/// <summary>
/// 比较
/// </summary>
/// <param name="orderByClip"></param>
/// <returns></returns>
public bool Equals(OrderByClip orderByClip)
{
if (null == orderByClip)
{
return(false);
}
return(this.ToString().Equals(orderByClip.ToString()));
}
/// <summary>
/// 判断 OrderByClip 是否为null
/// </summary>
/// <param name="orderByClip"></param>
/// <returns></returns>
public static bool IsNullOrEmpty(OrderByClip orderByClip)
{
if ((null == orderByClip) || string.IsNullOrEmpty(orderByClip.ToString()))
{
return(true);
}
return(false);
}
/// <summary>
/// 去掉的表前缀
/// </summary>
/// <returns></returns>
public OrderByClip RemovePrefixTableName()
{
OrderByClip tempOrderByClip = new OrderByClip();
foreach (KeyValuePair <string, OrderByType> kv in this.orderByClip)
{
string keyName = kv.Key;
if (kv.Key.IndexOf('.') > 0)
{
keyName = keyName.Substring(keyName.IndexOf('.') + 1);
}
tempOrderByClip.orderByClip.Add(keyName, kv.Value);
}
return(tempOrderByClip);
}
private static OrderByClip ToOrderByClipChild(System.Linq.Expressions.Expression exprBody, OrderByType orderBy)
{
if (exprBody is MemberExpression)
{
var e = (MemberExpression)exprBody;
OrderByClip gb = OrderByClip.None;
if (orderBy == OrderByType.DESC)
{
gb = gb && new Field(e.Member.Name, e.Expression.Type).Desc;
}
else
{
gb = gb && new Field(e.Member.Name, e.Expression.Type).Asc;
}
return(gb);
}
if (exprBody is NewExpression)
{
var exNew = (NewExpression)exprBody;
var type = exNew.Constructor.DeclaringType;
var list = new List <string>(exNew.Arguments.Count);
OrderByClip gb = OrderByClip.None;
foreach (MemberExpression member in exNew.Arguments)
{
if (orderBy == OrderByType.DESC)
{
gb = gb && new Field(member.Member.Name, member.Expression.Type).Desc;
}
else
{
gb = gb && new Field(member.Member.Name, member.Expression.Type).Asc;
}
}
return(gb);
}
if (exprBody is UnaryExpression)
{
var ueEx = (UnaryExpression)exprBody;
return(ToOrderByClipChild(ueEx.Operand, orderBy));
}
throw new Exception("暂时不支持的Order by lambda写法！请使用经典写法！");
}
