如何：使用 HardwareButton 组件
更新：2007 年 11 月
您可以在 Pocket PC 上配置硬件按钮以激活 Form。本示例使用第一个和第四个硬件按钮激活某个应用程序，并在状态栏中指示按下了哪个按钮。
设置硬件按钮以激活窗体
创建一个 Pocket PC Windows 应用程序。
创建一个 HardwareButton 的实例。
将 AssociatedControl 属性设置为窗体。
将 HardwareKey 属性设置为由 HardwareKeys 枚举定义的应用程序键。
对于要使用的其他硬件按钮，重复第 2 步至第 4 步。
当按下并松开某硬件按钮时，窗体既会收到 KeyDown 事件也会收到 KeyUp 事件。您可以使用任意一个事件确定是否曾按下某个硬件按钮。
示例
本示例设置第一个和第四个硬件按钮以激活窗体。若要进行演示，请按下列步骤操作：
运行该应用程序。
在设备上打开另一应用程序。
按硬件按钮 1 或 4 以激活该应用程序的窗体。状态栏指示按下了哪个硬件按钮。
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;
}
}
编译代码
此示例需要引用下面的命名空间：