C# PDFiumでPDFを読み込む

業務で利用するPDFを取り込んだらどうだろうと思い実験。とりあえず、ページ移動とブックマークのようなものだけ。

NuGetから、
・PdfiumViewer
・PdfiumViewer.Native.x86.v8-xfa
の２つをインストール。

using PdfiumViewer;
using System;
using System.Drawing;
using System.Windows.Forms;

namespace PDFViewer
{
    public partial class Form1 : Form
    {
        PdfDocument _Document;
        int _PageNum = 1;
        int _PageW;
        int _PageH;

        public Form1()
        {
            InitializeComponent();

            _Document = PdfDocument.Load(@"G:\Download\i.pdf");
            var size = _Document.PageSizes[0];
            _PageW = PointToPixel(size.Width);
            _PageH = PointToPixel(size.Height);

            HeaderEventAttach();
            SideEventAttach();

            RenderDocument();

            int maxPage = _Document.PageCount - 1;
            hScrollBar1.Maximum = maxPage + hScrollBar1.LargeChange - 1;
            hScrollBar1.Scroll += (s, e) =>
            {
                _PageNum = e.NewValue;
                RenderDocument();
            };
        }

        private void SideEventAttach()
        {
            MemoText.KeyDown += (s, e) =>
            {
                if (e.KeyCode != Keys.Enter) return;

                var sender = (TextBox)s;
                if (sender.Text == "") return;

                listBox1.ValueMember = "Page";
                listBox1.DisplayMember = "Title";

                listBox1.Items.Add(new {
                    Page = _PageNum.ToString(),
                    Title = sender.Text + "#" + _PageNum.ToString()
                });

                MemoText.Text = "";
            };

            listBox1.MouseDoubleClick += (s, e) =>
            {
                if (listBox1.IndexFromPoint(new Point(e.X, e.Y)) == -1) return;

                if ((ModifierKeys & Keys.Control) == Keys.Control)
                {
                    listBox1.Items.RemoveAt(listBox1.SelectedIndex);
                }
                else
                {
                    dynamic items = listBox1.SelectedItem;
                    int.TryParse(items.Page, out int result);
                    _PageNum = result;

                    RenderDocument();
                }
            };
        }

        private void HeaderEventAttach()
        {
            NextButton.Click += (s, e) =>
            {
                if (_PageNum > _Document.PageCount - 1) return;

                _PageNum++;
                RenderDocument();
                hScrollBar1.Value = _PageNum;
            };

            PrevButton.Click += (s, e) =>
            {
                if (_PageNum <= 0) return;
                
                _PageNum--;
                RenderDocument();
                hScrollBar1.Value = _PageNum;
            };

            PageNumText.KeyDown += (s, e) =>
            {
                if (e.KeyCode == Keys.Enter)
                {
                    var sender = (TextBox)s;
                    int.TryParse(sender.Text, out int result);
                    _PageNum = result;
                    RenderDocument();
                }

                if (e.KeyCode == Keys.Right)
                {
                    NextButton.PerformClick();
                    RenderDocument();
                }

                if (e.KeyCode == Keys.Left)
                {
                    PrevButton.PerformClick();
                    RenderDocument();
                }
            };
        }

        private void RenderDocument()
        {
            pictureBox1.Image = _Document.Render(_PageNum - 1, _PageW, _PageH, DeviceDpi, DeviceDpi, false);
            PageNumText.Text = Convert.ToString(_PageNum);
        }

        private int PointToPixel(float point)
        {
            return (int)(DeviceDpi * point) / 72;
        }
    }
}

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using PdfiumViewer;

using System;

using System.Drawing;

using System.Windows.Forms;

namespace PDFViewer

{

public partial class Form1 : Form

{

PdfDocument _Document;

int _PageNum = 1;

int _PageW;

int _PageH;

public Form1()

{

InitializeComponent();

_Document = PdfDocument.Load(@"G:\Download\i.pdf");

var size = _Document.PageSizes[0];

_PageW = PointToPixel(size.Width);

_PageH = PointToPixel(size.Height);

HeaderEventAttach();

SideEventAttach();

RenderDocument();

int maxPage = _Document.PageCount - 1;

hScrollBar1.Maximum = maxPage + hScrollBar1.LargeChange - 1;

hScrollBar1.Scroll += (s, e) =>

{

_PageNum = e.NewValue;

RenderDocument();

};

}

private void SideEventAttach()

{

MemoText.KeyDown += (s, e) =>

{

if (e.KeyCode != Keys.Enter) return;

var sender = (TextBox)s;

if (sender.Text == "") return;

listBox1.ValueMember = "Page";

listBox1.DisplayMember = "Title";

listBox1.Items.Add(new {

Page = _PageNum.ToString(),

Title = sender.Text + "#" + _PageNum.ToString()

});

MemoText.Text = "";

};

listBox1.MouseDoubleClick += (s, e) =>

{

if (listBox1.IndexFromPoint(new Point(e.X, e.Y)) == -1) return;

if ((ModifierKeys & Keys.Control) == Keys.Control)

{

listBox1.Items.RemoveAt(listBox1.SelectedIndex);

}

else

{

dynamic items = listBox1.SelectedItem;

int.TryParse(items.Page, out int result);

_PageNum = result;

RenderDocument();

}

};

}

private void HeaderEventAttach()

{

NextButton.Click += (s, e) =>

{

if (_PageNum > _Document.PageCount - 1) return;

_PageNum++;

RenderDocument();

hScrollBar1.Value = _PageNum;

};

PrevButton.Click += (s, e) =>

{

if (_PageNum <= 0) return;

_PageNum--;

RenderDocument();

hScrollBar1.Value = _PageNum;

};

PageNumText.KeyDown += (s, e) =>

{

if (e.KeyCode == Keys.Enter)

{

var sender = (TextBox)s;

int.TryParse(sender.Text, out int result);

_PageNum = result;

RenderDocument();

}

if (e.KeyCode == Keys.Right)

{

NextButton.PerformClick();

RenderDocument();

}

if (e.KeyCode == Keys.Left)

{

PrevButton.PerformClick();

RenderDocument();

}

};

}

private void RenderDocument()

{

pictureBox1.Image = _Document.Render(_PageNum - 1, _PageW, _PageH, DeviceDpi, DeviceDpi, false);

PageNumText.Text = Convert.ToString(_PageNum);

}

private int PointToPixel(float point)

{

return (int)(DeviceDpi * point) / 72;

}