如何让WinForm应用在Windows 10平板模式下强制置顶？

方法1：修改WinForms应用代码（推荐） #

针对你自己开发的简易WinForms应用，直接通过代码设置窗口置顶，同时调用Windows API确保在平板模式下的层级优先级：

Imports System.Runtime.InteropServices
Imports System.Diagnostics

Public Class CountdownForm
    ' 导入Windows API用于强制置顶窗口
    <DllImport("user32.dll")>
    Private Shared Function SetWindowPos(hWnd As IntPtr, hWndInsertAfter As IntPtr, X As Integer, Y As Integer, cx As Integer, cy As Integer, uFlags As UInteger) As Boolean
    End Function

    ' 置顶相关常量定义
    Private Const HWND_TOPMOST As IntPtr = -1
    Private Const SWP_NOMOVE As UInteger = &H2
    Private Const SWP_NOSIZE As UInteger = &H1
    Private Const SWP_SHOWWINDOW As UInteger = &H40

    ' 倒计时时长（秒）
    Private remainingTime As Integer = 60

    Private Sub CountdownForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' 基础置顶设置
        Me.TopMost = True
        ' 调用API强制窗口置顶，覆盖平板模式系统界面
        SetWindowPos(Me.Handle, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE Or SWP_NOSIZE Or SWP_SHOWWINDOW)
        ' 激活窗口确保焦点
        Me.Activate()
        ' 启动倒计时定时器
        Timer1.Interval = 1000
        Timer1.Start()
        UpdateCountdownLabel()
    End Sub

    Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
        remainingTime -= 1
        UpdateCountdownLabel()
        If remainingTime <= 0 Then
            Timer1.Stop()
            ' 执行强制关机命令（需管理员权限）
            Process.Start("shutdown", "/s /t 0 /f")
            Me.Close()
        End If
    End Sub

    Private Sub UpdateCountdownLabel()
        lblCountdown.Text = $"即将关机：{remainingTime}秒"
    End Sub

    ' 可选：禁止用户关闭窗口
    Private Sub CountdownForm_FormClosing(sender As Object, e As FormClosingEventArgs) Handles MyBase.FormClosing
        If remainingTime > 0 Then
            e.Cancel = True
        End If
    End Sub
End Class

关键说明：

• SetWindowPos API会将窗口设置为系统级最顶层，优先级高于平板模式的开始界面
• 需确保应用以管理员权限运行，否则无法执行关机命令
• 可通过Me.WindowState = FormWindowState.Maximized设置全屏显示，适配平板屏幕

方法2：纯VBS/HTA独立弹窗方案 #

如果你不想修改现有WinForms应用，可使用HTA（Windows自带HTML应用）实现置顶倒计时窗口，无需额外开发环境：

创建名为ShutdownTimer.hta的文件，粘贴以下内容：

<!DOCTYPE html>
<html>
<head>
    <title>强制关机通知</title>
    <hta:application 
        topmost="yes"
        showintaskbar="no"
        windowstate="normal"
        border="thick"
        caption="yes"
        contextmenu="no"
    />
    <style>
        body { 
            background: #dc3545; 
            color: white; 
            font-family:微软雅黑; 
            text-align:center; 
            padding:60px 20px;
            margin:0;
        }
        .timer { font-size:60px; font-weight:bold; margin:30px 0; }
        .tip { font-size:24px; }
    </style>
</head>
<body>
    <h1>设备即将强制关机！</h1>
    <div class="timer" id="countdown">60</div>
    <p class="tip">请立即保存工作并关闭程序</p>

    <script language="VBScript">
        Dim leftTime: leftTime = 60 ' 设置倒计时秒数

        Sub Window_OnLoad
            ' 适配平板屏幕居中显示
            Me.ResizeTo 500, 350
            Me.MoveTo (Screen.Width - 500)/2, (Screen.Height - 350)/2
            Call UpdateTimer()
        End Sub

        Sub UpdateTimer
            leftTime = leftTime - 1
            document.getElementById("countdown").innerText = leftTime
            If leftTime <= 0 Then
                ' 执行强制关机
                Set objShell = CreateObject("WScript.Shell")
                objShell.Run "shutdown /s /t 0 /f", 0, False
                Window.Close()
            Else
                window.setTimeout "UpdateTimer()", 1000
            End If
        End Sub
    </script>
</body>
</html>

使用方式：

• 双击运行该HTA文件，窗口会自动在平板模式主屏幕置顶
• 右键以管理员身份运行，确保关机命令生效

内容的提问来源于stack exchange，提问作者Rohab12321