How to display a pdf page into a Flet container

I'm trying to develop a simple app for displaying each page of a Pdf file. I start by adding a container and a button. The Pdf file's full path(absolute path + file name) is given to the variable fullname. The file is converted into a list of PIL images using the pdf2image library.

I'm trying to set the first image(first element of the list) as the content of the container after a button is clicked.

Here is the code:

import flet as ft
import pdf2image


def main(page: ft.Page):
    fullname = r'Your Full Path To the Doc.pdf'
    viewer = pdf2image.convert_from_path(fullname)

    def btn_Click(e):
        cont.content = ft.Image(src = viewer[0],
            fit=ft.ImageFit.FILL,
            )
        page.update()


    cont = ft.Container(height = 0.4*page.height,
        width = 0.4 * page.width,
        border=ft.border.all(3, ft.colors.RED),)

    btn = ft.IconButton(
        icon=ft.icons.UPLOAD_FILE,
        on_click=btn_Click,
        icon_size=35,)    


    page.add(ft.Column([cont, btn], 
        horizontal_alignment="center"))
    page.window_maximized = True
    page.horizontal_alignment = "center"
    page.scroll = ft.ScrollMode.AUTO
    page.update()

ft.app(target=main, assets_dir="assets")

Why is nothing is displayed in the container and no error shown?

I moddify code to use base64 image src with flet i don't not why, but flet working bad with normal image src and use src_base64 is better choise.

import flet as ft
import pdf2image
from io import BytesIO
from PIL import Image as image
import numpy as np
import base64

import pypdf

i = 0


def main(page: ft.Page):
    fullname = r'D:\BDOT_2015.pdf'
    src_pdf = pypdf.PdfReader(fullname)


    def btn_Click(e):
        global i

        if i >= len(src_pdf.pages):
            i = 0


        out = pypdf.PdfWriter()
        out.add_page(src_pdf.pages[i])
        out.write('t.pdf')

        viewer = pdf2image.convert_from_path('t.pdf',
                                             poppler_path=r'D:\Python\PDF-ORGANIZER\PDF2TIFF\poppler-24.02.0\Library\bin')
        viewer64 = []
        for view in viewer:
            arr = np.asarray(view)
            pil_img = image.fromarray(arr)
            buff = BytesIO()
            pil_img.save(buff, format="JPEG")
            pic = base64.b64encode(buff.getvalue()).decode("utf-8")
            viewer64.append(pic)

        cont.content = ft.Image(src_base64=viewer64[0],
            fit=ft.ImageFit.FILL,
            )
        page.update()


    cont = ft.Container(expand=1,
        border=ft.border.all(3, ft.colors.RED),)

    btn = ft.IconButton(
        icon=ft.icons.UPLOAD_FILE,
        on_click=lambda e: btn_Click(e),
        icon_size=35,)

    def btn_Next(e):
        global i
        i += 1
        btn_Click(e)

    btn_n = ft.IconButton(
        icon=ft.icons.NAVIGATE_NEXT,
        on_click=lambda e: btn_Next(e),
        icon_size=35,)


    page.add(ft.Column([cont, btn, btn_n],
        horizontal_alignment=ft.MainAxisAlignment.CENTER))
    page.window_maximized = True
    page.horizontal_alignment = ft.MainAxisAlignment.CENTER
    page.scroll = ft.ScrollMode.AUTO
    page.update()

ft.app(target=main, assets_dir="assets")

Now your code working as i think you expect.