/// <summary>
/// 两个OrderByClip相加
/// </summary>
/// <param name="leftOrderByOpt"></param>
/// <param name="rightOrderByOpt"></param>
/// <returns></returns>
public static OrderByOperation operator &(OrderByOperation leftOrderByOpt, OrderByOperation rightOrderByOpt)
{
if (IsNullOrEmpty(leftOrderByOpt) && IsNullOrEmpty(rightOrderByOpt))
{
return(None);
}
if (IsNullOrEmpty(leftOrderByOpt))
{
return(rightOrderByOpt);
}
if (IsNullOrEmpty(rightOrderByOpt))
{
return(leftOrderByOpt);
}
OrderByOperation orderby = new OrderByOperation();
foreach (KeyValuePair <string, OrderByOperater> kv in leftOrderByOpt.orderByOperation)
{
orderby.orderByOperation.Add(kv.Key, kv.Value);
}
foreach (KeyValuePair <string, OrderByOperater> kv in rightOrderByOpt.orderByOperation)
{
if (!orderby.orderByOperation.ContainsKey(kv.Key))
{
orderby.orderByOperation.Add(kv.Key, kv.Value);
}
}
return(orderby);
}
/// <summary>
/// 比较
/// </summary>
/// <param name="orderByClip"></param>
/// <returns></returns>
public bool Equals(OrderByOperation 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(OrderByOperation orderByClip)
{
if ((null == orderByClip) || string.IsNullOrEmpty(orderByClip.ToString()))
{
return(true);
}
return(false);
}
/// <summary>
/// 去掉的表前缀
/// </summary>
/// <returns></returns>
public OrderByOperation RemovePrefixTableName()
{
OrderByOperation tempOrderByClip = new OrderByOperation();
foreach (KeyValuePair <string, OrderByOperater> kv in this.orderByOperation)
{
string keyName = kv.Key;
if (kv.Key.IndexOf('.') > 0)
{
keyName = keyName.Substring(keyName.IndexOf('.') + 1);
}
tempOrderByClip.orderByOperation.Add(keyName, kv.Value);
}
return(tempOrderByClip);
}
private static OrderByOperation ToOrderByClipChild(string tableName, System.Linq.Expressions.Expression exprBody, OrderByOperater orderBy)
{
if (exprBody is MemberExpression)
{
var e = (MemberExpression)exprBody;
OrderByOperation gb = OrderByOperation.None;
var filedProp = GetFieldName(e.Member);
if (orderBy == OrderByOperater.DESC)
{
gb = gb && CreateField(tableName, filedProp, e.Expression.Type).Desc;
}
else
{
gb = gb && CreateField(tableName, filedProp, 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);
OrderByOperation gb = OrderByOperation.None;
foreach (MemberExpression member in exNew.Arguments)
{
var filedProp = GetFieldName(member.Member);
if (orderBy == OrderByOperater.DESC)
{
gb = gb && CreateField(tableName, filedProp, member.Expression.Type).Desc;
}
else
{
gb = gb && CreateField(tableName, filedProp, member.Expression.Type).Asc;
}
}
return(gb);
}
if (exprBody is UnaryExpression)
{
var ueEx = (UnaryExpression)exprBody;
return(ToOrderByClipChild(tableName, ueEx.Operand, orderBy));
}
throw new Exception("暂时不支持的Order by lambda写法！请使用经典写法！");
}
