private void CreatBindingFromSimple(ref Tuple <Expression, Expression, bool, string> configExpression, Type typeSource, Type typeTarget, PropertyInfo propTarget)
{
// 没有特殊的操作
if (typeSource == typeTarget)
{
// 创建成员绑定
CreateMemberBinding(configExpression.Item1, propTarget, configExpression.Item3);
}
else
{
// 尝试查找mapper
MapperConfigurationBase externalMapper = GetAndCheckMapper(typeSource, typeTarget, configExpression.Item4);
// 如果此时未初始化映射器
externalMapper.CreateMappingExpression(_constructorFunc);
// 默认情况下，检查对象的null
Expression mapExpression = externalMapper.GetMemberInitExpression();
Expression defaultExpression = Expression.Constant(MapperHelper.GetDefaultValue(configExpression.Item1.Type), configExpression.Item1.Type);
// 修改成员
Expression expSource = visitorMapper.Visit(configExpression.Item1);
ChangParameterExpressionVisitor changeParamaterVisitor = new ChangParameterExpressionVisitor(expSource);
mapExpression = changeParamaterVisitor.Visit(mapExpression);
// 现在可以创建正确的参数。
Expression checkIfNull = Expression.NotEqual(expSource, defaultExpression);
// 创建条件
var checkExpression = Expression.Condition(checkIfNull, mapExpression, Expression.Constant(MapperHelper.GetDefaultValue(mapExpression.Type), mapExpression.Type), mapExpression.Type);
MemberAssignment bindExpression = Expression.Bind(propTarget, checkExpression);
// 找到了映射器但没有配置
if (string.IsNullOrEmpty(configExpression.Item4))
{
configExpression = Tuple.Create(configExpression.Item1, configExpression.Item2, configExpression.Item3, externalMapper.Name);
}
memberForNew.Add(bindExpression);
}
}
/// <summary>
/// 反向映射
/// </summary>
/// <param name="name">mapper别名</param>
/// <returns>
/// 新的mapper对象
/// </returns>
/// <exception cref="MapperExistException"></exception>
public MapperConfiguration <TDest, TSource> ReverseMap(string name = null)
{
MapperConfigurationBase map = GetMapper(typeof(TDest), typeof(TSource), false, name);
if (map != null)
{
throw new MapperExistException(typeof(TDest), typeof(TSource));
}
string finalName = string.IsNullOrEmpty(name) ? "s" + (MapperConfigurationCollectionContainer.Instance.Count).ToString() : name;
map = new MapperConfiguration <TDest, TSource>(finalName);
MapperConfigurationCollectionContainer.Instance.Add(map);
CreateCommonMember();
// 现有属性的映射，并且创建反向关系
foreach (var item in PropertiesMapping)
{
PropertyInfo propertyDest = GetPropertyInfo(item.Item1);
if (propertyDest.CanWrite)
{
if (!string.IsNullOrEmpty(item.Item4))
{
//找到反向关系的mapper
var reverseMapper = GetMapper(item.Item2.Type, item.Item1.Type, false);
if (reverseMapper != null)
{
map.ForMemberBase(item.Item2, item.Item1, item.Item3, reverseMapper.Name);
}
}
else
{
if (item.Item1.NodeType == ExpressionType.MemberAccess)
{
map.ForMemberBase(item.Item2, item.Item1, item.Item3, item.Item4);
}
}
}
}
return((MapperConfiguration <TDest, TSource>)map);
}