How does C # implement a thread pause, waiting for the user to enter text and continue to run?

using system;using system.text;using system.windows.forms;using            System.threading;namespace windowsapplication1{public partial class Form1:form {public Form1 () {        InitializeComponent ();            } private void Button1_Click (object sender, EventArgs e) {thread th = new Thread (yourthread); Th.        Start (); The private void textBox1_TextChanged (object sender, EventArgs e) {if (TextBox1.Text.Length >=                      4) {detailcollectedevent.set ();        When TextBox1 text exceeds 4 bits, send a notification}} AutoResetEvent detailcollectedevent = new AutoResetEvent (false);            void Yourthread () {MessageBox.Show ("input bank account details into the textbox");                      Detailcollectedevent.waitone ();        Wait for notification MessageBox.Show ("We'll keep the Secret."); }    }}

How does C # implement a thread pause, waiting for the user to enter text and continue to run?