How to: Use the HardwareButton Component

You can configure the hardware buttons on a Pocket PC to activate a Form. This example activates an application with the first and fourth hardware buttons, and indicates in the status bar which button was pressed.

To set a hardware button to activate a form

1. Create a Pocket PC Windows application.

2. Create an instance of a HardwareButton.

3. Set the AssociatedControl property to the form.

4. Set the HardwareKey property to an application key defined by the HardwareKeys enumeration.

5. Repeat steps 2 through 4 for additional hardware buttons you want to use.

6. When a hardware button is pressed and released, the form receives both the KeyDown and KeyUp events. You can use either event to determine whether a hardware button was pressed.

Example

This example sets the first and fourth hardware buttons to activate the form. To demonstrate, follow these steps:

1. Run the application.

2. Open another application on the device.

3. Press hardware button 1 or 4 to activate the form of this application. The status bar indicates which hardware button was pressed.

Private Sub ConfigHWButton()
    ' Set KeyPreview to true so that the form  
    ' will receive key events before they  
    ' are passed to the control that has focus.  

    Me.KeyPreview = True

    hwb1 = New HardwareButton()
    hwb4 = New HardwareButton()

    ' Set the AssociatedControl property 
    ' to the current form and configure the 
    ' first and fourth buttons to activate the form. 
    Try
        hwb1.AssociatedControl = Me
        hwb4.AssociatedControl = Me
        hwb1.HardwareKey = HardwareKeys.ApplicationKey1
        hwb4.HardwareKey = HardwareKeys.ApplicationKey4
    Catch exc As Exception
        MessageBox.Show(exc.Message & " Check if the hardware button is " & _
            "physically available on this device.")
    End Try 
End Sub 

Private Overloads Sub OnKeyUp(sender As Object, e As KeyEventArgs) _
    Handles MyBase.KeyUp
    ' When a hardware button is pressed and released, 
    ' this form receives the KeyUp event. The OnKeyUp 
    ' method is used to determine which hardware 
    ' button was pressed, because the event data 
    ' specifies a member of the HardwareKeys enumeration. 
    Select Case CType(e.KeyCode, HardwareKeys)
        Case HardwareKeys.ApplicationKey1
            statusBar1.Text = "Button 1 pressed." 

        Case HardwareKeys.ApplicationKey4
            statusBar1.Text = "Button 4 pressed." 

        Case Else 
    End Select 
End Sub

// Configure hardware buttons 
// 1 and 4 to activate the current form. 
private void HBConfig()
    {
        try 
        {
            hwb1 = new HardwareButton();
            hwb4 = new HardwareButton();
            hwb1.AssociatedControl = this;
            hwb4.AssociatedControl = this;
            hwb1.HardwareKey = HardwareKeys.ApplicationKey1;
            hwb4.HardwareKey = HardwareKeys.ApplicationKey4;
        }
        catch (Exception exc)
        {
            MessageBox.Show(exc.Message + " Check if the hardware " +
                "button is physically available on this device.");
        }
}

// When a hardware button is pressed and released, 
// this form receives the KeyUp event. The OnKeyUp 
// method is used to determine which hardware 
// button was pressed, because the event data 
// specifies a member of the HardwareKeys enumeration. 
private void OnKeyUp(object sender, KeyEventArgs e)
{
    switch ((HardwareKeys)e.KeyCode)
    {
        case HardwareKeys.ApplicationKey1:
            statusBar1.Text = "Button 1 pressed.";
            break;

        case HardwareKeys.ApplicationKey4:
            statusBar1.Text = "Button 4 pressed.";
            break;

        default:
            break;
    }
}

Compiling the Code

This example requires references to the following namespaces:

• System

• Microsoft.WindowsCE.Forms

• System.Windows.Forms

See Also

Reference

HardwareButton

Other Resources

Pocket PC Development and the .NET Compact Framework