/// <summary>
/// Builds the type handlers.
/// </summary>
/// <param name="store">The store.</param>
private void BuildTypeHandlers(IConfigurationStore store)
{
for (int i = 0; i < store.TypeHandlers.Length ; i++)
{
IConfiguration handlerConfig = store.TypeHandlers[i];
try
{
//_configScope.ErrorContext.Activity = "loading typeHandler";
TypeHandler handler = TypeHandlerDeSerializer.Deserialize(handlerConfig);
//configScope.ErrorContext.MoreInfo = "Check the callback attribute '" + handler.CallBackName + "' (must be a classname).";
ITypeHandler typeHandler = null;
Type type = modelStore.DataExchangeFactory.TypeHandlerFactory.GetType(handler.Callback);
object impl = Activator.CreateInstance(type);
if (impl is ITypeHandlerCallback)
{
typeHandler = new CustomTypeHandler((ITypeHandlerCallback)impl);
}
else if (impl is ITypeHandler)
{
typeHandler = (ITypeHandler)impl;
}
else
{
throw new ConfigurationException("The callBack type is not a valid implementation of ITypeHandler or ITypeHandlerCallback");
}
//configScope.ErrorContext.MoreInfo = "Check the type attribute '" + handler.ClassName + "' (must be a class name) or the dbType '" + handler.DbType + "' (must be a DbType type name).";
if (handler.DbType != null && handler.DbType.Length > 0)
{
modelStore.DataExchangeFactory.TypeHandlerFactory.Register(handler.Type, handler.DbType, typeHandler);
}
else
{
modelStore.DataExchangeFactory.TypeHandlerFactory.Register(handler.Type, typeHandler);
}
}
catch (Exception e)
{
throw new ConfigurationException(
String.Format("Error registering TypeHandler class \"{0}\" for handling .Net type \"{1}\" and dbType \"{2}\". Cause: {3}",
handlerConfig.GetAttributeValue("callback"),
handlerConfig.GetAttributeValue("type"),
handlerConfig.GetAttributeValue("dbType"),
e.Message), e);
}
}
}
/// <summary>
/// Register (add) a type handler for a type and dbType
/// 根据前两个参数 分两次获取数据 最后把dbType加入字典当中
/// </summary>
/// <param name="type">the type</param>
/// <param name="dbType">the dbType (optional, if dbType is null the handler will be used for all dbTypes)</param>
/// <param name="handler">the handler instance</param>
public void Register(Type type, string dbType, ITypeHandler handler)
{
IDictionary <string, ITypeHandler> map = null;
typeHandlerMap.TryGetValue(type, out map);
if (map == null) //如果type不存在，则加入当前对象
{
map = new Dictionary <string, ITypeHandler>();
typeHandlerMap.Add(type, map);
}
if (dbType == null)
{
if (logger.IsInfoEnabled)
{
// notify the user that they are no longer using one of the built-in type handlers
ITypeHandler oldTypeHandler = null;
map.TryGetValue(NULL, out oldTypeHandler);
if (oldTypeHandler != null)
{
// the replacement will always(?) be a CustomTypeHandler
CustomTypeHandler customTypeHandler = handler as CustomTypeHandler;
string replacement = string.Empty;
if (customTypeHandler != null)
{
// report the underlying type
replacement = customTypeHandler.Callback.ToString();
}
else
{
replacement = handler.ToString();
}
// should oldTypeHandler be checked if its a CustomTypeHandler and if so report the Callback property ???
logger.Info("Replacing type handler [" + oldTypeHandler + "] with [" + replacement + "].");
}
}
map[NULL] = handler;//意味着dbType默认的null类型 对应当前
}
else
{
map.Add(dbType, handler);//最后加入字典当中ITypeHandler处理类对象
}
}