title: How to add timespan values in list
body: <p>In the below code i will get a list of time span values. I need to add all the time span values and that value has to be stored in string.How to achieve this i tried a lot but I can't find answer for this.
  Thanks in Advance.</p>
  
  <pre><code>  List&lt;TimeSpan&gt; objList = new List&lt;TimeSpan&gt;();
          string  totalIntervalTime = string.Empty;
       private void Resume_Click(object sender, EventArgs e)
              {
                  if (!string.IsNullOrEmpty(textBox2.Text))
                  {
                      textBox3.Text = DateTime.Now.ToLongTimeString();
                      //objPausetmr.Tick += new EventHandler(objPausetmr_Tick);
                      //objPausetmr.Stop();
                      tmrObj.Start();
                      DateTime pausetime = Convert.ToDateTime(textBox2.Text);
                      DateTime startTime = Convert.ToDateTime(textBox3.Text);
                      TimeSpan difference = pausetime - startTime;
                      string intervalDifference = difference.ToString();
                      richTextBox1.Text = intervalDifference;
  
                      TimeSpan tltTime = TimeSpan.Zero;
                      objList.Add(difference);
                      foreach (TimeSpan tmVal in objList)
                      {
                          tltTime.Add(tmVal);
                      }
                      totalIntervalTime = tltTime.ToString();
  
                      //MessageBox.Show(interval_Time.ToString());
                  }
                  else
                  {
                      MessageBox.Show("Please set the Pause time");
                  }
              }
  </code></pre>