使用Delphi 2005,我有一个TwwDBGrid(InfoPower),允许用户选择零件数量来生成报价。部分选择过程是允许用户为由DiscountAmount和DiscountType组成的每个部分添加折扣。 DiscountAmount是折扣金额,DiscountType是折扣金额类型(折扣,折扣或平价)。这些数据保存在一个名为ClientDataSetParts的ClientDataSet中。OnCalcFields导致StackOverflow
在OnCalc方法(ClientDataSetPartsCalcFields)中,我有以下代码将根据零件成本和任何折扣重新计算TotalPrice。 RangePricing在其中一个价格是基于数量的范围内(即,1-100 = $ 100 101-200 = $ 150等)内计算的情况下使用:
procedure TfrmCustom_Services.ClientDataSetPartsCalcFields(
DataSet: TDataSet);
begin
inherited;
// if part is selected then calculate Total
if (ClientDataSetPartsSelected.Value) then begin
// if range pricing is defined
if (ClientDataSetParts.FieldByName('RangePricing').AsBoolean) then begin
ClientDataSetParts.FieldByName('TotalPrice').Value :=
ClientDataSetParts.FieldbyName('UnitPrice').Value;
// otherwise use regular pricing
end else begin
ClientDataSetParts.FieldByName('TotalPrice').Value :=
ClientDataSetParts.FieldbyName('UnitPrice').Value *
ClientDataSetParts.FieldByName('Quantity').Value;
end;
// otherwise clear the Total
end else begin
ClientDataSetParts.FieldByName('TotalPrice').Clear;
if (ClientDataSetParts.FieldByName('Quantity').Value <> null) then
ClientDataSetParts.FieldByName('Quantity').Clear;
if (ClientDataSetParts.FieldByName('DiscountAmount').Value <> null) then
ClientDataSetParts.FieldByName('DiscountAmount').Clear;
if (ClientDataSetParts.FieldByName('DiscountType').Value <> null) then
ClientDataSetParts.FieldByName('DiscountType').Clear;
end;
// Update totals if Discount is applied
// Only recalculate if both discount value and type are applied
// otherwise will constantly get errors when switching fields
if ((ClientDataSetPartsDiscountAmount.Value > 0) and (ClientDataSetPartsDiscountType.Value <> '')) then begin
case StringToCaseSelect((ClientDataSetPartsDiscountType.Value), ['% Disc','$ Disc','Price']) of
0 :
begin
ClientDataSetParts.FieldByName('DiscountDollarAmount').Value :=
ClientDataSetParts.FieldByName('TotalPrice').Value * (ClientDataSetParts.FieldByName('DiscountAmount').Value/100);
ClientDataSetPartsTotalPrice.Value := ClientDataSetPartsTotalPrice.Value - (ClientDataSetPartsTotalPrice.Value * (ClientDataSetPartsDiscountAmount.Value/100));
end;
1 :
begin
ClientDataSetParts.FieldByName('DiscountDollarAmount').Value := ClientDataSetPartsDiscountAmount.Value;
ClientDataSetPartsTotalPrice.Value := ClientDataSetPartsTotalPrice.Value - ClientDataSetPartsDiscountAmount.Value;
end;
2 :
begin
ClientDataSetParts.FieldByName('DiscountDollarAmount').Value :=
ClientDataSetPartsTotalPrice.Value - ClientDataSetPartsDiscountAmount.Value;
ClientDataSetPartsTotalPrice.Value := ClientDataSetPartsDiscountAmount.Value;
end;
end;
end;
end;
问题是当我尝试计算DiscountDollarAmount(折扣的实际美元数字,我必须通过API返回到外部来源)。每次我设置ClientDataSetParts.FieldByName('DiscountDollarAmount')。值时,ClientDataSetPartsCalcFields被再次调用,导致无尽的调用并最终导致堆栈溢出。
如何在不递回调用ClientDataSetPartsCalcFields的情况下更新此值?
您是否尝试过将AutoCalcFields设置为false? –
不改变任何东西。 – BrianKE
好的。但是请阅读关于'AutoCalcFields'的文档,或许它会提供一些见解。 –