vb实时错误91，对象变量或者WITH块变量未设置

前两句是引用了8583那个控件
Private WithEvents Host As OpenIso8583Service.SCClient
Public Event Response(iRet As Integer, RCode As String)
这是用JSON发送数据
'查询余额
Private Function getCXYEComm() As String
Dim day As Date
Dim time As Date
day = Now
transmsn_date_time = Format(day, "yyyymmdd")
MessageType = "0200"
procode = "CXYE"
primary_acct_num = "1212121234321234312"
processing_code = "301200"
sys_trace_audit_num = "123456"
acq_inst_id_code = "12365432123"
card_accptr_termnl_id = "11110000"
pin_data = "123456"
msg_authn_code = "12341234"
CommHead = "{'MessageType':'" + MessageType + "','ProcCode':'" + procode + "','Fields':{"
CommBody = _
"'primary_acct_num':'" + primary_acct_num + _
"','processing_code':'" + processing_code + _
"','transmsn_date_time':'" + transmsn_date_time + _
"','sys_trace_audit_num':'" + sys_trace_audit_num + _
"','acq_inst_id_code':'" + acq_inst_id_code + _
"','card_accptr_termnl_id':'" + card_accptr_termnl_id + _
"','pin_data':'" + pin_data + _
"','msg_authn_code':'" + msg_authn_code + _
"'}}"
getCXYEComm = CommHead + CommBody
End Function
这是初始化那个引用的控件
Private Sub OPEN_Click()
Set Host = New OpenIso8583Service.SCClient
Host.Start
End Sub
这是按钮的内容
Private Sub CXYE_Click()
Host.Send (getCXYEComm)
End Sub