C#•6h ago

Loading Form crashing (Windows Form)

So im doing a pdf viewver using winform. I wanted to add a form that indicate the progression when loading the pdf pages. The problem is that the application crash during the for loop, and the loading form is not showing up before and its showing at the end of the loop but this is useless since the content is already loaded and it close immediately. I've tried many thing like using Task.Run but i cannot fix it. (pls help)

9 Replies

Silme94•6h ago

this is the loading form

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace PDF_Viewver
{
    public partial class LoadForm : Form
    {
        public int Value { get => progressBar1.Value; }

        public LoadForm(string reason)
        {
            InitializeComponent();

            reasonLabel.Text = reason;
            this.ControlBox = false;
        }

        public void UpdateValue(int value)
        {
            progressBar1.Value = value;

            if (progressBar1.Value >= 100)
            {
                this.Close();
            }
        }
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace PDF_Viewver
{
    public partial class LoadForm : Form
    {
        public int Value { get => progressBar1.Value; }

        public LoadForm(string reason)
        {
            InitializeComponent();

            reasonLabel.Text = reason;
            this.ControlBox = false;
        }

        public void UpdateValue(int value)
        {
            progressBar1.Value = value;

            if (progressBar1.Value >= 100)
            {
                this.Close();
            }
        }
    }
}

the function where i use that class

private void Convert(List<string> pages)
{
    PagesBarPanel.Controls.Clear();
    mainPDF_panel.Controls.Clear();
    pdfPages.Clear();

    int index = 0;

    LoadForm loadscreen = new LoadForm("Loading the pdf file...");
    loadscreen.Show();

    Thread.Sleep(100);

    foreach (string page in pages)
    {
        int progressValue = (int)((index + 1) * 100 / pages.Count);
        loadscreen.UpdateValue(progressValue);

        PictureBox box = new PictureBox
        {
            Size = new Size(800, 1000),
            ImageLocation = page,
            Anchor = AnchorStyles.None,
            SizeMode = PictureBoxSizeMode.Zoom
        };

        mainPDF_panel.Controls.Add(box);
        pdfPages.Add(box);

        PictureBox page_ = new PictureBox
        {
            Size = new Size(180, 251),
            ImageLocation = page,
            Anchor = AnchorStyles.None,
            SizeMode = PictureBoxSizeMode.Zoom,
            Cursor = Cursors.Hand
        };

        Label pagesNumber = new Label
        {
            Text = (index + 1).ToString(),
            ForeColor = System.Drawing.Color.Black,
            BackColor = System.Drawing.Color.Transparent,
            Margin = new Padding(0, 0, 0, 10),
            TextAlign = ContentAlignment.MiddleCenter
        };

        int currentIndex = index;
        page_.MouseDown += (sender, e) =>
        {
            if (currentIndex < mainPDF_panel.Controls.Count)
            {
                Control correspondingImage = mainPDF_panel.Controls[currentIndex];
                mainPDF_panel.ScrollControlIntoView(correspondingImage);
                UpdateSelectedPageInPagesBar(currentIndex);
                pdf.SelectedPage = currentIndex + 1;
            }
        };

        PagesBarPanel.Controls.Add(page_);
        PagesBarPanel.Controls.Add(pagesNumber);

        index++;
    }

    ResizeControls();
}

private void Convert(List<string> pages)
{
    PagesBarPanel.Controls.Clear();
    mainPDF_panel.Controls.Clear();
    pdfPages.Clear();

    int index = 0;

    LoadForm loadscreen = new LoadForm("Loading the pdf file...");
    loadscreen.Show();

    Thread.Sleep(100);

    foreach (string page in pages)
    {
        int progressValue = (int)((index + 1) * 100 / pages.Count);
        loadscreen.UpdateValue(progressValue);

        PictureBox box = new PictureBox
        {
            Size = new Size(800, 1000),
            ImageLocation = page,
            Anchor = AnchorStyles.None,
            SizeMode = PictureBoxSizeMode.Zoom
        };

        mainPDF_panel.Controls.Add(box);
        pdfPages.Add(box);

        PictureBox page_ = new PictureBox
        {
            Size = new Size(180, 251),
            ImageLocation = page,
            Anchor = AnchorStyles.None,
            SizeMode = PictureBoxSizeMode.Zoom,
            Cursor = Cursors.Hand
        };

        Label pagesNumber = new Label
        {
            Text = (index + 1).ToString(),
            ForeColor = System.Drawing.Color.Black,
            BackColor = System.Drawing.Color.Transparent,
            Margin = new Padding(0, 0, 0, 10),
            TextAlign = ContentAlignment.MiddleCenter
        };

        int currentIndex = index;
        page_.MouseDown += (sender, e) =>
        {
            if (currentIndex < mainPDF_panel.Controls.Count)
            {
                Control correspondingImage = mainPDF_panel.Controls[currentIndex];
                mainPDF_panel.ScrollControlIntoView(correspondingImage);
                UpdateSelectedPageInPagesBar(currentIndex);
                pdf.SelectedPage = currentIndex + 1;
            }
        };

        PagesBarPanel.Controls.Add(page_);
        PagesBarPanel.Controls.Add(pagesNumber);

        index++;
    }

    ResizeControls();
}

Silme94•6h ago

Cmdr. Beavis•6h ago

Have you tried creating a super bare bones repro of the problem?

Nasdack•6h ago

A WinForms crashing indicates an exception Try catch the Convert method and see what exception pops up

Silme94•5h ago

wdym? no i mean a little stop bc of the loop u see?

Nasdack•5h ago

https://paste.gg/p/anonymous/4478c9c4e76f43e8b62dbffdec9fedfa You might also need to call BeginInvoke on ResizeControls() This is a CPU bound synchronous process The Convert method execution will finish before the loading completes so make sure you take care of that

Cmdr. Beavis•5h ago

Creating a seperate app with just enough libraries, etc. to reproduce the problem, which can make debugging a LOT easier / more simple. Also (and/or), you may want to add some logging to a local db or something in case the problem isn't something you can find via "stepping through the code." Back in the day that was the first question most people trying to help you would ask. 😁

Silme94•5h ago

no but this is not rly the problem ok i will try what you sent me no... wait i can i post the project on github, install it on your machine and test it? You will have better understanding of what im trying to explain

Silme94•4h ago

@Nasdack go to Form1.cs and you will found the Convert function (it will take extracted image from pdf and add it to the form) btw you need to install Apose.PDF 1.8.4 https://github.com/Silme94/pdf

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Loading Form crashing (Windows Form)