Question

问题：我正在编写Word 2013加载项/插件/ VSTO，需要拦截来自/到我的插件所在的Word实例的拖放事件运行。

解决方案：我正在尝试将RegisterDragDrop function与IDropTarget的实现一起用于传递到寄存器功能。不幸的是，我的IDropTarget实现中的所有事件都没有触发。我猜我错过了一些东西，或者甚至连插件都没有。

问题：

如果可以，我将传递给RegisterDragDrop方法的句柄是什么？它是插件的句柄吗？ MS-Word实例本身的句柄？
如果无法做到这一点，那么使用Windows Procedures（挂钩Windows调用）是否是一个潜在的解决方案？

这是我的代码：

NativeMethods.cs：

// See: http://msdn.microsoft.com/en-us/library/windows/desktop/ms678405(v=vs.85).aspx
[DllImport("ole32.dll")]
public static extern int RegisterDragDrop(IntPtr hwnd, IDropTarget pDropTarget);

ThisAddIn.cs：

private void ThisAddIn_Startup(object sender, EventArgs e)
{
    int temp = 0;
    Process[] pWords = Process.GetProcessesByName("WINWORD");
    foreach (Process process in pWords)
    {
        temp = process.Id;
    }

    NativeMethods.RegisterDragDrop(Process.GetProcessById(temp).Handle, new MyDropTarget())
}

MyDropTarget.cs：

public class MyDropTarget : IDropTarget
{
    public void OnDragDrop(DragEventArgs e)
    {
        throw new NotImplementedException();
    }

    public void OnDragEnter(DragEventArgs e)
    {
        throw new NotImplementedException();
    }

    public void OnDragLeave(EventArgs e)
    {
        throw new NotImplementedException();
    }

    public void OnDragOver(DragEventArgs e)
    {
        throw new NotImplementedException();
    }
}

Answer 1

可以使用RegisterDragDrop函数，但在此之前，你需要调用RevokeDragDrop，你可以得到这样的句柄：

  [DllImport("User32.dll", EntryPoint = "FindWindow")]
    public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
    [DllImport("user32.dll", SetLastError = true)]
    public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
 private  static IntPtr GetCurrentWindowHandle()
    {
        IntPtr windowHandle = IntPtr.Zero;

        windowHandle = FindWindow("OpusApp", null);

        windowHandle = FindWindowEx(windowHandle, IntPtr.Zero, "_WwF", null);
        windowHandle = FindWindowEx(windowHandle, IntPtr.Zero, "_WwB", null);
        windowHandle = FindWindowEx(windowHandle, IntPtr.Zero, "_WwG", null);

        return windowHandle;
    }

这是我的代码：

   [ComImport, Guid("00000122-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface IOleDropTarget
{
    [PreserveSig]
    int OleDragEnter([In, MarshalAs(UnmanagedType.Interface)] object pDataObj, [In, MarshalAs(UnmanagedType.U4)] int grfKeyState, [In, MarshalAs(UnmanagedType.U8)] long pt, [In, Out] ref int pdwEffect);
    [PreserveSig]
    int OleDragOver([In, MarshalAs(UnmanagedType.U4)] int grfKeyState, [In, MarshalAs(UnmanagedType.U8)] long pt, [In, Out] ref int pdwEffect);
    [PreserveSig]
    int OleDragLeave();
    [PreserveSig]
    int OleDrop([In, MarshalAs(UnmanagedType.Interface)] object pDataObj, [In, MarshalAs(UnmanagedType.U4)] int grfKeyState, [In, MarshalAs(UnmanagedType.U8)] long pt, [In, Out] ref int pdwEffect);
}

internal class MyDropTarget : IOleDropTarget
{
    [DllImport("ole32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
    public static extern int RegisterDragDrop(IntPtr hwnd, IOleDropTarget target);

    [DllImport("ole32.dll", CharSet = CharSet.Auto, ExactSpelling = true)]
    public static extern int RevokeDragDrop(IntPtr hwnd);
    public int OleDragEnter(object pDataObj, int grfKeyState, long pt, ref int pdwEffect)
    {
        throw new NotImplementedException();
    }

    public int OleDragOver(int grfKeyState, long pt, ref int pdwEffect)
    {
        throw new NotImplementedException();
    }

    public int OleDragLeave()
    {
        throw new NotImplementedException();
    }

    public int OleDrop(object pDataObj, int grfKeyState, long pt, ref int pdwEffect)
    {
        throw new NotImplementedException();
    }
}

像这样使用它：

  var hwnd = GetCurrentWindowHandle();
            MyDropTarget.RevokeDragDrop(hwnd);
            var rtn = MyDropTarget.RegisterDragDrop(hwnd, new MyDropTarget());

Answer 2

您是否检查了RegisterDragDrop调用的返回值？您可能会重新获得DRAGDROP_E_ALREADYREGISTERED，除非您传入的窗口句柄无效，在这种情况下您将获得DRAGDROP_E_INVALIDHWND。不确定你获取窗户的方式是正确的。

Word应该已经将其窗口注册为放置目标，因此您可能需要在注册自己的窗口句柄之前调用RevokeDragDrop。但是，如果您想检查drop上的IDataObject并且只处理某些事情并让Word处理其他内容，这会让您遇到麻烦。（在这种情况下，你需要做更多的工作）

使用Microsoft Word插件/ VSTO拦截拖放事件

2 个答案: