private void btnAddRow_Click(object sender, EventArgs e)
{
MyTextBox.SelectionChanged -= richTextBox_SelectionChanged;
var tabTemp = tabControlMain.SelectedTab;
var index = MyTextBox.GetFirstCharIndexOfCurrentLine();
var insertText = GetSelectedTabsString();
if (!MyTextDataAdapter.HasCrLf)
{
insertText = insertText + "\r\n";
}
var nextIndex = index + insertText.Length;
MyTextBox.Text = MyTextBox.Text.Insert(index, insertText);
MyTextBox.SelectionStart = nextIndex;
tabControlMain.SelectedTab = tabTemp;
MyTextBox.SelectionChanged += richTextBox_SelectionChanged;
MyTextBox.Focus();
}