Hashtable();
classes集合用于存放所有的持久對(duì)象映射信息，
它的Key為持久類的類型；Value為PermissionClass類的子類。

private void Add(XmlDocument doc) {
try {
Binder.dialect = Dialect.Dialect.GetDialect(properties);
Binder.BindRoot( doc, CreateMappings());
}
catch (MappingException me) {
log.Error("Could not compile the mapping document", me);
throw me;
} // end try/catch
}

AddDocument方法調(diào)用Binder的靜態(tài)方法BindRoot來綁定持久類映射信息。CreateMappings返回一個(gè)Mappings對(duì)象，此對(duì)象是一個(gè)簡(jiǎn)單封裝了所有映射信息集合的類。

3. 建立對(duì)象映射信息

Binder類的BindRoot用于綁定映射信息中的所有映射內(nèi)容。

//** Binder.cs **

public static void BindRoot(XmlDocument doc, Mappings model) {
// ...

foreach(XmlNode n in hmNode.SelectNodes(nsPrefix + ":class", nsmgr) ) {
RootClass rootclass = new RootClass();
Binder.BindRootClass(n, rootclass, model);
model.AddClass(rootclass);
}

// ...
}

遍歷所有的類映射節(jié)點(diǎn)，然后調(diào)用BindRootClass來綁定類映射信息，最后將類映射信息加到集合中。
其中RootClass為PermissionClass的子類。

public static void BindRootClass(XmlNode node, RootClass model, Mappings mappings) {
BindClass(node, model, mappings);

//TABLENAME
XmlAttribute tableNameNode = node.Attributes["table"];
string tableName = (tableNameNode==null)
? StringHelper.Unqualify( model.PersistentClazz.Name )
: tableNameNode.Value;

XmlAttribute schemaNode = node.Attributes["schema"];
string schema = schemaNode==null ? mappings.SchemaName : schemaNode.Value;
Table table = mappings.AddTable(schema, tableName);
model.Table = table;

// ...

PropertiesFromXML(node, model, mappings);
}

BindRootClass首先調(diào)用BindClass綁定持久類映射信息，然后調(diào)用PropertiesFromXML來綁定類屬性。

public static void BindClass(XmlNode node, PersistentClass model, Mappings mapping) {
string className = node.Attributes["name"] == null ? null : node.Attributes["name"].Value;

// class
try {
model.PersistentClazz = ReflectHelper.ClassForName(className);
}
catch ( Exception cnfe ) {
throw new MappingException( "persistent class not found", cnfe);
}

// ...
}

BindClass通過反射來取得持久對(duì)象的類型。

protected static void PropertiesFromXML(XmlNode node, PersistentClass model, Mappings mappings) {
string path = model.Name;
Table table = model.Table;

foreach(XmlNode subnode in node.ChildNodes) {
CollectionType collectType = CollectionType.CollectionTypeFromString(name);
Value value = null;
if (collectType!=null) {
value = new Value(table);
BindValue(subnode, value, true);
}
else if ( "many-to-one".Equals(name) ) {
value = new ManyToOne(table);
BindManyToOne(subnode, (ManyToOne) value, propertyName, true);
}
else if ( "any".Equals(name) ) {
value = new Any(table);
BindAny(subnode, (Any) value, true);
}
else if ( "one-to-one".Equals(name) ) {
value = new OneToOne(table, model.Identifier );
BindOneToOne(subnode, (OneToOne) value, true);
}
else if ( "property".Equals(name) ) {
value = new Value(table);
BindValue(subnode, value, true, propertyName);
}
else if ( "component".Equals(name) ) {
value = new Component(model);
BindComponent(subnode, (Component) value, reflectedClass, subpath, true, mappings);
}
else if ( "subclass".Equals(name) ) {
Subclass subclass = new Subclass(model);
BindSubclass( subnode, subclass, mappings );
}
else if ( "joined-subclass".Equals(name) ) {
Subclass subclass = new Subclass(model);
BindJoinedSubclass( subnode, subclass, mappings);
}
if ( value!=null) {
Property prop = new Property(value);
BindProperty(subnode, prop, mappings);
}
}
}

遍歷所有子節(jié)點(diǎn)，然后根據(jù)節(jié)點(diǎn)類型對(duì)進(jìn)行綁定。(注: 部分內(nèi)容已刪除)
關(guān)于屬性的映射以后有空再詳細(xì)研究，只需要知道屬性已加入到RootClass的Properties屬性就行了。