/// <summary>
/// 批量删除实体
/// </summary>
/// <param name="where"></param>
/// <returns></returns>
public int RemoveList(Expression <Func <T, bool> > where)
{
var temp = context.Set <T>().Where(where);
foreach (var item in temp)
{
context.Entry <T>(item).State = EntityState.Deleted;
}
return(context.SaveChanges());
}