/// <summary>
/// 从可拓展实例中获取或创建实例;并能告知是否为新建;
/// </summary>
/// <typeparam name="TInstance"></typeparam>
/// <param name="ext"></param>
/// <param name="extName"></param>
/// <param name="factory">生产方法</param>
/// <returns>isNew指示是否为新建的实例</returns>
public static KeyValuePair <TInstance, bool> GetOrCreateInstanceInform <TInstance>(this IExtensible ext, string extName, Func <TInstance> factory)
{
if (ext == null)
{
throw new ArgumentNullException(nameof(ext));
}
if (factory == null)
{
throw new ArgumentNullException(nameof(factory));
}
var created = false;
var ins = ext.GetInstance <TInstance>(extName);
if (ins == null)
{
ins = factory();
ext.SetInstance(ins, extName);
created = true;
}
return(new KeyValuePair <TInstance, bool>(ins, created));
}
