无法从双精度转换为字符串c#

我已经试过了，但它给了我一个错误“无法从double转换为string”，我想将变量

ProgressBarMegabyte

更改为下面的等式

ProgressBarMegabyte = (Int32.Parse(ProgressBarMegabyte) + Double.Parse(Convert.ToString(ProgressedMegabytes)));

我的全部代码：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Xml;

namespace SoftwareStoreClientDownloader
{
    public partial class OfflineInstaller : Form
    {
        public OfflineInstaller()
        {
            InitializeComponent();
            FormClosing += OfflineInstaller_FormClosing;
        }

        private void OfflineInstaller_FormClosing(object sender, FormClosingEventArgs e)
        {
            File.WriteAllText("C:\\Closed.txt", "true");
        }

        private void OfflineInstaller_Load(object sender, EventArgs e)
        {
            if (!Directory.Exists("C:\\Program Files\\SoftwareStoreOffline"))
            {
                Directory.CreateDirectory("C:\\Program Files\\SoftwareStoreOffline");
            }
        }

        private void BrowseButton_Click(object sender, EventArgs e)
        {
            SaveFileDialog s = new SaveFileDialog();
            s.DefaultExt = "iso";
            s.AddExtension = false;
            s.CheckPathExists = true;
            s.ShowDialog();
            try
            {
                BrowseFileTextBox.Text = s.FileName;
            }
            catch (Exception dew)
            {

            }
        }

        private async void button1_Click(object sender, EventArgs e)
        {
            var i = 2;
            button1.Enabled = false;
            button1.Text = "Initializing";
            await Initialize();
            button1.Text = "Downloading";
            TotalProgressBar.Maximum = Int32.Parse(Parts);
            if (Int32.Parse(Parts) > 99)
            {
                await Download(
                    "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline" + Database +
                    "/master/SoftwareStore" + Version + "Setup-Files.part001.exe",
                    MainDirectory + "\\" + "Setup-Files.part001.exe");
            }
            else
            {
                await Download(
                    "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline" + Database +
                    "/master/SoftwareStore" + Version + "Setup-Files.part01.exe",
                    MainDirectory + "\\" + "Setup-Files.part01.exe");
            }
            var TotalProgressBytes = ((Int32.Parse(TotalBytes) / 1024d / 1024d) * Int32.Parse(Parts));
            var TotalMegabytes = TotalProgressBytes;
            var ProgressedMegabytes = (Int32.Parse(TotalBytes) / 1024d / 1024d);
            var ProgressBarMegabyte = string.Empty;
            ProgressBarMegabyte = ProgressedMegabytes.ToString();
            while (i < Int32.Parse(Parts) + 1)
            {
                if (Int32.Parse(Parts) < 100)
                {
                    if (i < 10)
                    {
                        await Download(
                            "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline" + Database +
                            "/master/SoftwareStore" + Version + "Setup-Files.part0" + i + ".rar",
                            MainDirectory + "\\" + "Setup-Files.part0" + i + ".rar");
                    }
                    else
                    {
                        await Download(
                            "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline" + Database +
                            "/master/SoftwareStore" + Version + "Setup-Files.part" + i + ".rar",
                            MainDirectory + "\\" + "Setup-Files.part" + i + ".rar");
                    }
                }
                else if (Int32.Parse(Parts) > 99)
                {
                    if (i < 10 && i < 100)
                    {
                        await Download(
                            "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline" + Database +
                            "/master/SoftwareStore" + Version + "Setup-Files.part00" + i + ".rar",
                            MainDirectory + "\\" + "Setup-Files.part00" + i + ".rar");
                    }
                    else if(i > 10 && i < 100)
                    {
                        await Download(
                            "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline" + Database +
                            "/master/SoftwareStore" + Version + "Setup-Files.part0" + i + ".rar",
                            MainDirectory + "\\" + "Setup-Files.part0" + i + ".rar");
                    }
                    else if (i > 99)
                    {
                        await Download(
                            "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline" + Database +
                            "/master/SoftwareStore" + Version + "Setup-Files.part" + i + ".rar",
                            MainDirectory + "\\" + "Setup-Files.part" + i + ".rar");
                    }
                }
                else if (Int32.Parse(Parts) < 10)
                {
                    await Download(
                        "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline" + Database +
                        "/master/SoftwareStore" + Version + "Setup-Files.part" + i + ".rar",
                        MainDirectory + "\\" + "Setup-Files.part" + i + ".rar");
                }

                DownloadProgressLabel.Text = "Status: (" + i + "/" + Parts + ")";
                if (i < TotalProgressBar.Maximum)
                {
                    TotalProgressBar.Value = i;
                }

                if (first == false)
                {
                    TotalProgressLabel.Text = "(" + ProgressBarMegabyte + " MB / " + TotalMegabytes + " MB)";
                    first = true;
                }
                else
                {
                    TotalProgressLabel.Text = "(" + ProgressBarMegabyte + " MB / " + TotalMegabytes + " MB)";
                }

                int Equation = Convert.ToInt32(Int32.Parse(ProgressBarMegabyte) +
                                       Double.Parse(Convert.ToString(ProgressedMegabytes)));
                ProgressBarMegabyte = Equation.ToString();

                i++;
            }

            if (Int32.Parse(Parts) > 99)
            {
                await Task.Factory.StartNew(() =>
                {
                    Process.Start(@"C:\Program Files\SoftwareStoreOffline\Setup-Files.part001.exe").WaitForExit();
                });
            }
            else if (Int32.Parse(Parts) < 100)
            {
                await Task.Factory.StartNew(() =>
                {
                    Process.Start(@"C:\Program Files\SoftwareStoreOffline\Setup-Files.part01.exe");
                });
            }
            else if(Int32.Parse(Parts) < 10)
            {
                await Task.Factory.StartNew(() =>
                {
                    Process.Start(@"C:\Program Files\SoftwareStoreOffline\Setup-Files.part1.exe");
                });
            }
        }

        private bool first = false;
        private string MainDirectory = "C:\\Program Files\\SoftwareStoreOffline";
        private string TotalBytes = string.Empty;
        private async Task Download(string link, string Filename)
        {
            using (var client = new WebClient())
            {
                client.DownloadProgressChanged += Client_DownloadProgressChanged;
                client.DownloadFileCompleted += Client_DownloadFileCompleted;
                client.DownloadFileAsync(new Uri(link), Filename);
                while (client.IsBusy)
                {
                    await Task.Delay(10);
                }
            }
        }

        private void Client_DownloadFileCompleted(object sender, AsyncCompletedEventArgs e)
        {
            if (e.Cancelled)
            {

            }
            else if (e.Error != null)
            {

            }
            else
            {

            }
        }

        private void Client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
        {
            TotalBytes = e.TotalBytesToReceive.ToString();
            DownloadProgressBar.Value = e.ProgressPercentage;
        }

        private string Parts = string.Empty;
        private string Database = string.Empty;
        private string Version = string.Empty;
        private async Task Initialize()
        {
            try
            {
                await Download(
                    "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreClientDownloader/master/OfflineDatabaseNumber.txt",
                    MainDirectory + "\\OfflineDatabaseNumber.txt");
                await Download(
                    "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreClientDownloader/master/OfflineParts.txt",
                    MainDirectory + "\\OfflineParts.txt");
                await Download(
                    "https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreClientDownloader/master/OfflineVersion.txt",
                    MainDirectory + "\\OfflineVersion.txt");
                Parts = File.ReadLines(MainDirectory + "\\OfflineParts.txt").First();
                Database = File.ReadLines(MainDirectory + "\\OfflineDatabaseNumber.txt").First();
                Version = File.ReadLines(MainDirectory + "\\OfflineVersion.txt").First();
            }
            catch (Exception dew)
            {
                Console.WriteLine(dew);
                throw;
            }
        }
    }
}

使用系统；
使用System.Collections.Generic；
使用系统组件模型；
使用系统数据；
使用系统诊断；
使用系统图；
使用System.IO；
使用System.Linq；
Net系统；
使用系统文本；
使用System.Threading.Tasks；
使用System.Windows.Forms；
使用System.Xml；
命名空间SoftwareStoreClientDownloader
{
公共部分类脱机安装程序：表单
{
公共脱机安装程序（）
{
初始化组件（）；
FormClosing+=离线安装程序\u FormClosing；
}
private void OfflineInstaller_FormClosing（对象发送方，FormClosingEventArgs e）
{
File.writealText（“C:\\Closed.txt”，“true”）；
}
private void OfflineInstaller_加载（对象发送方，事件参数e）
{
如果（！Directory.Exists（“C:\\Program Files\\SoftwareStoreOffline”））
{
目录.CreateDirectory（“C:\\Program Files\\SoftwareStoreOffline”）；
}
}
私有无效浏览按钮单击（对象发送者，事件参数e）
{
SaveFileDialog s=新建SaveFileDialog（）；
s、 DefaultExt=“iso”；
s、 AddExtension=false；
s、 CheckPathExists=true；
s、 ShowDialog（）；
尝试
{
BrowseFileTextBox.Text=s.FileName；
}
捕获（例外情况）
{
}
}
私有异步无效按钮1\u单击（对象发送方，事件参数e）
{
var i=2；
按钮1.启用=错误；
按钮1.Text=“初始化”；
等待初始化（）；
按钮1.Text=“下载”；
TotalProgressBar.max=Int32.Parse（部分）；
if（Int32.Parse（Parts）>99）
{
等待下载(
"https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline“+数据库+
“/master/SoftwareStore”+Version+“安装文件.part001.exe”，
MainDirectory+“\\”+“安装文件.part001.exe”）；
}
其他的
{
等待下载(
"https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline“+数据库+
“/master/SoftwareStore”+Version+“安装文件.part01.exe”，
MainDirectory+“\\”+“安装文件.part01.exe”）；
}
var TotalProgressBytes=（（Int32.Parse（TotalBytes）/1024d/1024d）*Int32.Parse（Parts））；
var TotalMegabytes=TotalProgressBytes；
var ProgressedMegabytes=（Int32.Parse（TotalBytes）/1024d/1024d）；
var ProgressBarMegabyte=string.Empty；
ProgressBarMegabyte=ProgressedMegabytes.ToString（）；
而（i99）
{
如果（i<10&&i<100）
{
等待下载(
"https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline“+数据库+
“/master/SoftwareStore”+Version+“安装文件.part00”+i+“.rar”，
MainDirectory+“\\”+“安装文件.part00”+i+“.rar”）；
}
否则，如果（i>10&&i<100）
{
等待下载(
"https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline“+数据库+
“/master/SoftwareStore”+Version+“安装文件.part0”+i+“.rar”，
MainDirectory+“\\”+“安装文件.part0”+i+“.rar”）；
}
否则，如果（i>99）
{
等待下载(
"https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline“+数据库+
“/master/SoftwareStore”+Version+”安装文件。部分“+i+”.rar”，
MainDirectory+“\\”+“安装文件.part“+i+”.rar”）；
}
}
else if（Int32.Parse（Parts）<10）
{
等待下载(
"https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline“+数据库+
“/master/SoftwareStore”+Version+”安装文件。部分“+i+”.rar”，
MainDirectory+“\\”+“安装文件.part“+i+”.rar”）；
}
DownloadProgressLabel.Text=“状态：（“+i+”/“+Parts+”）”；
如果（isting = int + double

double ProgressedMegabytes = 1.5;
string ProgressBarMegabyte = "83345603 .....................";

ProgressBarMegabyte = (Int32.Parse(ProgressBarMegabyte.TrimEnd('.')) + ProgressedMegabytes).ToString();

Console.WriteLine(ProgressBarMegabyte); // 83345604.5

int Equation = Convert.ToInt32(Int32.Parse(ProgressBarMegabyte)
    + Double.Parse(Convert.ToString(ProgressedMegabytes)));                
ProgressBarMegabyte = Equation.ToString();

private async void button1_Click(object sender, EventArgs e)
{
    var i = 2;
    await Initialize();

    var name = Parts > 99 ? "part001" : "part01";
    await Download($"https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline{Database}/master/SoftwareStore{Version}Setup-Files.{name}.exe", $"{MainDirectory}\\Setup-Files.{name}.exe");

    var format = new string('0', Parts.ToString().Length)
    while (i < Parts + 1)
    {
        await Download($"https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreOffline{Database}/master/SoftwareStore{Version}Setup-Files.part{i.ToString(format)}.rar", $"{MainDirectory}\\Setup-Files.{i.ToString(format)}.rar");
        i++;
    }

    await Task.Factory.StartNew(() =>
    {
        Process.Start($@"C:\Program Files\SoftwareStoreOffline\Setup-Files.part{1.ToString(format)}.exe").WaitForExit();
    });

}

private string MainDirectory = "C:\\Program Files\\SoftwareStoreOffline";
private async Task Download(string link, string Filename)
{
    using (var client = new WebClient())
    {
        await client.DownloadFileTaskAsync(link, Filename);
    }
}

private int Parts;
private string Database = string.Empty;
private string Version = string.Empty;
private async Task Initialize()
{
    try
    {
        await Download("https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreClientDownloader/master/OfflineDatabaseNumber.txt", MainDirectory + "\\OfflineDatabaseNumber.txt");
        await Download("https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreClientDownloader/master/OfflineParts.txt", MainDirectory + "\\OfflineParts.txt");
        await Download("https://raw.githubusercontent.com/CNTowerGUN/SoftwareStoreClientDownloader/master/OfflineVersion.txt", MainDirectory + "\\OfflineVersion.txt");
        Parts = int.Parse(File.ReadLines(MainDirectory + "\\OfflineParts.txt").First());
        Database = File.ReadLines(MainDirectory + "\\OfflineDatabaseNumber.txt").First();
        Version = File.ReadLines(MainDirectory + "\\OfflineVersion.txt").First();
    }
    catch (Exception dew)
    {
        Console.WriteLine(dew);
        throw;
    }
}