在表单中添加InputPanel,连接文本框的GotFocus和LostFocus事件,并在事件处理程序中显示/隐藏输入面板:
private void TextBox_GotFocus(object sender, EventArgs e)
{
SetKeyboardVisible(true);
}
private void TextBox_LostFocus(object sender, EventArgs e)
{
SetKeyboardVisible(false);
}
protected void SetKeyboardVisible(bool isVisible)
{
inputPanel.Enabled = isVisible;
}
使现代化
GotFocus
LostFocus
下面的类公开了两个静态方法,AttachGotLostFocusEvents和DetachGotLostFocusEvents;它们接受一个ControlCollection和两个事件处理程序。
internal static class ControlHelper
{
private static bool IsGotLostFocusControl(Control ctl)
{
return ctl.GetType().IsSubclassOf(typeof(TextBoxBase)) ||
(ctl.GetType() == typeof(ComboBox) && (ctl as ComboBox).DropDownStyle == ComboBoxStyle.DropDown);
}
public static void AttachGotLostFocusEvents(
System.Windows.Forms.Control.ControlCollection controls,
EventHandler gotFocusEventHandler,
EventHandler lostFocusEventHandler)
{
foreach (Control ctl in controls)
{
if (IsGotLostFocusControl(ctl))
{
ctl.GotFocus += gotFocusEventHandler;
ctl.LostFocus += lostFocusEventHandler ;
}
else if (ctl.Controls.Count > 0)
{
AttachGotLostFocusEvents(ctl.Controls, gotFocusEventHandler, lostFocusEventHandler);
}
}
}
public static void DetachGotLostFocusEvents(
System.Windows.Forms.Control.ControlCollection controls,
EventHandler gotFocusEventHandler,
EventHandler lostFocusEventHandler)
{
foreach (Control ctl in controls)
{
if (IsGotLostFocusControl(ctl))
{
ctl.GotFocus -= gotFocusEventHandler;
ctl.LostFocus -= lostFocusEventHandler;
}
else if (ctl.Controls.Count > 0)
{
DetachGotLostFocusEvents(ctl.Controls, gotFocusEventHandler, lostFocusEventHandler);
}
}
}
}
表单中的用法示例:
private void Form_Load(object sender, EventArgs e)
{
ControlHelper.AttachGotLostFocusEvents(
this.Controls,
new EventHandler(EditControl_GotFocus),
new EventHandler(EditControl_LostFocus));
}
private void Form_Closed(object sender, EventArgs e)
{
ControlHelper.DetachGotLostFocusEvents(
this.Controls,
new EventHandler(EditControl_GotFocus),
new EventHandler(EditControl_LostFocus));
}
private void EditControl_GotFocus(object sender, EventArgs e)
{
ShowKeyboard();
}
private void EditControl_LostFocus(object sender, EventArgs e)
{
HideKeyboard();
}