强制创建WPF Window的本机Win32句柄

4 回答

• 1

  一种选择是将窗口状态设置为最小化，而不是在显示窗口之前显示在任务栏中 . 尝试这样的事情 .

  IntPtr hWnd;
    WindowInteropHelper helper = new WindowInteropHelper(wnd);
  
    WindowState prevState = wnd.WindowState;
    bool prevShowInTaskBar = wnd.ShowInTaskbar;
  
    wnd.ShowInTaskbar = false;
    wnd.WindowState = WindowState.Minimized;
    wnd.Show();
    hWnd = helper.Handle;
    wnd.Hide();
  
    wnd.ShowInTaskbar = prevShowInTaskBar;
    wnd.WindowState = prevState;
  

  回复于 2024-05-03T17:49:15+08:00
• 2

  使用WindowInteropHelper.EnsureHandle，它完全符合您的需要 .

  回复于 2024-05-03T17:49:15+08:00
• 3

  如果WindowInteropHelper的句柄为NULL，我正在寻找解决方案 . 希望这篇文章提供了一些如何解决它的其他信息 .

  一种解决方案是使用：

  var window = new Window();
  var handle = new WindowInteropHelper(window).EnsureHandle()
  

  这仅适用于.NET Framework 4 .

  目前我正在使用.NET Framework 3.5，所以我需要另一种解决方案 . 然后我找到了一个带有WindowInteropHelper扩展方法的论坛帖子：

  #region
  
  using System;
  using System.Reflection;
  using System.Windows;
  using System.Windows.Interop;
  
  #endregion
  
  namespace System.Windows.Interop
  {
      /// <summary>
      ///   Provides NetFX 4.0 EnsureHandle method for
      ///   NetFX 3.5 WindowInteropHelper class.
      /// </summary>
      public static class WindowInteropHelperExtension
      {
          /// <summary>
          ///   Creates the HWND of the window if the HWND has not been created yet.
          /// </summary>
          /// <param name = "helper">An instance of WindowInteropHelper class.</param>
          /// <returns>An IntPtr that represents the HWND.</returns>
          /// <remarks>
          ///   Use the EnsureHandle method when you want to separate
          ///   window handle (HWND) creation from the
          ///   actual showing of the managed Window.
          /// </remarks>
          public static IntPtr EnsureHandle(this WindowInteropHelper helper)
          {
              if (helper == null)
                  throw new ArgumentNullException("helper");
  
              if (helper.Handle == IntPtr.Zero)
              {
                  var window = (Window) typeof (WindowInteropHelper).InvokeMember(
                      "_window",
                      BindingFlags.GetField |
                      BindingFlags.Instance |
                      BindingFlags.NonPublic,
                      null, helper, null);
  
                  typeof (Window).InvokeMember(
                      "SafeCreateWindow",
                      BindingFlags.InvokeMethod |
                      BindingFlags.Instance |
                      BindingFlags.NonPublic,
                      null, window, null);
              }
  
              return helper.Handle;
          }
      }
  }
  

  WindowInteropHelper.EnsureHandle（）不期望已经创建了一个窗口 .

  参考：Alexander Yudakov - http://social.msdn.microsoft.com/Forums/en-MY/wpf/thread/5f89ac58-d2ef-4ac0-aefb-b2826dbef48a

  回复于 2024-05-03T17:49:15+08:00
• 19

  我遇到了同样的问题并且使用J Pollack's answer（因为它对我来说似乎更干净），但需要在.NET运行时2.0和4.0上运行的东西 .

  但是当我这样做时，我最终得到了一个丑陋的MissingMethodException因为.NET运行时4.0中不再存在 SafeCreateWindow . 为了使代码在两个运行时都能工作，我决定捕获MissingMethodException并在.NET 4.0运行时调用等效代码，如下所示：

  public static IntPtr EnsureHandle(this WindowInteropHelper helper)
      {
          if (helper == null)
              throw new ArgumentNullException("helper");
  
          if (helper.Handle == IntPtr.Zero)
          {
              var window = (Window)typeof(WindowInteropHelper).InvokeMember(
                  "_window",
                  BindingFlags.GetField |
                  BindingFlags.Instance |
                  BindingFlags.NonPublic,
                  null, helper, null);
  
              try
              {
                  // SafeCreateWindow only exists in the .NET 2.0 runtime. If we try to
                  // invoke this method on the .NET 4.0 runtime it will result in a
                  // MissingMethodException, see below.
                  typeof(Window).InvokeMember(
                      "SafeCreateWindow",
                      BindingFlags.InvokeMethod |
                      BindingFlags.Instance |
                      BindingFlags.NonPublic,
                      null, window, null);
              }
              catch (MissingMethodException)
              {
                  // If we ended up here it means we are running on the .NET 4.0 runtime,
                  // where the method we need to call for the handle was renamed/replaced
                  // with CreateSourceWindow.
                  typeof(Window).InvokeMember(
                      "CreateSourceWindow",
                      BindingFlags.InvokeMethod |
                      BindingFlags.Instance |
                      BindingFlags.NonPublic,
                      null, window, new object[] { false });
              }
          }
  
          return helper.Handle;
      }
  

  这允许我使用.NET 3.5编译代码，但是在安装了更高运行时版本的系统（即Windows 8及更高版本）上的.NET运行时4.0上运行它 .

  回复于 2024-05-03T17:49:15+08:00