Come utilizzare l'associazione tardiva per ottenere l'istanza di Excel?

Question

Sto usando

[DllImport("Oleacc.dll")] 
static extern int AccessibleObjectFromWindow(
int hwnd, 
uint dwObjectID, 
byte[] riid, 
ref Excel.Window ptr);

per ottenere un'istanza di Excel usando il suo manico, che mi da l'ID del processo dell'istanza excel.

Questo è come sembra quando uso questi funzione

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;

Questa pace del codice di grandi opere, ma l'unico problema è che ho dovuto aggiungere un riferimento al Office 2003 Primary Interop Assemblies.

Come potete vedere, l'ultimo parametro nella funzione è il motivo per cui ho dovuto aggiungere il riferimento al Pias, quindi la mia domanda è se c'è un modo per evitare l'uso di Assiemi di Interop, ho provato con in ritardo, ma forse ho sbagliato perché non sono stato in grado di farlo funzionare.

Answer 1

Primo: il legame tardivo in C# è piuttosto un dolore. È meglio evitarlo. Secondo: il legame tardivo in C# è un dolore. Usa il PIA!

Ok, detto questo, ecco cosa dovete fare per poter utilizzare l'associazione tardiva: Rimuovere il riferimento all'Ufficio PIA 2003 e invece aggiungere un import COM dell'interfaccia richiesta dalla AccessibleObjectFromWindow, vale a dire l'interfaccia Excel.Window:

[Guid("00020893-0000-0000-C000-000000000046")] 
[InterfaceType(ComInterfaceType.InterfaceIsIDispatch)] 
public interface ExcelWindow 
{ 
} 

è possibile recuperare questa interfaccia utilizzando uno strumento come Reflector (o semplicemente premendo F12 dal tipo Excel.Window mentre il riferimento alla Excel PIA è ancora nel progetto)

ciò fatto si avrà per modificare la firma di AccessibleObjectFromWindow per abbinare l'importazione ExcelWindow interfaccia:

[DllImport("Oleacc.dll")] 
static extern int AccessibleObjectFromWindow(int hwnd, uint dwObjectID, byte[] riid, out ExcelWindow ptr); 

Infine, è necessario utilizzare la riflessione per ottenere l'oggetto Excel.Application dall'oggetto ExcelWindow:

object xlApp = ptr.GetType().InvokeMember("Application", BindingFlags.GetProperty, null, ptr, null); 

Se il codice sta per fare un sacco di chiamate in L'OM di Excel potrebbe essere più semplice da utilizzare con VB disattivato (oppure attendere C# 4.0 ;-). Oppure, se non vuoi cambiare da C#, potrebbe essere una buona idea creare una classe wrapper per le ultime chiamate vincolanti.

---

Esempio completa

Ecco un esempio perfettamente funzionante (sulla base di una article da Andrew Whitechapel):

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)); 
         } 
        } 
       } 
      } 
     } 
    } 
} 

E questa sarebbe la stessa soluzione senza PIA in VB (Nota che le chiamate OM sono molto più leggibili, tuttavia, il codice per ottenere l'accesso all'OM sarebbe lo stesso):

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 

Answer 2

no.

So che sembra banale, ma VB è molte, molte volte più facile da usare di C# quando si lavora con Excel. Anche se utilizzi PIA anziché rilegatura in ritardo totale, stai ancora meglio usando VB.

(Nota:. Tutti questi commenti diventeranno immediatamente sbagliato quando C# 4 viene rilasciato)

Answer 3

utilizzare questa definizione di AccessibleObjectFromWindow invece:

[DllImport("Oleacc.dll")] 
    private static extern int AccessibleObjectFromWindow(
     int hwnd, uint dwObjectID, 
     byte[] riid, 
     [MarshalAs(UnmanagedType.IUnknown)]ref object ptr); 

Answer 4

Il codice nella prima risposta ha funzionato come un fascino. Ecco la stessa cosa per Word, oltre a un po 'di azione .NET 4.0 Dynamic in basso.

// 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); 
      } 
     } 
    } 
}