ADOQuery.Locate 更新解决方法

ADOQuery.Locate 更新
  我有这样的代码：
  begin
    DM_SAMPriceCopy.Qy_Detail.First;
    while not DM_SAMPriceCopy.Qy_Detail.Eof do
    begin
      if DM_SAMPriceCopy.Qy_Detail.Locate('ProcessID',QryDataDetail.FieldByName('ProcessID').AsInteger,[]) then
      begin
        QryDataDetail.Edit;
        QryDataDetail.FieldByName('ActuallyPrice').AsFloat:=DM_SAMPriceCopy.Qy_Detail.FieldByName('ActuallyPrice').AsFloat;
        QryDataDetail.Post;
      end;
      DM_SAMPriceCopy.Qy_Detail.Next;
    end;
  end;
   将DM_SAMPriceCopy.Qy_Detail开启，然后用Locate定位相同的ProcessID,如果存在，则更新QryDataDetail的ActuallyPrice。但是我通过调试发现，它出现了死循环，Next之后，获取的ProcessID都是一样的。
   请问该如何做？
[解决办法]
begin
    DM_SAMPriceCopy.Qy_Detail.First;
    while not DM_SAMPriceCopy.Qy_Detail.Eof do
    begin
      if DM_SAMPriceCopy.Qy_Detail.Locate('ProcessID',QryDataDetail.FieldByName('ProcessID').AsInteger,[]) then
      begin
        QryDataDetail.Edit;
        QryDataDetail.FieldByName('ActuallyPrice').AsFloat:=DM_SAMPriceCopy.Qy_Detail.FieldByName('ActuallyPrice').AsFloat;
        QryDataDetail.Post;
        QryDataDetail.Next;
      end;
      DM_SAMPriceCopy.Qy_Detail.Next;
    end;
  end;