System::SharedPtr<Project> project = System::MakeObject<Project>(dataDir + u"WriteUpdatedExtendedAttributeDefinitions.mpp");
        
        
// C# preprocessor directive: #region task attributes
        
        
// Add new text3 extended attribute with lookup and one lookup value
System::SharedPtr<ExtendedAttributeDefinition> taskTextAttributeDefinition = ExtendedAttributeDefinition::CreateLookupTaskDefinition(Aspose::Tasks::ExtendedAttributeTask::Text3, u"New text3 attribute");
taskTextAttributeDefinition->set_ElementType(Aspose::Tasks::ElementType::Task);
project->get_ExtendedAttributes()->Add(taskTextAttributeDefinition);
        
System::SharedPtr<Value> textVal = System::MakeObject<Value>();
textVal->set_Id(1);
textVal->set_Description(u"Text value descr");
textVal->set_Val(u"Text value1");
        
taskTextAttributeDefinition->AddLookupValue(textVal);
        
// Add new cost1 extended attribute with lookup and two cost values
System::SharedPtr<ExtendedAttributeDefinition> taskCostAttributeDefinition = ExtendedAttributeDefinition::CreateLookupTaskDefinition(Aspose::Tasks::ExtendedAttributeTask::Cost1, u"New cost1 attribute");
project->get_ExtendedAttributes()->Add(taskCostAttributeDefinition);
        
System::SharedPtr<Value> costVal1 = System::MakeObject<Value>();
costVal1->set_Id(2);
costVal1->set_Description(u"Cost value 1 descr");
costVal1->set_Val(u"99900");
        
System::SharedPtr<Value> costVal2 = System::MakeObject<Value>();
costVal2->set_Id(3);
costVal2->set_Description(u"Cost value 2 descr");
costVal2->set_Val(u"11100");
        
taskCostAttributeDefinition->AddLookupValue(costVal1);
taskCostAttributeDefinition->AddLookupValue(costVal2);
        
// Add new task and assign attribute lookup value.
System::SharedPtr<Task> task = project->get_RootTask()->get_Children()->Add(u"New task");
        
System::SharedPtr<ExtendedAttribute> taskAttr = taskCostAttributeDefinition->CreateExtendedAttribute(costVal1);
task->get_ExtendedAttributes()->Add(taskAttr);
        
System::SharedPtr<ExtendedAttributeDefinition> taskStartAttributeDefinition = ExtendedAttributeDefinition::CreateLookupTaskDefinition(Aspose::Tasks::ExtendedAttributeTask::Start7, u"New start 7 attribute");
        
System::SharedPtr<Value> startVal = System::MakeObject<Value>();
startVal->set_Id(4);
startVal->set_DateTimeValue(System::DateTime::get_Now());
startVal->set_Description(u"Start 7 value description");
        
taskStartAttributeDefinition->AddLookupValue(startVal);
        
project->get_ExtendedAttributes()->Add(taskStartAttributeDefinition);
        
System::SharedPtr<ExtendedAttributeDefinition> taskFinishAttributeDefinition = ExtendedAttributeDefinition::CreateLookupTaskDefinition(Aspose::Tasks::ExtendedAttributeTask::Finish4, u"New finish 4 attribute");
        
System::SharedPtr<Value> finishVal = System::MakeObject<Value>();
finishVal->set_Id(5);
finishVal->set_DateTimeValue(System::DateTime::get_Now());
finishVal->set_Description(u"Finish 4 value description");
        
taskFinishAttributeDefinition->get_ValueList()->Add(finishVal);
        
project->get_ExtendedAttributes()->Add(taskFinishAttributeDefinition);
        
System::SharedPtr<ExtendedAttributeDefinition> numberAttributeDefinition = ExtendedAttributeDefinition::CreateLookupTaskDefinition(Aspose::Tasks::ExtendedAttributeTask::Number20, u"New number attribute");
        
System::SharedPtr<Value> val1 = System::MakeObject<Value>();
val1->set_Id(6);
val1->set_Val(u"1");
val1->set_Description(u"Number 1 value");
System::SharedPtr<Value> val2 = System::MakeObject<Value>();
val2->set_Id(7);
val2->set_Val(u"2");
val2->set_Description(u"Number 2 value");
System::SharedPtr<Value> val3 = System::MakeObject<Value>();
val2->set_Id(8);
val3->set_Val(u"3");
val3->set_Description(u"Number 3 value");
        
numberAttributeDefinition->AddLookupValue(val1);
numberAttributeDefinition->AddLookupValue(val2);
numberAttributeDefinition->AddLookupValue(val3);
        
project->get_ExtendedAttributes()->Add(numberAttributeDefinition);
        
        
// C# preprocessor directive: #endregion
        
        
System::SharedPtr<ExtendedAttributeDefinition> rscStartAttributeDefinition = ExtendedAttributeDefinition::CreateLookupResourceDefinition(Aspose::Tasks::ExtendedAttributeResource::Start5, u"New start5 attribute");
        
System::SharedPtr<Value> startVal2 = System::MakeObject<Value>();
startVal2->set_Id(9);
startVal2->set_DateTimeValue(System::DateTime::get_Now());
startVal2->set_Description(u"this is start5 value descr");
        
rscStartAttributeDefinition->AddLookupValue(startVal2);
        
project->get_ExtendedAttributes()->Add(rscStartAttributeDefinition);
        
// Define a duration attribute without lookup.
System::SharedPtr<ExtendedAttributeDefinition> taskDurationAttributeDefinition = ExtendedAttributeDefinition::CreateTaskDefinition(Aspose::Tasks::ExtendedAttributeTask::Duration1, u"New Duration");
project->get_ExtendedAttributes()->Add(taskDurationAttributeDefinition);
        
// Add new task and assign duration value to the previously defined duration attribute.
System::SharedPtr<Task> timeTask = project->get_RootTask()->get_Children()->Add(u"New task");
        
System::SharedPtr<ExtendedAttribute> durationExtendedAttribute = taskDurationAttributeDefinition->CreateExtendedAttribute();
        
durationExtendedAttribute->set_DurationValue(project->GetDuration(3.0, Aspose::Tasks::TimeUnitType::Hour));
timeTask->get_ExtendedAttributes()->Add(durationExtendedAttribute);
        
System::SharedPtr<MPPSaveOptions> mppSaveOptions = System::MakeObject<MPPSaveOptions>();
mppSaveOptions->set_WriteViewData(true);
        
// Save the project as MPP project file
project->Save(dataDir + u"WriteUpdatedExtendedAttributeDefinitions_out.mpp", mppSaveOptions);