画面上のQRコードをデコードするCsharpのフォームアプリを作る

下記、記事を発展させて、画面上に表示されたＱＲコードを、読みこむフォームを作る

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QRCodeEncoderDecoderLibraryを用いてQRコードをデコードする（読み込む）Csharpの単体アプリを作る
https://qiita.com/santarou6/items/7b3a449f7f794639f252

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qr_decode_frm

//c:\Windows\Microsoft.NET\Framework\v4.0.30319\csc.exe /reference:QRCodeEncoderDecoderLibrary.dll /target:winexe qr_decode_frm.cs

using System;
using System.Windows.Forms;
using System.Drawing;
using System.Drawing.Imaging;
using QRCodeEncoderDecoderLibrary;

namespace qr_decode_frm
{
public class Form1 : Form
{

	public Button button1;

	public Form1()
	{
	this.TransparencyKey = this.BackColor;
	button1 = new Button();
	button1.Size = new Size(40, 40);
	button1.Location = new Point(0, 0);
	button1.Text = "★";
	this.Controls.Add(button1);
	button1.Click += new EventHandler(button1_Click);
	}
	
	private void button1_Click(object sender, EventArgs e)
	{
	
	try{
	
	Rectangle rc = this.ClientRectangle;
	Point p = this.PointToScreen(new Point(0, 0));
	double rt = 1.5;  //96dpi_rt=1, 144dpi_rt=1.5
	p.X = (int)(p.X * rt);
	p.Y = (int)(p.Y * rt);
	rc.Width = (int)(rc.Width * rt);
	rc.Height = (int)(rc.Height * rt);
	Bitmap bmp = new Bitmap(rc.Width, rc.Height, PixelFormat.Format32bppArgb);
	var g = Graphics.FromImage(bmp);
	g.CopyFromScreen(p.X, p.Y, 0, 0,rc.Size, CopyPixelOperation.SourceCopy);
	
	QRDecoder   QRCodeDecoder;
	Bitmap      QRCodeInputImage;
	
	QRCodeDecoder = new QRDecoder();
	QRCodeInputImage = bmp;
	byte[][] DataByteArray = QRCodeDecoder.ImageDecoder(QRCodeInputImage);
	
	//string Result = System.Text.Encoding.GetEncoding(932).GetString(DataByteArray[0]);
	string Result = System.Text.Encoding.UTF8.GetString(DataByteArray[0]);
	//string Result = System.Text.Encoding.GetEncoding(51932).GetString(DataByteArray[0]);
	
	MessageBox.Show(Result);
	//Clipboard.SetDataObject(Result,true,20,500);
	
	}
	catch(Exception ex){
		MessageBox.Show("読み取りエラー\n\n"+ex);
	}
	
	}

	[STAThread]
	static void Main()
	{
	Application.EnableVisualStyles();
	Application.Run(new Form1());
	}

}
}

結果