经过几次检查，我发现表示批准或拒绝的操作ID为1 。
但是我可以使用adapter.Menu来检查名称。

After few checks, i found that the actionID is coming as 1 for Approve or Reject. But i can use adapter.Menu to check the name.

 if (adapter.Menu == "Approve")
 {
    SIApprovalInfo.updateNextApprover(this.Base);        
 }