如何在编辑后关闭文本文件

我在form application中有一个文本文件installer_input.txt和checkedListBox2。如果我在checkesListBox2中有一些变化，我想编辑文本文件。我有两部分代码，我知道这很长，但我需要一些帮助:

 private void checkedListBox2_SelectedIndexChanged(object sender, EventArgs e)
        {
            string path = AppDomain.CurrentDomain.BaseDirectory.ToString();
            var lin = (path + "config.ini").ToString();
            var lines = File.ReadAllLines(lin);
            string InstallerFile = lines.Where(txt => txt.Contains("IstallerFile="))
                        .Select(txt => txt.Split('=')[1].Replace("'"", "")).FirstOrDefault();
             string pathTemp = @"C:'temp'";
            string[] pathArr = InstallerFile.Split('''');
            string[] fileArr = pathArr.Last().Split('''');
            string fileArr1 = String.Join(" ", fileArr);

            string installerfilename = string.Format("{0}{1}", pathTemp, fileArr1);
            IEnumerable<string> inilines = File.ReadAllLines(installerfilename).AsEnumerable();
            bool IsChecked = checkedListBox2.CheckedItems.Contains(checkedListBox2.SelectedItem);
 else if (fileArr1.Equals("installer_input.txt"))
            {
                if (IsChecked && checkedListBox2.CheckedItems.Count != checkedListBox2.Items.Count)
                    inilines = inilines.Select(line => line == string.Format("#product.{0}", checkedListBox2.SelectedItem)
                                                       ? Regex.Replace(line, string.Format("#product.{0}", checkedListBox2.SelectedItem), string.Format(@"product.{0}", checkedListBox2.SelectedItem))
                                                       : line);
                else if (!IsChecked || checkedListBox2.CheckedItems.Count == checkedListBox2.Items.Count)
                    inilines = inilines.Select(line => (line == string.Format("product.{0}", checkedListBox2.SelectedItem))
                                                       ? Regex.Replace(line, string.Format(@".*product.{0}", checkedListBox2.SelectedItem), string.Format(@"#product.{0}", checkedListBox2.SelectedItem))
                                                       : line);
                if (checkedListBox2.CheckedItems.Count == checkedListBox2.Items.Count)
                    checkBox1.Checked = true;
                else
                    checkBox1.Checked = false;
                string strWrite = string.Join(Environment.NewLine, inilines.ToArray());
                File.WriteAllText(installerfilename, strWrite);
            }
        }

第二个代码是:

private void checkBox1_CheckedChanged_1(object sender, EventArgs e)
        {
            CheckBox cb = sender as CheckBox;
            SetAllItemsChecked(cb.Checked);
            var installerLines = ReadInstallerLines();
            SetAllProductsChecked(installerLines.ToList(), cb.Checked);
            SaveInstaller(installerLines);
        }
        private void SetAllItemsChecked(bool check)
        {
            for (int i = 0; i < this.checkedListBox2.Items.Count; i++)
            {
                this.checkedListBox2.SetItemChecked(i, check);
            }
        }
        private IEnumerable<string> ReadInstallerLines()
        {
            var lin = (path + "config.ini").ToString();
            var lines = File.ReadAllLines(lin);
            string InstallerFile = lines.Where(txt => txt.Contains("IstallerFile="))
                        .Select(txt => txt.Split('=')[1].Replace("'"", "")).FirstOrDefault();
            string pathTemp = @"C:'temp'";
            string[] pathArr = InstallerFile.Split('''');
            string[] fileArr = pathArr.Last().Split('''');
            string fileArr1 = String.Join(" ", fileArr);
            string installerfilename = pathTemp + fileArr1;
            string installertext = File.ReadAllText(installerfilename);
            return File.ReadLines(pathTemp + fileArr1);
        }
        private void SetAllProductsChecked(IList<string> installerLines, bool check)
        {
            for (var i = 0; i < installerLines.Count; i++)
            {
                if (installerLines[i].Contains("product="))
                {
                    installerLines[i] = check
                        ? installerLines[i].Replace("#product", "product")
                        : installerLines[i].Replace("product", "#product");
                }
                if (installerLines[i].Contains("product."))
                {
                    installerLines[i] = check
                        ?installerLines[i].Replace("#product.", "product.")
                         : installerLines[i].Replace("product.", "#product.");
                }
            }
        }
        private void SaveInstaller(IEnumerable<string> installerLines)
        {
            var lin = (path + "config.ini").ToString();
            var lines = File.ReadAllLines(lin);
            string InstallerFile = lines.Where(txt => txt.Contains("IstallerFile="))
                        .Select(txt => txt.Split('=')[1].Replace("'"", "")).FirstOrDefault();
            string pathTemp = @"C:'temp'";
            string[] pathArr = InstallerFile.Split('''');
            string[] fileArr = pathArr.Last().Split('''');
            string fileArr1 = String.Join(" ", fileArr);
            string installerfilename = pathTemp + fileArr1;         
            File.WriteAllLines(installerfilename, installerLines);
        }
    }

首先工作，我可以从列表中检查框，但是当我试图点击checkBox1时，我有下一个错误:The process cannot access the file 'C:'temp'installer_input.txt' because it is used by another process。我怎样才能使程序工作?如何优化我的代码?

EventWaitHandle waitHandle = new EventWaitHandle(true, EventResetMode.AutoReset, "SHARED_BY_ALL_PROCESSES");
waitHandle.WaitOne();
/* process file*/
waitHandle.Set();