/// <summary>
/// 合并NewExpression
/// </summary>
/// <param name="exps">要合并的NewExpression</param>
public static Expression MergeNewExpression(params Expression[] exps)
{
// 获取表达式树中实体类型
var parentType = new GetParamVisitor().Visit(exps[0]).Select(o => o.Type).First();
// 取得所有PropertyInfo
var lst = new GetMemberVisitor().Visit(exps).Select(o => (PropertyInfo)o.Member);
// 构造函数参数类型
var lstPropertyType = lst.Select(o => o.PropertyType).ToArray();
// 根据取得的PropertyInfo列表，创建新类型
var classType = DynamicsClassTypeCacheManger.Cache(null, lstPropertyType, parentType);
// 获取新类型的构造函数
var constructor = classType.GetConstructor(lstPropertyType);
// 创建构造函数的参数表达式数组
var constructorParam = BuildConstructorsParameters(classType, lst);
return(Expression.New(constructor, constructorParam));
}
/// <summary>
/// 初始化逻辑删除
/// </summary>
/// <param name="defineType">实体类型</param>
public void Init(Type defineType)
{
Type fieldType;
switch (FieldType)
{
case eumSortDeleteType.Number:
fieldType = Value.GetType();
break;
case eumSortDeleteType.DateTime:
fieldType = typeof(DateTime);
Value = DateTime.Now;
break;
default:
fieldType = typeof(bool);
break;
}
var dic = new Dictionary <string, Type>();
dic[Name] = fieldType;
// 如果当前类已包含该字段，则不创新派生类
var sortDeleteClassType = defineType.GetProperty(Name) != null ? defineType : DynamicsClassTypeCacheManger.Cache(dic, defineType);
var param = Expression.Parameter(sortDeleteClassType, "o");
var member = Expression.MakeMemberAccess(param, sortDeleteClassType.GetMember(Name)[0]);
// 时间类型字段，则以参数形式（解析时动态转为当前时间）
if (FieldType == eumSortDeleteType.DateTime)
{
AssignExpression = Expression.Assign(member, Expression.Parameter(fieldType)); //DateTime.Now
CondictionExpression = Expression.Equal(member, Expression.Convert(Expression.Constant(null), fieldType));
}
else
{
var valConstant = Expression.Constant(Value, member.Type);
AssignExpression = Expression.Assign(member, valConstant);
CondictionExpression = Expression.NotEqual(member, valConstant);
}
CondictionExpression = Expression.Lambda(CondictionExpression, param);
}