关闭包含特定字符串的进程

我需要关闭一个包含单词"SoundCloud"的进程我尝试了这个，但不会工作，它确实显示消息框的全名，但不会关闭应用程序的错误system.indexoutofRangeException

 private void getprocess()
    {
        StringBuilder sb = new StringBuilder();
        richTextBox1.Clear();
        int i = 1;
        foreach (Process p in Process.GetProcesses("."))
        {
            try
            {
                if (p.MainWindowTitle.Length > 0)
                {
                    if (p.MainWindowTitle.Contains("SoundCloud"))
                    {
                        timer1.Stop();
                        timer1.Enabled = false;
                        MessageBox.Show("Close "+p.MainWindowTitle.ToString());
                        Process[] proc =      Process.GetProcessesByName(p.MainWindowTitle.ToString());
                        proc[0].Kill();
                    }
                    richTextBox1.AppendText("'n"+i.ToString()+" ). " + p.MainWindowTitle.ToString());
                    i++;
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }
        }