一段VBA代码不懂
SumIfs(Sheet3.Range("h2:h65536"), Sheet3.Range("c2:c65536"), TextBox6.Value, Sheet3.Range("P2:P65536"), "=" & "NG") - Application.WorksheetFunction.SumIfs(Sheet4.Range("h2:h65536"), Sheet4.Range("c2:c65536"), TextBox6.Value, Sheet4.Range("T2:T65536"), "=" & "NG")
这段代码什么意思?sumifs函数干吗用的?越详细越好