Get value from custom fields in workflow task

 To get value from specific field of an item, you need to know the guid of that field. Following is a way to get value from custom workflow task field.

Ex.

Guid testStatusFieldId = workflowProperties.TaskList.Fields["Test Status"].Id;
var status = (string)(Q0AfterProperty.ExtendedProperties[testStatusFieldId]);
if (status == "Q1")
{
                _isQ1 = true;
}
else if (status == "Q4")
{
                _isQ4 = true;
}