几秒钟后关闭MessageBox

请尝试以下方法：

AutoClosingMessageBox.Show("Text", "Caption", 1000);

当

AutoClosingMessageBox

public class AutoClosingMessageBox {    System.Threading.Timer _timeoutTimer;    string _caption;    AutoClosingMessageBox(string text, string caption, int timeout) {        _caption = caption;        _timeoutTimer = new System.Threading.Timer(OnTimerElapsed, null, timeout, System.Threading.Timeout.Infinite);        using(_timeoutTimer) MessageBox.Show(text, caption);    }    public static void Show(string text, string caption, int timeout) {        new AutoClosingMessageBox(text, caption, timeout);    }    void onTimerElapsed(object state) {        IntPtr mbWnd = FindWindow("#32770", _caption); // lpClassName is #32770 for MessageBox        if(mbWnd != IntPtr.Zero) SendMessage(mbWnd, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);        _timeoutTimer.Dispose();    }    const int WM_CLOSE = 0x0010;    [System.Runtime.InteropServices.Dllimport("user32.dll", SetLastError = true)]    static extern IntPtr FindWindow(string lpClassName, string lpWindowName);    [System.Runtime.InteropServices.Dllimport("user32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]    static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);}

更新： 如果希望在超时之前选择某些内容时要获取基础MessageBox的返回值，则可以使用以下版本的代码：

var userResult = AutoClosingMessageBox.Show("Yes or No?", "Caption", 1000, MessageBoxButtons.YesNo);if(userResult == System.Windows.Forms.DialogResult.Yes) {     // do something}...public class AutoClosingMessageBox {    System.Threading.Timer _timeoutTimer;    string _caption;    DialogResult _result;    DialogResult _timerResult;    AutoClosingMessageBox(string text, string caption, int timeout, MessageBoxButtons buttons = MessageBoxButtons.OK, DialogResult timerResult = DialogResult.None) {        _caption = caption;        _timeoutTimer = new System.Threading.Timer(OnTimerElapsed, null, timeout, System.Threading.Timeout.Infinite);        _timerResult = timerResult;        using(_timeoutTimer) _result = MessageBox.Show(text, caption, buttons);    }    public static DialogResult Show(string text, string caption, int timeout, MessageBoxButtons buttons = MessageBoxButtons.OK, DialogResult timerResult = DialogResult.None) {        return new AutoClosingMessageBox(text, caption, timeout, buttons, timerResult)._result;    }    void onTimerElapsed(object state) {        IntPtr mbWnd = FindWindow("#32770", _caption); // lpClassName is #32770 for MessageBox        if(mbWnd != IntPtr.Zero) SendMessage(mbWnd, WM_CLOSE, IntPtr.Zero, IntPtr.Zero);        _timeoutTimer.Dispose();        _result = _timerResult;    }    const int WM_CLOSE = 0x0010;    [System.Runtime.InteropServices.Dllimport("user32.dll", SetLastError = true)]    static extern IntPtr FindWindow(string lpClassName, string lpWindowName);    [System.Runtime.InteropServices.Dllimport("user32.dll", CharSet = System.Runtime.InteropServices.CharSet.Auto)]    static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);}

另一个更新

我用

YesNo

WM_CLOSE

Install-Package AutoClosingMessageBox

发行说明（v1.0.0.2）：
-新的Show（IWin32Owner）API支持大多数流行的场景（在＃1的上下文中）；
-新的Factory（）API提供对MessageBox显示的完全控制；