Use threads in Asp.net

Make a task class, know how long the task has been executed from time to time on the client (and the refresh time is 1 second), and give the execution time after the task is successfully completed, the error time is displayed when the task fails.

Front-end

<Form ID = "form1" method = "Post" runat = "server">

<Asp: Label id = "lab_state" runat = "server"> </ASP: Label> <br>

<Asp: button id = "btn_startwork" runat = "server" text = "running a long task"> </ASP: button>

</Form>

Background

First, some class declarations:

Protected system. Web. UI. webcontrols. Button btn_startwork;

Protected system. Web. UI. webcontrols. Label lab_state;

// The first two are self-generated by vs.net.

Protected work W;

Enter the following in page_load:Code:

If (session ["work"] = NULL)

{

W = new work ();

Session ["work"] = W;

}

Else

{

W = (work) session ["work"];

}

Switch (W. State)

{

Case 0:

{

This. lab_state.text = "task not started ";

Break;

}

Case 1:

{

This. lab_state.text = "task performed" + (timespan) (datetime. Now-w.StartTime). totalseconds + "seconds ";

This. btn_startwork.enabled = false;

Page. registerstartupscript ("", "<SCRIPT> window. setTimeout ('location. href = location. href ', 1000); </SCRIPT> ");

// Constantly refresh this page and update the task status at any time

Break;

}

Case 2:

{

This. lab_state.text = "the task is finished and all operations are successfully performed, with" + (timespan) (W. FinishTime-w.StartTime). totalseconds + "seconds ";

This. btn_startwork.enabled = true;

Break;

}

Case 3:

{

This. lab_state.text = "task ended, with an error in" + (timespan) (W. ErrorTime-w.StartTime). totalseconds + "seconds leading to task failure ";

This. btn_startwork.enabled = true;

Break;

}

}

Enter the following code in the button-click event:

If (W. State! = 1)

{

This. btn_startwork.enabled = false;

W. runwork ();

Page. registerstartupscript ("", "<SCRIPT> location. href = location. href; </SCRIPT> ");

// Refresh the page immediately

}

Create a task class with the following code:

Public class work

{

Public int state = 0; // 0-not started, 1-running, 2-successful, 3-failed

Public datetime starttime;

Public datetime finishtime;

Public datetime errortime;

Public void runwork ()

{

Lock (this) // ensure that the critical section is occupied by a thread

{

If (State! = 1)

{

State = 1;

Starttime = datetime. now;

System. Threading. Thread thread = new system. Threading. Thread (new system. Threading. threadstart (dowork ));

Thread. Start ();

}

}

}

Private void dowork ()

{

Try

{

Sqlconnection conn = new sqlconnection (system. configuration. configurationsettings. deleettings ["conn"]);

Sqlcommand cmd = new sqlcommand ("insert into test (test) values ('test')", Conn );

Conn. open ();

For (INT I = 0; I <5000; I ++) cmd. executenonquery ();

Conn. Close ();

// Execute a time-consuming database operation with the above Code

State = 2;

}

Catch

{

Errortime = datetime. now;

State = 3;

}

Finally

{

Finishtime = datetime. now;

}

}

}

}

Run this page and you will see the time when the feedback task is executed every second. The total time of the task is given after the end. (If a task error occurs, the error time is also displayed)