/// <summary>
/// 依次比较两个实例中需要比较的字段的指
/// </summary>
/// <param name="item2"></param>
/// <returns></returns>
public bool IsDifferent(CompareItem <T1, T2> item2)
{
foreach (var item in ColumnsValue)
{
if (item.Key != this.Option.ColumnNameOfRemove)
{
//如果对应item2的key2在item2的ColumnsValue中不存在，需要报错，可能打错列名了
string key2 = this.Option.ColumnsToCompare[item.Key];
if (!item2.ColumnsValue.ContainsKey(key2))
{
throw new Exception("Can not find the key to compare, please check your field:[ColumnsToCompare].");
}
else
{
var value1 = this.ColumnsValue[item.Key];
var value2 = item2.ColumnsValue[key2];
//TODO:此处应该实现一个根据类型比较
if (value1 is Enum)
{
int iValue1 = (int)value1;
if (!iValue1.Equals(value2))
{
return(true);
}
}
else if (value1 == null)
{
if (value2 != null)
{
return(true);
}
else
{
continue;
}
}
else if (!value1.Equals(value2))
{
return(true);
}
}
}
}
return(false);
}
public static List <CompareResultItem <T1> > Compare <T1, T2>(IEnumerable <T1> src, IEnumerable <T2> dst, CompareOption <T1, T2> option)
{
//返回结果集
var srcList = new List <CompareResultItem <T1> >();
//先构造内部用于比较的数据集
Dictionary <object, CompareItem <T1, T2> > srcCollection = new Dictionary <object, CompareItem <T1, T2> >();
foreach (var item in src)
{
if (item != null)
{
var key = option.GetSrcId(item);
var compareItem = new CompareSrcItem <T1, T2>(key, item, option);
srcCollection.Add(key, compareItem);
}
}
Dictionary <object, CompareItem <T1, T2> > dstCollection = new Dictionary <object, CompareItem <T1, T2> >();
foreach (var item in dst)
{
if (item != null)
{
var key = option.GetDstId(item);
var compareItem = new CompareDstItem <T1, T2>(key, item, option);
dstCollection.Add(key, compareItem);
}
}
//从T1的集合中查找T2的集合
//如果没找到，说明此数据从T2中删除了
//如果找到了，那么就此对比具体的成员值
//（每次找到后，要从T2集合移除，最后剩下的就全是新增的）
foreach (var item in srcCollection)
{
if (dstCollection.ContainsKey(item.Key))
{
CompareItem <T1, T2> compareItem2 = dstCollection[item.Key];
if (item.Value.IsDeleted() ||
item.Value.IsDifferent(compareItem2))
{
//目标数据集中被更新
option.ModifyItem((T1)item.Value.Item, (T2)compareItem2.Item);
srcList.Add(new CompareResultItem <T1>()
{
Item = (T1)item.Value.Item,
Result = CompareResult.Modify
});
}
dstCollection.Remove(item.Key);
}
else
{
option.RemoveItem((T1)item.Value.Item);
//目标数据集中被删除
srcList.Add(new CompareResultItem <T1>()
{
Item = (T1)item.Value.Item, Result = CompareResult.Delete
});
}
}
//最后剩下的就全是新增的（每次找到后，会从T2集合移除）
foreach (var item in dstCollection)
{
T1 t1 = option.CreateNewItem((T2)item.Value.Item);
//目标数据集中是新增的
srcList.Add(new CompareResultItem <T1>()
{
Item = t1, Result = CompareResult.New
});
}
dstCollection.Clear();
return(srcList);
}
