public class sendEmail {
public String subject { get; set; }
public String body { get; set; }
public blob docBody { get; set; }
public String docName { get; set; }
public List < Membres__c > membersP { get; set; }
public List < Membres__c > membersC { get; set; }
public List < Membres__c > membersCorp { get; set; }
public List < Id > idP { get; set; }
public List < Id > idC { get; set; }
public List < Id > idCorp { get; set; }

// Create a constructor that populates the Account object
public sendEmail() {

    List < Id > idP = new List < Id >();
    List < Id > idC = new List < Id >();
    List < Id > idCorp = new List < Id >();

    membersP = [select Id, Name, Contact__r.Id, Contact__c, Contact__r.Name, Contact__r.Email FROM Membres__c where RecordTypeId =: '012240000002GRv' AND Contact__r.Email != null LIMIT 1];
    membersC = [select Id, Name, Contact__r.Id, Contact__c, Contact__r.Name, Contact__r.Email FROM Membres__c where RecordTypeId =: '012240000002GSt' AND Contact__r.Email != null LIMIT 1];
    membersCorp = [select Id, Name, Contact__r.Id, Contact__c, Contact__r.Name, Contact__r.Email FROM Membres__c where RecordTypeId =: '01I24000001M8lz' AND Contact__r.Email != null LIMIT 1];

        idP.add('0032400000gKaFB');
    for (Membres__c m : membersP) {
        idP.add(m.Contact__c);
    }
    for (Membres__c m : membersC) {
        idC.add(m.Contact__c);
    }
    for (Membres__c m : membersCorp) {
        idCorp.add(m.Contact__c);
    }
}

public List < Membres__c > getMembresP() {
    return membersP;
}

public List < Membres__c > getMembresC() {
    return membersC;
}

public List < Membres__c > getMembresCorp() {
    return membersCorp;
}

// Partie Private
public PageReference sendPrivate() {

    // Création de l'email
    Messaging.MassEmailMessage email = new Messaging.MassEmailMessage();

    // Create the email attachment
    Messaging.EmailFileAttachment efa = new Messaging.EmailFileAttachment();
    efa.setFileName( docName );
    efa.setBody( docBody );

    // Gestion des paramètres généraux
    email.setTargetObjectIds( idP );
    email.setWhatIds( idP );
    email.setSubject( subject );
    email.setSenderDisplayName('URB-BKV');
    email.setTemplateID('00X24000000Mxfa');
    //email.setDescription( body );

    // Create email on contact
    email.setSaveAsActivity(true);

    // Attach document
    //email.setFileAttachments(new Messaging.EmailFileAttachment[] {efa});

    // Send Email
    //Messaging.SendEmailResult [] r = Messaging.sendEmail(new Messaging.MassEmailMessage[] {email});
    //Messaging.sendEmail(new Messaging.Email[] { email });
    Messaging.sendEmail(new Messaging.MassEmailMessage[] { email });

    return null;
}