Controlling a Windows Service

Add a new Windows Application project to the solution. Name the project StepByStep6_5.

Rename the default Form1.cs file to WindowsServiceController.cs. Access the properties window for this form and change the Name property to WindowsServiceController and the Text property to Windows Service Controller. Switch to the code view and change all instances of Form1 to WindowsServiceController.

Add a ListBox control (lbServiceList), a TextBox control (txtStatus), and 4 Button controls (btnStart, btnStop, btnPauseContinue, and btnRefresh) on the form. Arrange the controls as shown in Figure.

Add a reference to the System.ServiceProcess.dll to the project. Add the following using directive to the code:

using System.ServiceProcess;

Double-click on an empty area on the form to attach an event handler with its Load event. Add the following code to its event handler:

private void WindowsServiceController_Load

             (object sender, System.EventArgs e)

{

    PopulateServiceList();

}



// Get the list of installed services

protected void PopulateServiceList()

{

    // Populate services in the list box

    lbServiceList.DataSource =

        ServiceController.GetServices();

    // Display friendly name

    lbServiceList.DisplayMember = "DisplayName";

}

Double-click on the ListBox to attach an event handler with its SelectedIndexChanged event. Add the following code to its event handler:

private void lbServiceList_SelectedIndexChanged

             (object sender, System.EventArgs e)

{

    // Retrieve the selected service

    ServiceController service =

       (ServiceController) lbServiceList.SelectedItem;

    // and get status for it

    GetServiceStatus(service);

}



// Find the latest service status

protected void GetServiceStatus(ServiceController sc)

{

    // Get the service status

    ServiceControllerStatus status = sc.Status;

    // Enable all buttons

    btnStart.Enabled = btnStop.Enabled =

        btnPauseContinue.Enabled = true;

    // Disable the pause button if it does

    // not support pause and continue messages

    if (!sc.CanPauseAndContinue)

        btnPauseContinue.Enabled = false;

    // Disable the stop button if it does

    // not support stop message

    if (!sc.CanStop)

        btnStop.Enabled = false;

    // Enable and disable buttons based on

    // service status, also display the text

    // for the status

    switch (status)

    {

        case ServiceControllerStatus.ContinuePending:

            txtStatus.Text = "Continue Pending";

            btnPauseContinue.Enabled = false;

            break;

        case ServiceControllerStatus.Paused:

            txtStatus.Text = "Paused";

            btnPauseContinue.Text = "Continue";

            btnStart.Enabled = false;

            break;

        case ServiceControllerStatus.PausePending:

            txtStatus.Text = "Pause Pending";

            btnPauseContinue.Enabled = false;

            btnStart.Enabled = false;

            break;

        case ServiceControllerStatus.Running:

            txtStatus.Text = "Running";

            btnPauseContinue.Text = "Pause";

            btnStart.Enabled = false;

            break;

        case ServiceControllerStatus.StartPending:

            txtStatus.Text = "Start Pending";

            btnStart.Enabled = false;

            break;

        case ServiceControllerStatus.Stopped:

            txtStatus.Text = "Stopped";

            btnStop.Enabled = false;

            break;

        case ServiceControllerStatus.StopPending:

            txtStatus.Text = "Stop Pending";

            btnStop.Enabled = false;

            break;

        default:

            txtStatus.Text = "Unknown Status";

            break;

    }

}

Add the following event handler and attach it to the Click event of btnStart, btnStop, and btnPauseContinue buttons.

// Common event handler for the Click event on

// start, stop, and pause/continue buttons

private void btnControl_Click

     (object sender, System.EventArgs e)

{

    // It might take time, so change the

    // cursor to a wait cursor

    Cursor.Current = Cursors.WaitCursor;

    // Retrieve the selected service

    ServiceController service =

        (ServiceController)

        lbServiceList.SelectedItem;

    if (sender == this.btnStart)

    {

        // Start the service and wait till

        // the status is Running

        service.Start();

        service.WaitForStatus

            (ServiceControllerStatus.Running);

    }

    else if (sender == this.btnStop)

    {

        // Stop the service and wait till

        // the status is Stopped

        service.Stop();

        service.WaitForStatus

            (ServiceControllerStatus.Stopped);

    }

    else if (sender == this.btnPauseContinue)

    {

        if (btnPauseContinue.Text == "Pause")

        {

            // Pause the service and wait till

            // the status is Paused

            service.Pause();

            service.WaitForStatus

                (ServiceControllerStatus.Paused);

        }

        else

        {

            // Resume the service and wait till

            // the status is Running

            service.Continue();

            service.WaitForStatus

                (ServiceControllerStatus.Running);

        }

    }

    // Refresh the list

    int intIndex = lbServiceList.SelectedIndex;

    PopulateServiceList();

    lbServiceList.SelectedIndex = intIndex;

    // Change the cursor back to normal

    Cursor.Current = Cursors.Default;

}

Add the following event handler to the Click event of the btnRefresh control:

private void btnRefresh_Click

        (object sender, System.EventArgs e)

{

    // Refresh the list

    int intIndex = lbServiceList.SelectedIndex;

    PopulateServiceList();

    lbServiceList.SelectedIndex = intIndex;

}

Build the StepByStep6_5 project. Set the project as the startup object. Run the project. You will see a window displaying a list of installed services, as shown in Figure.

Scroll through the list of services. Select OrderService. Pause the service and then continue. Stop the service and then start. As you do this, also create new XML files in the c:\orders directory. You should find that the files are not processed when the OrderService is paused or stopped.

Open the Application EventLog. You'll see that each time you start, pause, continue, or stop the OrderService service, an entry in the Application event log is written because you set the AutoLog property for the Windows service to true.

Click on the Refresh button to update the list of installed services with any newly installed or uninstalled services.