如何使用后期绑定来获得excel实例？
我在用着
[DllImport("Oleacc.dll")] static extern int AccessibleObjectFromWindow( int hwnd, uint dwObjectID, byte[] riid, ref Excel.Window ptr); 使用他的句柄得到一个Excel实例，我从excel实例的进程ID中得到这个句柄。
这是我使用这些function时的样子
const uint OBJID_NATIVEOM = 0xFFFFFFF0; Guid IID_IDispatch = new Guid("{00020400-0000-0000-C000-000000000046}"); Excel.Window ptr = null; int hr = AccessibleObjectFromWindow(hwndChild, OBJID_NATIVEOM, IID_IDispatch.ToByteArray(), ref ptr); Object objApp = ptr.Application;
代码的这种和平效果很好，但唯一的问题是我不得不添加对Office 2003主互操作程序集的引用。
正如你所看到的，函数中的最后一个参数是我需要添加引用到Pias的原因，所以我的问题是如果有一种方法可以避免使用Interop程序集，我已经尝试了后期绑定，但也许我一直在做错了，因为我一直无法做到这一点。
第一：在C＃中的后期绑定是相当痛苦的。 最好避免它。 第二：在C＃中的后期绑定是一个痛苦。 使用PIA！
好吧，这就是为了使用后期绑定而需要做的事情：删除对Office 2003 PIA的引用，而是添加一个COM对象，使用AccessibleObjectFromWindow所需的接口，即Excel.Window接口：
[Guid("00020893-0000-0000-C000-000000000046")] [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)] public interface ExcelWindow { }
您可以使用Reflector等工具来检索此界面（或者只需按下Excel.Windowtypes上的F12，而对Excel PIA的引用仍在您的项目中）
这样做，你将不得不修改的AccessibleObjectFromWindow签名匹配导入的ExcelWindow接口：
[DllImport("Oleacc.dll")] static extern int AccessibleObjectFromWindow(int hwnd, uint dwObjectID, byte[] riid, out ExcelWindow ptr);
最后，您必须使用reflection从ExcelWindow对象中获取Excel.Application对象：
object xlApp = ptr.GetType().InvokeMember("Application", BindingFlags.GetProperty, null, ptr, null);
如果你的代码要打很多电话到Excel的OM中，那么使用VBclosuresOption Strict （或等待C＃4.0 ;-)）可能会更容易一些。 或者，如果您不想从C＃中更改，则为后期绑定调用创build包装类可能是个好主意。
完整的示例
这里是一个function齐全的样本（基于Andrew Whitechapel的一篇文章 ）：
using System; using System.Globalization; using System.Reflection; using System.Runtime.InteropServices; using System.Text; namespace ExcelLateBindingSample { /// <summary> /// Interface definition for Excel.Window interface /// </summary> [Guid("00020893-0000-0000-C000-000000000046")] [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)] public interface ExcelWindow { } /// <summary> /// This class is needed as a workaround to http://support.microsoft.com/default.aspx?scid=kb;en-us;320369 /// Excel automation will fail with the follwoing error on systems with non-English regional settings: /// "Old format or invalid type library. (Exception from HRESULT: 0x80028018 (TYPE_E_INVDATAREAD))" /// </summary> class UILanguageHelper : IDisposable { private CultureInfo _currentCulture; public UILanguageHelper() { // save current culture and set culture to en-US _currentCulture = System.Threading.Thread.CurrentThread.CurrentCulture; System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US"); } public void Dispose() { // reset to original culture System.Threading.Thread.CurrentThread.CurrentCulture = _currentCulture; } } class Program { [DllImport("user32.dll", SetLastError = true)] static extern IntPtr FindWindow(string lpClassName, string lpWindowName); [DllImport("Oleacc.dll")] static extern int AccessibleObjectFromWindow(int hwnd, uint dwObjectID, byte[] riid, out ExcelWindow ptr); public delegate bool EnumChildCallback(int hwnd, ref int lParam); [DllImport("User32.dll")] public static extern bool EnumChildWindows(int hWndParent, EnumChildCallback lpEnumFunc, ref int lParam); [DllImport("User32.dll")] public static extern int GetClassName(int hWnd, StringBuilder lpClassName, int nMaxCount); public static bool EnumChildProc(int hwndChild, ref int lParam) { StringBuilder buf = new StringBuilder(128); GetClassName(hwndChild, buf, 128); if (buf.ToString() == "EXCEL7") { lParam = hwndChild; return false; } return true; } static void Main(string[] args) { // Use the window class name ("XLMAIN") to retrieve a handle to Excel's main window. // Alternatively you can get the window handle via the process id: // int hwnd = (int)Process.GetProcessById(excelPid).MainWindowHandle; // int hwnd = (int)FindWindow("XLMAIN", null); if (hwnd != 0) { int hwndChild = 0; // Search the accessible child window (it has class name "EXCEL7") EnumChildCallback cb = new EnumChildCallback(EnumChildProc); EnumChildWindows(hwnd, cb, ref hwndChild); if (hwndChild != 0) { // We call AccessibleObjectFromWindow, passing the constant OBJID_NATIVEOM (defined in winuser.h) // and IID_IDispatch - we want an IDispatch pointer into the native object model. // const uint OBJID_NATIVEOM = 0xFFFFFFF0; Guid IID_IDispatch = new Guid("{00020400-0000-0000-C000-000000000046}"); ExcelWindow ptr; int hr = AccessibleObjectFromWindow(hwndChild, OBJID_NATIVEOM, IID_IDispatch.ToByteArray(), out ptr); if (hr >= 0) { // We successfully got a native OM IDispatch pointer, we can QI this for // an Excel Application using reflection (and using UILanguageHelper to // fix http://support.microsoft.com/default.aspx?scid=kb;en-us;320369) // using (UILanguageHelper fix = new UILanguageHelper()) { object xlApp = ptr.GetType().InvokeMember("Application", BindingFlags.GetProperty, null, ptr, null); object version = xlApp.GetType().InvokeMember("Version", BindingFlags.GetField | BindingFlags.InvokeMethod | BindingFlags.GetProperty, null, xlApp, null); Console.WriteLine(string.Format("Excel version is: {0}", version)); } } } } } } }
在VB中没有PIA也是同样的解决方法（请注意，OM调用的可读性要高得多;但是访问OM的代码是相同的）：
Option Strict Off Imports System.Globalization Imports System.Runtime.InteropServices Imports System.Text Module ExcelLateBindingSample ''' <summary> ''' Interface definition for Excel.Window interface ''' </summary> <Guid("00020893-0000-0000-C000-000000000046"), _ InterfaceType(ComInterfaceType.InterfaceIsIDispatch)> _ Public Interface ExcelWindow End Interface ''' <summary> ''' This class is needed as a workaround to http://support.microsoft.com/default.aspx?scid=kb;en-us;320369 ''' Excel automation will fail with the follwoing error on systems with non-English regional settings: ''' "Old format or invalid type library. (Exception from HRESULT: 0x80028018 (TYPE_E_INVDATAREAD))" ''' </summary> Class UILanguageHelper Implements IDisposable Private _currentCulture As CultureInfo Public Sub New() ' save current culture and set culture to en-US _currentCulture = System.Threading.Thread.CurrentThread.CurrentCulture System.Threading.Thread.CurrentThread.CurrentCulture = New CultureInfo("en-US") End Sub Public Sub Dispose() Implements System.IDisposable.Dispose 'reset to original culture System.Threading.Thread.CurrentThread.CurrentCulture = _currentCulture End Sub End Class <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _ Private Function FindWindow(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr End Function <DllImport("Oleacc.dll")> _ Private Function AccessibleObjectFromWindow(ByVal hwnd As Integer, ByVal dwObjectID As UInt32, ByVal riid() As Byte, ByRef ptr As ExcelWindow) As Integer End Function Public Delegate Function EnumChildCallback(ByVal hwnd As Integer, ByRef lParam As Integer) As Boolean <DllImport("User32.dll")> _ Public Function EnumChildWindows(ByVal hWndParent As Integer, ByVal lpEnumFunc As EnumChildCallback, ByRef lParam As Integer) As Boolean End Function <DllImport("User32.dll")> _ Public Function GetClassName(ByVal hWnd As Integer, ByVal lpClassName As StringBuilder, ByVal nMaxCount As Integer) As Integer End Function Public Function EnumChildProc(ByVal hwndChild As Integer, ByRef lParam As Integer) As Boolean Dim buf As New StringBuilder(128) GetClassName(hwndChild, buf, 128) If buf.ToString() = "EXCEL7" Then lParam = hwndChild Return False End If Return True End Function Sub Main() ' Use the window class name ("XLMAIN") to retrieve a handle to Excel's main window. ' Alternatively you can get the window handle via the process id: ' Dim hwnd As Integer = CInt(Process.GetProcessById(excelPid).MainWindowHandle); ' Dim hwnd As Integer = CInt(FindWindow("XLMAIN", Nothing)) If hwnd <> 0 Then Dim hwndChild As Integer = 0 ' Search the accessible child window (it has class name "EXCEL7") Dim cb As New EnumChildCallback(AddressOf EnumChildProc) EnumChildWindows(hwnd, cb, hwndChild) If hwndChild <> 0 Then ' We call AccessibleObjectFromWindow, passing the constant OBJID_NATIVEOM (defined in winuser.h) ' and IID_IDispatch - we want an IDispatch pointer into the native object model. ' Const OBJID_NATIVEOM As UInteger = &HFFFFFFF0& Dim IID_IDispatch As New Guid("{00020400-0000-0000-C000-000000000046}") Dim ptr As ExcelWindow Dim hr As Integer = AccessibleObjectFromWindow(hwndChild, OBJID_NATIVEOM, IID_IDispatch.ToByteArray(), ptr) If hr >= 0 Then ' We successfully got a native OM IDispatch pointer, we can QI this for ' an Excel Application using reflection (and using UILanguageHelper to ' fix http://support.microsoft.com/default.aspx?scid=kb;en-us;320369) ' Using fixCrash As New UILanguageHelper Console.WriteLine(String.Format("Excel version is: {0}", ptr.Application.Version)) End Using End If End If End If End Sub End Module
改为使用AccessibleObjectFromWindow的这个定义：
[DllImport("Oleacc.dll")] private static extern int AccessibleObjectFromWindow( int hwnd, uint dwObjectID, byte[] riid, [MarshalAs(UnmanagedType.IUnknown)]ref object ptr);
第一个答案中的代码就像一个魅力。 对于Word来说，这是一样的，再加上一些.NET 4.0 Dynamic动作。
// http://stackoverflow.com/questions/779363/how-to-use-use-late-binding-to-get-excel-instance // ReSharper disable InconsistentNaming using System; using System.Runtime.InteropServices; using System.Globalization; using System.Reflection; using System.Text; namespace LateBindingWord { /// <summary> Interface definition for Word.Window interface </summary> [Guid("00020962-0000-0000-C000-000000000046")] [InterfaceType(ComInterfaceType.InterfaceIsIDispatch)] public interface IWordWindow { } /// <summary> /// This class is needed as a workaround to http://support.microsoft.com/default.aspx?scid=kb;en-us;320369 /// Excel automation will fail with the follwoing error on systems with non-English regional settings: /// "Old format or invalid type library. (Exception from HRESULT: 0x80028018 (TYPE_E_INVDATAREAD))" /// </summary> class UiLanguageHelper : IDisposable { private readonly CultureInfo _currentCulture; public UiLanguageHelper() { // save current culture and set culture to en-US _currentCulture = System.Threading.Thread.CurrentThread.CurrentCulture; System.Threading.Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US"); } public void Dispose() { // reset to original culture System.Threading.Thread.CurrentThread.CurrentCulture = _currentCulture; } } class Program { [DllImport("user32.dll", SetLastError = true)] static extern IntPtr FindWindow(string lpClassName, string lpWindowName); [DllImport("Oleacc.dll")] static extern int AccessibleObjectFromWindow(int hwnd, uint dwObjectID, byte[] riid, out IWordWindow ptr); public delegate bool EnumChildCallback(int hwnd, ref int lParam); [DllImport("User32.dll")] public static extern bool EnumChildWindows(int hWndParent, EnumChildCallback lpEnumFunc, ref int lParam); [DllImport("User32.dll")] public static extern int GetClassName(int hWnd, StringBuilder lpClassName, int nMaxCount); public static bool EnumChildProc(int hwndChild, ref int lParam) { var buf = new StringBuilder(128); GetClassName(hwndChild, buf, 128); Console.WriteLine(buf.ToString()); if (buf.ToString() == "_WwG") { lParam = hwndChild; return false; } return true; } static void Main() { // Use the window class name ("XLMAIN") to retrieve a handle to Excel's main window. // Alternatively you can get the window handle via the process id: // int hwnd = (int)Process.GetProcessById(excelPid).MainWindowHandle; // var p=Process.GetProcesses().FirstOrDefault(x => x.ProcessName=="WINWORD"); var hwnd = (int) FindWindow("OpusApp", null); if (hwnd == 0) throw new Exception("Can't find Word"); // Search the accessible child window (it has class name "_WwG") // http://msdn.microsoft.com/en-us/library/windows/desktop/dd317978%28v=vs.85%29.aspx var hwndChild = 0; var cb = new EnumChildCallback(EnumChildProc); EnumChildWindows(hwnd, cb, ref hwndChild); if (hwndChild == 0) throw new Exception("Can't find Automation Child Window"); // We call AccessibleObjectFromWindow, passing the constant OBJID_NATIVEOM (defined in winuser.h) // and IID_IDispatch - we want an IDispatch pointer into the native object model. const uint OBJID_NATIVEOM = 0xFFFFFFF0; var IID_IDispatch = new Guid("{00020400-0000-0000-C000-000000000046}"); IWordWindow ptr; var hr = AccessibleObjectFromWindow(hwndChild, OBJID_NATIVEOM, IID_IDispatch.ToByteArray(), out ptr); if (hr < 0) throw new Exception("Can't get Accessible Object"); // We successfully got a native OM IDispatch pointer, we can QI this for // an Excel Application using reflection (and using UILanguageHelper to // fix http://support.microsoft.com/default.aspx?scid=kb;en-us;320369) using (new UiLanguageHelper()) { var wordApp = ptr.GetType().InvokeMember("Application", BindingFlags.GetProperty, null, ptr, null); var version = wordApp.GetType().InvokeMember("Version", BindingFlags.GetField | BindingFlags.InvokeMethod | BindingFlags.GetProperty, null, wordApp, null); Console.WriteLine("Word version is: {0}", version); dynamic wordAppd = ptr.GetType().InvokeMember("Application", BindingFlags.GetProperty, null, ptr, null); Console.WriteLine("Version: " + wordAppd.Version); } } } }
别。
我知道这听起来很古怪，但在使用Excel时，VB比C＃更容易使用。 即使你使用PIA而不是全部的晚期绑定，你仍然使用VB更好。
（注意：当C＃4发布时，所有这些注释将立即变得错误。）