how to show checkbox list items in one line using C#

I have written a code for the same.

private void btnColumnWrite_Click(object sender, EventArgs e)
{
string s = "";
for (int i = 0; i < checkedListBox1.Items.Count; i++)
{
if(checkedListBox1.GetItemChecked(i))
{
s += checkedListBox1.Items[i] +",";
}
}
StreamWriter SwriteData = new StreamWriter(@"C:\Users\user\Desktop\ReportTmplate\Test.txt");
SwriteData.WriteLine("(" + s + ")");
SwriteData.Close();
}