CRM 4.0: Reopen or reactivate a closed task / activity with SDK

Once a time Some tasks and opportunities closed wrongly in CRM4.0, so I need to reopen all these tasks and opportunity, to do this you will follow some steps:


Task: loop through for all the selected tasks
foreach (BusinessEntity TaskEntity in result.BusinessEntities)
{
try
{
task objtaskEntity = (task)TaskEntity;
task objtaskEntity1 = (task)TaskEntity;

//Create the request of the Task for State
SetStateTaskRequest objtask = new SetStateTaskRequest();
objtask.EntityId = new Guid(objtaskEntity.activityid.Value.ToString());
objtask.TaskState = 0;
objtask.TaskStatus = 2;
//Execute the request
SetStateTaskResponse res = (SetStateTaskResponse)service.Execute(objtask);


//You need to update the attribute of task entity then use the following line of code
objtaskEntity1.category = string.Empty;
service.Update(objtaskEntity1);
break;
}
catch(Exception ex)
{
continue;
}
}

Opportunity: to update or reopen Opportunity you will follow the following line of code

Picklist plSalesStage = new Picklist();
lSalesStage.Value = 1;
RenOpp.salesstagecode = plSalesStage;

OpportunityStateInfo objstateinfo = new OpportunityStateInfo();
objstateinfo.Value = OpportunityState.Open;
RenOpp.statecode = objstateinfo;
service.Update(RenOpp);