/// <summary>
///
/// </summary>
/// <param name="enumType"></param>
/// <returns></returns>
public static EnumItemCollection Get(Type enumType)
{
EnumItemCollection enumItems = null;
if (!_typedEnumItemsCache.TryGetValue(enumType, out enumItems))
{
enumItems = GetEnumItems(enumType);
Add(enumType, enumItems);
}
return(enumItems);
}
/// <summary>
///
/// </summary>
/// <param name="enumType"></param>
/// <param name="enumItems"></param>
private static void Add(Type enumType, EnumItemCollection enumItems)
{
if (!_typedEnumItemsCache.ContainsKey(enumType))
{
lock (_syncObj)
{
if (!_typedEnumItemsCache.ContainsKey(enumType))
{
_typedEnumItemsCache.Add(enumType, enumItems);
}
}
}
}
/// <summary>
/// get the enum's all list
/// </summary>
/// <param name="enumType">the type of the enum</param>
/// <param name="withAll">identicate whether the returned list should contain the all item</param>
/// <returns></returns>
private static EnumItemCollection GetEnumItems(Type enumType)
{
EnumItemCollection emumItems = new EnumItemCollection();
if (enumType.IsEnum != true)
{
// just whethe the type is enum type
throw new InvalidOperationException();
}
// 获得特性Description的类型信息
Type typeDescription = typeof(DescriptionAttribute);
// 获得枚举的字段信息（因为枚举的值实际上是一个static的字段的值）
FieldInfo[] fields = enumType.GetFields();
// 检索所有字段
foreach (FieldInfo field in fields)
{
// 过滤掉一个不是枚举值的，记录的是枚举的源类型
if (field.FieldType.IsEnum == false)
{
continue;
}
// 通过字段的名字得到枚举的值
int value = (int)enumType.InvokeMember(field.Name, BindingFlags.GetField, null, null, null);
string description = string.Empty;
// 获得这个字段的所有自定义特性，这里只查找Description特性
object[] arr = field.GetCustomAttributes(typeDescription, true);
if (arr.Length > 0)
{
// 因为Description自定义特性不允许重复，所以只取第一个
DescriptionAttribute descriptionAttri = (DescriptionAttribute)arr[0];
// 获得特性的描述值
description = descriptionAttri.Description;
}
else
{
// 如果没有特性描述，那么就显示英文的字段名
description = field.Name;
}
emumItems.Add(new EnumItem(field.Name, value, description));
}
return(emumItems);
}
/// <summary>
/// get the Enum value according to the its decription
/// </summary>
/// <typeparam name="T">the type of the enum</typeparam>
/// <param name="description">the description of the EnumValue</param>
/// <returns></returns>
public static T GetEnumByDescription <T>(string description)
{
if (string.IsNullOrEmpty(description))
{
return(default(T));
}
Type enumType = typeof(T);
EnumItemCollection list = GetEnumItems(enumType);
foreach (EnumItem item in list)
{
if (item.Description.ToString().ToLower() == description.Trim().ToLower())
{
return((T)Enum.ToObject(typeof(T), item.Value));
}
}
return(default(T));
}
/// <summary>
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="key"></param>
/// <param name="defaultValue"></param>
/// <returns></returns>
public static T GetEnumByKey <T>(string key, T defaultValue)
{
T item = defaultValue;
EnumItem enumItem = null;
try
{
Type enumType = typeof(T);
EnumItemCollection enumItems = EnumItemsCache.Get(enumType);
enumItems.TryGet(key, out enumItem);
if (enumItem != null)
{
item = (T)Enum.ToObject(enumType, enumItem.Value);
}
}
catch
{
item = defaultValue;
}
return(item);
}
/// <summary>
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="value"></param>
/// <param name="defaultValue"></param>
/// <returns></returns>
public static T GetEnumByValue <T>(string value, T defaultValue)
{
T item = defaultValue;
try
{
EnumItemCollection enumItems = GetEnumItems(typeof(T));
foreach (EnumItem enumItem in enumItems)
{
if (enumItem.Value.ToString() == value)
{
item = (T)Enum.ToObject(typeof(T), enumItem.Value);
}
}
}
catch
{
item = defaultValue;
}
return(item);
}
/// <summary>
///
/// </summary>
/// <param name="enumField"></param>
/// <returns></returns>
public static EnumItem GetEnumItem(Enum enumField)
{
EnumItemCollection enumItems = GetEnumItems(enumField.GetType());
return(enumItems[enumField.ToString()]);
}
/// <summary>
///
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="enumField"></param>
/// <returns></returns>
public static EnumItem GetEnumItem <T>(T enumField)
{
EnumItemCollection enumItems = GetEnumItems(typeof(T));
return(enumItems[enumField.ToString()]);
}
