MainForm.cs

using PaddleOCRSharp;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Windows.Forms;
using static System.Windows.Forms.VisualStyles.VisualStyleElement.Window;

namespace OcrHelper
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }
        [DllImport("user32.dll")]
        public static extern bool ReleaseCapture();
        [DllImport("user32.dll")]
        public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);
        public const int WM_SYSCOMMAND = 0x0112;
        public const int SC_MOVE = 0xF010;
        public const int HTCAPTION = 0x0002;

        [DllImport("user32", EntryPoint = "SetWindowPos")]
        public static extern bool SetWindowPos(IntPtr hWnd, IntPtr hWndlnsertAfter, int X, int Y, int cx, int cy, int flags);

        OCRStructureResult ocrResult = new OCRStructureResult();
        PaddleOCREngine ocrEngine;
        Rectangle rectangle = Screen.PrimaryScreen.Bounds;
        string resultOld = "";
        private void MainForm_Load(object sender, EventArgs e)
        {
            this.BackColor = Color.Red;
            this.TransparencyKey = Color.Red;
            SetWindowPos(this.Handle, new IntPtr(-1),this.Left,this.Top,this.Width,this.Height,1|2);

            OCRModelConfig config = new OCRModelConfig();
            string root = System.IO.Path.GetDirectoryName(System.Windows.Forms.Application.ExecutablePath);

            string modelPathroot = root + @"\inference";
            config.det_infer = modelPathroot + @"\ch_PP-OCRv3_det_infer";
            config.cls_infer = modelPathroot + @"\ch_ppocr_mobile_v2.0_cls_infer";
            config.rec_infer = modelPathroot + @"\ch_PP-OCRv3_rec_infer";
            config.keys = modelPathroot + @"\ppocr_keys.txt";
            ocrEngine = new PaddleOCREngine(config, new OCRParameter());
            new Thread(() =>
            {
                while (true)
                {
                    StartOcr(true);
                    Thread.Sleep(100);
                }

            })
            { IsBackground = true }.Start();
        }

        private void MainForm_MouseDown(object sender, MouseEventArgs e)
        {
            ReleaseCapture();
            SendMessage(this.Handle, WM_SYSCOMMAND, SC_MOVE + HTCAPTION, 0);
        }
        public void StartOcr(bool auto = false)
        {
            if (!checkBox_Auto.Checked && auto) { return; }
            Image image = new Bitmap(panel_Image.Width, panel_Image.Height);
            Graphics graph = Graphics.FromImage(image);
            graph.CopyFromScreen(new Point(this.Left, this.Top + (this.Height - this.ClientSize.Height)), new Point(0, 0), new Size(panel_Image.Width, panel_Image.Height - (this.Height - this.ClientSize.Height)));
            MemoryStream ms = new MemoryStream();
            image.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
            ocrResult = ocrEngine.DetectStructure(image);
            List<TextBlock> textBlocks = ocrResult.TextBlocks;
            string result = "";
            for (int i = 0; i < textBlocks.Count; i++)
            {
                result += textBlocks[i].Text + "\r\n";

            }
            if (checkBox_Append.Checked)
            {
                if (resultOld != result)
                {
                    this.BeginInvoke(new Action(() =>
                   {
                       richTextBox_Result.Text += result;
                       if (!richTextBox_Result.Focused)
                       {
                           richTextBox_Result.SelectionStart = richTextBox_Result.Text.Length;
                           richTextBox_Result.ScrollToCaret();
                       }
                   }));
                    resultOld = result;
                }
            }
            else
            {
                this.BeginInvoke(new Action(() =>
                {
                    richTextBox_Result.Text = result;
                }));
            }


        }

        private void button_StartOcr_Click(object sender, EventArgs e)
        {
            StartOcr(false);
        }

        private void checkBox_Auto_CheckedChanged(object sender, EventArgs e)
        {
            if (checkBox_Auto.Checked) { button_StartOcr.Enabled = false; }
            else {
                button_StartOcr.Enabled = true;
            }
        }

        private void linkLabel_Source_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            Process.Start(new ProcessStartInfo { UseShellExecute = true, FileName = "https://github.com/xksoft/OcrHelper" });

        }
    }
}