错误信息 Cannot resolve method Void .ctor(Int32, Int32, System.Decimal, System.Decimal) because the declaring type of the method handle System.ValueTuple`4[T1,T2,T3,T4] is generic. Explicitly provide the declaring type to GetMethodFromHandle
在本地可以运行，测试环境就不行，因为本地我装了privew 5 版本测试环境是2.1
https://github.com/dotnet/runtime/issues/29220
代码如下
public async Task<(int QtySum, int CartonsSum, decimal VolumeSum, decimal WeightSum)> GetCountSumByItemIds(List<int> itemIds)
{
// core 2.x错误示例
var result = from o in _context.Orders
join info in _context.TransportInfos on o.Id equals info.OrderId
join item in _context.TransportItems on info.Id equals item.TransportId
where itemIds.Contains(item.Id)
select new Valuetuple<int, int, decimal, decimal>(o.QuantitySum.Value, o.CartonsSum.Value, o.VolumeSum, o.WeightSum);
return await result.FirstOrDefaultAsync();
}
public async Task<(int QtySum, int CartonsSum, decimal VolumeSum, decimal WeightSum)> GetCountSumByItemIds(List<int> itemIds)
{
var result = from o in _context.Orders
join info in _context.TransportInfos on o.Id equals info.OrderId
join item in _context.TransportItems on info.Id equals item.TransportId
where itemIds.Contains(item.Id)
select new Tuple<int, int, decimal, decimal>(o.QuantitySum.Value, o.CartonsSum.Value, o.VolumeSum, o.WeightSum);
// core 2.X 不支持 在表达树中写new Valuetuple<>()
var copyTuple = await result.FirstOrDefaultAsync();
return copyTuple.ToValueTuple();
}