在页面加载时，我调用了 OracleDependency 对象。它在第一次加载页面时非常适用。
表示如果与查询关联的表发生更改（某些联接表存在），则 OracleDependency OnChange 事件触发一次。这是完美的。
但是当我再次刷新页面并且在相同的表中完成的某些更改比 OracleDependency OnChange 事件触发两次时。如果刷新3次而不是 onchange 那么会激发三次。当它发射不止一个时我面临一些问题。
我经历过类似问题的解决方案，但没有运气。
代码：致电On change：
private DataTable CaseListNotification(Int64 appId, Int64 personId, string value, ref int refOpenCases, ref int refMyCases, ref int refPriorityCases, ref int refEta, string isClosedShow, string isOnholdShow)
{
OracleDependency oracleDependency = null;
//oracleConnection.Open();
OracleCommand oracleCommand = null;
OracleConnection oracleConnection = null;
OracleParameter appIdParamIn = null;
OracleParameter personIdParamIn = null;
OracleParameter casesCursorParamOut = null;
OracleParameter openCasesParam = null;
OracleParameter myCasesParam = null;
OracleParameter highPriorityCasesParam = null;
OracleParameter etaCasesParam = null;
OracleParameter isShowClosedParam = null;
OracleParameter isShowOnHoldParam = null;
DataTable dataTable = new DataTable();
try
{
oracleConnection = Connection.GetGeneralConnection();
oracleCommand = new OracleCommand("Data.get_data_list", oracleConnection);
oracleCommand.CommandType = CommandType.StoredProcedure;
appIdParamIn = new OracleParameter("p_app_id", OracleDbType.Int32, ParameterDirection.Input);
oracleCommand.Parameters.Add(appIdParamIn).Value = appId;
personIdParamIn = new OracleParameter("p_pe_id", OracleDbType.Int32, ParameterDirection.Input);
oracleCommand.Parameters.Add(personIdParamIn).Value = personId;
isShowClosedParam = new OracleParameter("p_isShow_Closed", OracleDbType.Varchar2, 1, null, ParameterDirection.Input);
oracleCommand.Parameters.Add(isShowClosedParam).Value = isClosedShow;
isShowOnHoldParam = new OracleParameter("p_isShow_OnHold", OracleDbType.Varchar2, 1, null, ParameterDirection.Input);
oracleCommand.Parameters.Add(isShowOnHoldParam).Value = isOnholdShow;
openCasesParam = CommonFunction.CreateInt32OracleParam("o_open_cases", oracleCommand, null, ParameterDirection.Output);
myCasesParam = CommonFunction.CreateInt32OracleParam("o_my_cases", oracleCommand, null, ParameterDirection.Output);
highPriorityCasesParam = CommonFunction.CreateInt32OracleParam("o_high_priority", oracleCommand, null, ParameterDirection.Output);
etaCasesParam = CommonFunction.CreateInt32OracleParam("o_eta", oracleCommand, null, ParameterDirection.Output);
casesCursorParamOut = new OracleParameter("o_case_list", OracleDbType.RefCursor);
casesCursorParamOut.Direction = ParameterDirection.Output;
oracleCommand.Parameters.Add(casesCursorParamOut);
if (value == "notification")
{
oracleCommand.Notification = null;
oracleDependency = new OracleDependency(oracleCommand);
oracleDependency.OnChange += new OnChangeEventHandler(dependency_OnChange);
oracleCommand.Notification.IsNotifiedOnce = false;
oracleCommand.AddRowid = true;
}
OracleDataAdapter oracleDataAdapter = new OracleDataAdapter(oracleCommand);
oracleDataAdapter.Fill(dataTable);
if (openCasesParam.Value != null)
refOpenCases = Convert.ToInt32(((Oracle.DataAccess.Types.OracleDecimal)(openCasesParam.Value)).Value);
if (myCasesParam.Value != null)
refMyCases = Convert.ToInt32(((Oracle.DataAccess.Types.OracleDecimal)(myCasesParam.Value)).Value);
if (highPriorityCasesParam.Value != null)
refPriorityCases = Convert.ToInt32(((Oracle.DataAccess.Types.OracleDecimal)(highPriorityCasesParam.Value)).Value);
if (etaCasesParam.Value != null)
refEta = Convert.ToInt32(((Oracle.DataAccess.Types.OracleDecimal)(etaCasesParam.Value)).Value);
Connection.ReleseGeneralConnection(oracleConnection);
return dataTable;
}
catch (Exception ex)
{
throw ex;
}
}
OnChange方法：
private void dependency_OnChange(object sender, OracleNotificationEventArgs e)
{
OracleDependency dependency = sender as OracleDependency;
// NOTE: the following code uses the normal .Net capitalization methods, though
// the forum software seems to change it to lowercase letters
dependency.OnChange -= new OnChangeEventHandler(dependency_OnChange);
new GetRecordsHub().ShowRecords();
}
程序：
PROCEDURE get_data_list(p_app_id in t_id,
p_pe_id in t_id,
p_isShow_Closed in t_name,
p_isShow_OnHold in t_name,
o_open_cases out t_id,
o_my_cases out t_id,
o_high_priority out t_id,
o_eta out t_id,
o_case_list out sys_refcursor) IS C_FUN CONSTANT t_name :='get_data_list';
BEGIN
OPEN o_case_list for
SELECT distinct ca.ca_id, ca.ca_number as CaseNumber,
cud.cud_name AS Customer, lod.lde_name AS Location,
ca.ca_summary AS Subject, pe.pe_first_name ||' ' || pe.pe_last_name AS Owner,
te.txt_display_text AS Type, ca.ca_created_date AS CreatedDate,
ca.ca_created_date AS CreatedDateForNotification,
ca.ca_updated_date AS UpdatedDate, ca.ca_updated_date AS
UpdatedDateForNotification, dr.pe_first_name ||' ' || dr.pe_last_name AS
Driver, ops.pe_first_name ||' ' || ops.pe_last_name AS OpsManager,
tepr.txt_display_text AS Priority, tere.txt_display_text AS CaseReason,
(select count(caco_id) from wb_case_comments where CACO_CA_ID = ca.ca_id)
as CmmentCounts,
(SELECT caco_comments FROM wb_case_comments
WHERE caco_id=(select max(caco_id)
from wb_case_comments
where CACO_CA_ID = ca.ca_id and
caco_app_id = p_app_id)
) as LatestComments
FROM wb_cases ca, cu_customers cud,cu_locations lo,
cu_location_dsls lod,cu_persons pe,cu_persons dr,cu_persons ops,
di_texts te,di_texts tepr,di_texts tere
where ca.ca_app_id = cud.cud_app_id AND
ca.ca_cu_id = cud.cud_cu_id and
cud.cud_is_active = 1 AND ca.ca_lo_id = lo.lo_id(+)
AND lo.lo_id = lod.lde_lo_id(+) AND
ca.ca_pe_id_owner = pe.pe_id(+) AND
ca.ca_pe_id_driver = dr.pe_id(+) AND
ca.ca_pe_id_opsmanager = ops.pe_id(+) AND
ca.ca_iv_code_status = te.txt_code(+) AND
ca.ca_iv_code_severity = tepr.txt_code(+) AND
ca.ca_iv_code_reason = tere.txt_code(+) and
ca.ca_app_id = p_app_id and lo.lo_app_id = p_app_id
and lod.lde_app_id = p_app_id and pe.pe_app_id = p_app_id
and dr.pe_app_id = p_app_id and te.txt_app_id = p_app_id
and tepr.txt_app_id = p_app_id and tere.txt_app_id = p_app_id
order by ca.ca_id desc;
请帮忙。