OpenTween.HashtagManage.OK_Button_Click C# (CSharp) Method

        private void OK_Button_Click(object sender, EventArgs e)
        {
            string hash = "";
            foreach (string hs in this.HistoryHashList.SelectedItems)
            {
                hash += hs + " ";
            }
            hash = hash.Trim();
            if (!string.IsNullOrEmpty(hash))
            {
                this.AddHashToHistory(hash, true);
                this._isPermanent = this.CheckPermanent.Checked;
            }
            else
            {
                //使用ハッシュが未選択ならば、固定オプション外す
                this._isPermanent = false;
            }
            this._isHead = this.RadioHead.Checked;
            this._useHash = hash;

            this.DialogResult = DialogResult.OK;
            this.Close();
        }