MS Access中Windows Media Player插件全屏失效问题求助

针对你遇到的WMP插件点击按钮全屏后闪回的问题，可尝试以下几种解决方案：

• 先确保控件获得焦点
  之前正常的代码可能因为控件焦点丢失导致全屏状态被窗体抢占，添加焦点设置后再执行全屏命令：

  Me.wmp.SetFocus
  Dim wmp As Object
  Set wmp = Me.wmp.object
  wmp.fullscreen = True
  

• 禁用窗体重绘避免干扰
  窗体的自动重绘事件可能会强制重置WMP窗口状态，可临时禁用重绘再恢复：

  Me.Repaint = False
  Me.wmp.SetFocus
  Dim wmp As Object
  Set wmp = Me.wmp.object
  wmp.fullscreen = True
  Me.Repaint = True
  

• 用API强制锁定全屏窗口
  若系统或窗体的窗口层级逻辑干扰全屏状态，通过Windows API将WMP窗口置顶锁定：
  首先在模块顶部添加API声明：

  Declare Function SetWindowPos Lib "user32" (ByVal hwnd As Long, ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long
  Const HWND_TOPMOST = -1
  Const SWP_SHOWWINDOW = &H40
  

  然后修改全屏按钮的代码：

  Me.wmp.SetFocus
  Dim wmp As Object
  Set wmp = Me.wmp.object
  wmp.fullscreen = True
  SetWindowPos wmp.hwnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_SHOWWINDOW
  

• 排查后台干扰代码
  检查窗体是否存在定时器（Timer）控件或其他异步执行的VBA代码，这些代码可能在全屏设置后触发窗口状态重置，临时禁用相关代码测试是否恢复正常。

• 确保视频处于播放状态再设置全屏
  部分情况下WMP在暂停状态下全屏设置会出现异常，先触发播放再设置全屏：

  Me.wmp.SetFocus
  Dim wmp As Object
  Set wmp = Me.wmp.object
  wmp.controls.play
  wmp.fullscreen = True
  

内容的提问来源于stack exchange，提问作者Lowendz113