c# - .net cf TextBox 显示键盘焦点

Question

我的 UI 上有几个文本框，我想在控件获得焦点时显示移动键盘，然后消失。

注意:对于这个特定的程序，它是一个高屏幕并且设备上没有物理键盘。

Answer 1

将 InputPanel 添加到您的表单，连接 TextBox 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;
}

更新

响应ctacke的完整性要求；这是连接事件处理程序的示例代码。通常我会为此使用设计器(选择文本框，显示属性网格，切换到事件列表并让环境为 GotFocus 和 LostFocus 设置处理程序)，但如果 UI 包含多个文本框，您可能希望它更加自动化。

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();
}