Hello , 

I have a detail page of a cutom object named "Projet__c" .In the controller I 'am using 

System.currentPagereference().getParameters().get('id');

 In the Test Class am Using .Put(ID) but i can't Cover Lines Here is the Class controller : 

public without sharing class MADEL_DetailProjet 
{
    public Projet__c projet {get;set;}
    public List<Article__c> lstarticles{get;set;}
    public List<Equipedeprojet__c> lstequipesprojets{get;set;}

    public Map<Id,MADEL_Contact__c> mapContent  {set;get;}
    public List <Id> contactIds =new List<Id>();
    public List <MADEL_Contact__c > contactsMADEL =new List<MADEL_Contact__c>();
    public string projectid{get;set;}
    
    
     
    MADEL_Contact__c contact{get;set;}
    

    public MADEL_DetailProjet() 
    {
        
    try{
    projectid = System.currentPagereference().getParameters().get('id');
       if(projectid!=null)
       { projet = [SELECT id,Name,Datededebut__c,Datedepublication__c,Dureeestime__c,Thematique__c,SousThematique__c,Rue__c,Ville__c,Region__c,Codepostal__c,Pays__c,Longitude__c,Latitude__c   FROM Projet__c WHERE id = :projectid LIMIT 1];
        
        lstarticles=[select Id ,Name,Type__c,Lien__c,ProfessionnelduMedia__c From Article__c where Projet__c= :projectid];
        
        lstequipesprojets=[select Id ,Name,Membre__c,Projet__r.Name,Role__c,MembreMADEL__r.Name,MembreMADEL__r.GSM1__c From Equipedeprojet__c where Projet__c= :projectid];
       
       if(lstequipesprojets.size()>0)
       {
        for(Equipedeprojet__c equipe:lstequipesprojets)
        {
          contactIds.add(equipe.Membre__c);
  
        }
       }
       }
         contactsMADEL=[select Id, Name,GSM1__c,Idcontactstd__c  from MADEL_Contact__c where Idcontactstd__c IN : contactIds ];
             Map<Id,MADEL_Contact__c> mapResult = new Map<Id,MADEL_Contact__c>();
         
         for(MADEL_Contact__c contactmadel:contactsMADEL)
        {
        
        mapResult.put(contactmadel.Id,contactmadel);
        
     
        }
        mapContent=mapResult;
        
       
        

}

 catch (DMLException e){
     ApexPages.addMessages(e);
     system.debug('messge erreur'+e);
     }
    
    
    
    }


 
 
 
   
    
    
    
    



}

 And Test Class 

@isTest
private class Test_MADELDetailProjet {

    public static testMethod void detailProjetTest() 
    {
    	 Projet__c projet  = new Projet__c (Name='projet2012');
      insert projet;
       string projetid= projet.Id;
	  
    	
      Test.startTest();
      PageReference newpage = Page.MADEL_DetailProjet;
      
     
      MADEL_DetailProjet cls = new MADEL_DetailProjet();
   
        
       newpage.getParameters().put('id',projet.Id);
       cls.projectid=projet.Id;
      Test.setCurrentPage(newpage);
      Test.setCurrentPageReference(newpage);
      
  
    	
   
    	Test.stopTest();
       
       
       
       
       
       
       
       
    }
}

 And Here is an image of line not covered