/// <summary>
/// 得到某个数据类型的缺省值
/// </summary>
/// <param name="type">类型</param>
/// <returns>该类型的缺省值</returns>
/// <remarks>如果该类型为引用类型，则返回null，否则返回值类型的缺省值。如Int32返回0，DateTime返回DateTime.MinValue</remarks>
public static object GetTypeDefaultValue(System.Type type)
{
ExceptionHelper.FalseThrow <ArgumentNullException>(type != null, "type");
object result = null;
if (type.IsValueType)
{
if (TypeDefaultValueCacheQueue.Instance.TryGetValue(type, out result) == false)
{
result = TypeCreator.CreateInstance(type);
TypeDefaultValueCacheQueue.Instance.Add(type, result);
}
}
else
{
result = null;
}
return(result);
}
/// <summary>
/// 根据Request的参数得到可收集参数的值
/// </summary>
/// <param name="reqParams"></param>
/// <param name="parameterType"></param>
/// <returns></returns>
private static object GetCollectedParameterInstance(NameValueCollection reqParams, System.Type parameterType)
{
object graph = TypeCreator.CreateInstance(parameterType);
Dictionary <string, PropertyInfo> propertyDict = TypeFlattenHierarchyPropertiesCacheQueue.Instance.GetPropertyDictionary(parameterType);
propertyDict.ForEach(kp =>
{
PropertyInfo pi = kp.Value;
if (pi.CanWrite)
{
object targetValue = ChangeRequestValueToTargetType(pi.Name, reqParams, pi.PropertyType);
if (targetValue != null)
{
pi.SetValue(graph, targetValue, null);
}
}
});
return(graph);
}
/// <summary>
/// 根据类型信息创建对象，该对象即使没有公有的构造方法，也可以创建实例
/// </summary>
/// <param name="type">创建类型时的类型信息</param>
/// <param name="constructorParams">创建实例的初始化参数</param>
/// <returns>实例对象</returns>
/// <remarks>运用晚绑定方式动态创建一个实例</remarks>
public static object CreateSerializableInstance(System.Type type, params object[] constructorParams)
{
type.IsSerializable.FalseThrow <SerializationException>("XElementFormatter错误，类型{0}不可序列化", type.AssemblyQualifiedName);
return(TypeCreator.CreateInstance(type, constructorParams));
}
