The Duchess of Cambridge looked as fresh as a daisy on Friday as she arrived at Warner Bros studios in Hertforshire, along with Princes William and Harry.

Dressed in a £38 polka dot dress from Topshop, Kate seemed cheery about visiting the studios where the Harry Potter movies were produced.

The royal trio were there to officially open the studios and meet with local dignitaries and senior executives.

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The Duchess of Cambridge wore a £38 Top Shop dress

Props, costumes and models from the movies that chronicle the boy wizard's adventures were on display for the royal guests.

Also invited for the visit were 500 children, and their parents, associated with charities that have one of the royals as their patron.

Futuristic vehicles from the Dark Knight Batman trilogy, made by Warner Bros and starring Christian Bale in the lead role, were the first items on display including the Tumbler - the caped crusaders' Batmobile and his bike the Batpod.

William joked about taking over the Batman role with Josh Berger, president and managing director of Warner Brothers UK, Ireland and Spain, telling him: "Christian Bale's getting old and tired... I will stand in if I have to."

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  • BRITAIN-ROYALS-HARRY POTTER

    Britain's Catherine, Duchess of Cambridge, tries a wand during the Harry Potter Tour at the Inauguration Of Warner Bros Studios in Leavesden, north London, on April 26, 2013. AFP PHOTO/POOL/PAUL ROGERS (Photo credit should read PAUL ROGERS/AFP/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge pretend to challenge each other with their wands during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Paul Rogers - WPA Pool/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge pretend to challenge each other with their wands during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Paul Rogers - WPA Pool/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge pretend to challenge each other with their wands during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Paul Rogers - WPA Pool/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince Harry, Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge raise their wands on the set used to depict Diagon Alley in the Harry Potter Films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince Harry, Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge raise their wands on the set used to depict Diagon Alley in the Harry Potter Films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge looks at the costume for the character Hagrid on display on the set used to depict Hogwart's 'Great Hall' in the Harry Potter films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince Harry, Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge laugh as they hold wands on the set used to depict Diagon Alley in the Harry Potter Films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince Harry, Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge raise their wands on the set used to depict Diagon Alley in the Harry Potter Films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince Harry, Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge share a joke on the set used to depict Diagon Alley in the Harry Potter Films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince Harry, Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge raise their wands on the set used to depict Diagon Alley in the Harry Potter Films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Prince Harry are presented with wands at the end of the Harry Potter Tour during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge looks at the costume for the character Hagrid on display on the set used to depict Hogwart's 'Great Hall' in the Harry Potter films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Prince Harry are presented with wands at the end of the Harry Potter Tour during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge and Prince Harry are presented with wands at the end of the Harry Potter Tour during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge share a joke on the set used to depict Diagon Alley in the Harry Potter Films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge share a joke on the set used to depict Diagon Alley in the Harry Potter Films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge watches as Prince William, Duke of Cambridge controls the 'Batpod', which was used in the Batman films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince William, Duke of Cambridge touches the 'Batpod', which was used in the Batman films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge (R) speaks to British author J.K Rowling during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge (R) speaks to British author J.K Rowling during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge watches as Prince William, Duke of Cambridge controls the 'Batpod', which was used in the Batman films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Prince Harry walk through the set used to dipict Hogwart's 'Great Hall' in the Harry Potter films during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Prince Harry smile during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge (R) watches as Prince William, Duke of Cambridge sits on the 'Batpod' during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    HERTFORDSHIRE, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge attends the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in Hertfordshire, England. (Photo by Eamonn M. McCormack/Getty Images)

  • BRITAIN-ROYALS-HARRY POTTER

    Catherine, The Duchess of Cambridge arrives for a visit at the Warner Brother's studio in Leavesden on April 26, 2013. AFP PHOTO/POOL/CHRIS JACKSON (Photo credit should read Chris Jackson/AFP/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridg during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    HERTFORDSHIRE, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge attends the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in Hertfordshire, England. (Photo by Eamonn M. McCormack/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    HERTFORDSHIRE, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge attends the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in Hertfordshire, England. (Photo by Eamonn M. McCormack/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge watches as Prince William, Duke of Cambridge sits on the 'Batpod' during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Prince William, Duke of Cambridge, Catherine, Duchess of Cambridge and Prince Harry laugh during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge (R) watches as Prince William, Duke of Cambridge sits on the 'Batpod' during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge (R) watches as Prince William, Duke of Cambridge sits on the 'Batpod' during the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • The Duke And Duchess Of Cambridge And Prince Harry Attend The Inauguration Of Warner Bros. Studios Leavesden

    LONDON, ENGLAND - APRIL 26: Catherine, Duchess of Cambridge arrives at the Inauguration Of Warner Bros. Studios Leavesden on April 26, 2013 in London, England. (Photo by Chris Jackson/Getty Images)

  • BRITAIN-ROYALS-HARRY POTTER

    Prince William, The Duke of Cambridge (L), Catherine, The Duchess of Cambridge (2-L) and Prince Harry arrive for a visit at the Warner Brother's studio in Leavesden on April 26, 2013. AFP PHOTO/POOL/CHRIS JACKSON (Photo credit should read Chris Jackson/AFP/Getty Images)

  • BRITAIN-ROYALS-HARRY POTTER

    Prince William, The Duke of Cambridge (R) and Catherine, The Duchess of Cambridge arrive for a visit at the Warner Brother's studio in Leavesden on April 26, 2013. AFP PHOTO/POOL/CHRIS JACKSON (Photo credit should read Chris Jackson/AFP/Getty Images)

  • BRITAIN-ROYALS-HARRY POTTER

    Catherine, The Duchess of Cambridge arrives for a visit at the Warner Brother's studio in Leavesden on April 26, 2013. AFP PHOTO/POOL/CHRIS JACKSON (Photo credit should read Chris Jackson/AFP/Getty Images)

  • BRITAIN-ROYALS-HARRY POTTER

    Catherine, The Duchess of Cambridge (2-L) and Prince Harry arrive for a visit at the Warner Brother's studio in Leavesden on April 26, 2013. AFP PHOTO/POOL/CHRIS JACKSON (Photo credit should read Chris Jackson/AFP/Getty Images)

  • BRITAIN-ROYALS-HARRY POTTER

    Prince William, The Duke of Cambridge (L), Catherine, The Duchess of Cambridge (2-L) and Prince Harry (3-L) arrive for a visit at the Warner Brother's studio in Leavesden on April 26, 2013. AFP PHOTO/POOL/CHRIS JACKSON (Photo credit should read Chris Jackson/AFP/Getty Images)

  • Britain's Kate the Duchess of Cambridge arrives with her husband Prince William and his brother Prince Harry, not pictured, to attend the inauguration of "Warner Bros. Studios Leavesden" near Watford, approximately 18 miles north west of central London, Friday, April 26, 2013. As well as attending the inauguration Friday at the former World War II airfield site, the royals will undertake a tour of Warner Bros. "Studio Tour London - The Making of Harry Potter", where they will view props, costumes and models from the Harry Potter film series. (AP Photo/Chris Jackson, Pool)

  • Britain's Kate the Duchess of Cambridge stands with her husband Prince William, left, and his brother Prince Harry, right, as they are greeted upon their arrival to attend the inauguration of "Warner Bros. Studios Leavesden" near Watford, approximately 18 miles north west of central London, Friday, April 26, 2013. As well as attending the inauguration Friday at the former World War II airfield site, the royals will undertake a tour of Warner Bros. "Studio Tour London - The Making of Harry Potter", where they will view props, costumes and models from the Harry Potter film series. (AP Photo/Matt Dunham)

  • Britain's Kate the Duchess of Cambridge arrives with her husband Prince William and his brother Prince Harry, both not pictured, to attend the inauguration of "Warner Bros. Studios Leavesden" near Watford, approximately 18 miles north west of central London, Friday, April 26, 2013. As well as attending the inauguration Friday at the former World War II airfield site, the royals will undertake a tour of Warner Bros. "Studio Tour London - The Making of Harry Potter", where they will view props, costumes and models from the Harry Potter film series. (AP Photo/Chris Jackson, Pool)

  • Britain's Kate the Duchess of Cambridge arrives with her husband Prince William, left, and his brother Prince Harry, right, to attend the inauguration of "Warner Bros. Studios Leavesden" near Watford, approximately 18 miles north west of central London, Friday, April 26, 2013. As well as attending the inauguration Friday at the former World War II airfield site, the royals will undertake a tour of Warner Bros. "Studio Tour London - The Making of Harry Potter", where they will view props, costumes and models from the Harry Potter film series. (AP Photo/Chris Jackson, Pool)

  • Britain's Kate the Duchess of Cambridge arrives with her husband Prince William, not pictured and his brother Prince Harry, rear right, to attend the inauguration of "Warner Bros. Studios Leavesden" near Watford, approximately 18 miles north west of central London, Friday, April 26, 2013. As well as attending the inauguration Friday at the former World War II airfield site, the royals will undertake a tour of Warner Bros. "Studio Tour London - The Making of Harry Potter", where they will view props, costumes and models from the Harry Potter film series. (AP Photo/Chris Jackson, Pool)

  • Britain's Kate the Duchess of Cambridge arrives with her husband Prince William and his brother Prince Harry, both not pictured, to attend the inauguration of "Warner Bros. Studios Leavesden" near Watford, approximately 18 miles north west of central London, Friday, April 26, 2013. As well as attending the inauguration Friday at the former World War II airfield site, the royals will undertake a tour of Warner Bros. "Studio Tour London - The Making of Harry Potter", where they will view props, costumes and models from the Harry Potter film series. (AP Photo/Matt Dunham)

  • Britain's Kate the Duchess of Cambridge arrives with her husband Prince William and his brother Prince Harry, both not pictured, to attend the inauguration of "Warner Bros. Studios Leavesden" near Watford, approximately 18 miles north west of central London, Friday, April 26, 2013. As well as attending the inauguration Friday at the former World War II airfield site, the royals will undertake a tour of Warner Bros. "Studio Tour London - The Making of Harry Potter", where they will view props, costumes and models from the Harry Potter film series. (AP Photo/Matt Dunham)

  • Britain's Kate the Duchess of Cambridge arrives with her husband Prince William and his brother Prince Harry, both not pictured, to attend the inauguration of "Warner Bros. Studios Leavesden" near Watford, approximately 18 miles north west of central London, Friday, April 26, 2013. As well as attending the inauguration Friday at the former World War II airfield site, the royals will undertake a tour of Warner Bros. "Studio Tour London - The Making of Harry Potter", where they will view props, costumes and models from the Harry Potter film series. (AP Photo/Matt Dunham)

  • Britain's Kate the Duchess of Cambridge arrives with her husband Prince William and his brother Prince Harry, both not pictured, to attend the inauguration of "Warner Bros. Studios Leavesden" near Watford, approximately 18 miles north west of central London, Friday, April 26, 2013. As well as attending the inauguration Friday at the former World War II airfield site, the royals will undertake a tour of Warner Bros. "Studio Tour London - The Making of Harry Potter", where they will view props, costumes and models from the Harry Potter film series. (AP Photo/Matt Dunham)

William could not resist jumping on the Batpod and he leaned forward and gripped the handlebars of the vehicle as Harry and Kate looked on.

The Duke joked "Where's the start button?", adding "It's awesome, absolutely incredible" while his younger brother put his fingers beside his head for Batman's ears and said "You need the ears".

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The fun with the boys' toys continued with the nearby Batmobile as William smiled and clambered inside.

Harry peered into the hatch as his brother made himself comfortable next to a studio worker. Then he stuck his fingers in his ears as the vehicle, which has a 5.7-litre engine with 350bhp, was revved hards.

When William finally emerged, he said: "I'm a very happy man" but he then spotted his wife and apologised, saying: "Sorry, sorry".

It's been a busy week for the pregnant 31-year-old, who this week travelled to Manchester to launch a counselling programme, and addressed a crowd at the National Portrait Gallery to celebrate the work of The Art Room charity.