private Tables CreateHeads(DateTime startYears, DateTime endYearsa, out int colNum)
{
var table = new Tables();
table.AddHeadCol("供应商代码", "min-width: 125px;");
table.AddHeadCol("供应商名称", "min-width: 160px;");
table.AddHeadCol("原材料代码", "min-width: 130px;");
table.AddHeadCol("原材料名称", "min-width: 135px;");
table.AddHeadCol("价格单位", "min-width: 135px;");
colNum = 4;
while (startYears <= endYearsa)
{
table.AddHeadCol($"{startYears.ToString("yyyy-MM")}", "min-width: 85px;");
startYears = startYears.AddMonths(1);
colNum++;
}
table.AddHeadRow();
return(table);
}