kmpdfkit_demo/compdfkit_demo_windows/compdfkit/compdfkit-tools/Helper/CommonHelper.cs

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace compdfkit_tools.Helper
{
    public static class CommonHelper
    {
        /// <summary>
        /// Returns the file size based on the specified file path, with the smallest unit being bytes (B).
        /// </summary>
        /// <param name="filePath">The path to the file.</param>
        /// <returns>
        /// The calculated file size, with units in bytes (B), kilobytes (KB), megabytes (MB), or gigabytes (GB).
        /// </returns>
        public static string GetFileSize(string filePath)
        {
            FileInfo fileInfo = null;
            try
            {
                fileInfo = new FileInfo(filePath);
            }
            catch
            {
                return "0B";
            }
            if (fileInfo != null && fileInfo.Exists)
            {
                double fileSize = fileInfo.Length;
                if (fileSize > 1024)
                {
                    fileSize = Math.Round(fileSize / 1024, 2);
                    if (fileSize > 1024)
                    {
                        fileSize = Math.Round(fileSize / 1024, 2);
                        if (fileSize > 1024)
                        {
                            fileSize = Math.Round(fileSize / 1024, 2);
                            return fileSize + " GB";
                        }
                        else
                        {
                            return fileSize + " MB";
                        }
                    }
                    else
                    {
                        return fileSize + " KB";
                    }
                }
                else
                {
                    return fileSize + " B";
                }
            }
            return "0B";
        }
        public static string GetFilePathOrEmpty()
        {
            string selectedFilePath = string.Empty;
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.Filter = "PDF files (*.pdf)|*.pdf";

            if (openFileDialog.ShowDialog() == true)
            {
                selectedFilePath = openFileDialog.FileName;
            }
            return selectedFilePath;
        }
    }
}