Question

以下是我使用ILSpy获得的代码：

public static object InvokeScript(this IHTMLDocument2 document, string scriptName, object[] args = null)
{
    object result = null;
    UnsafeNativeMethods.tagDISPPARAMS tagDISPPARAMS = new UnsafeNativeMethods.tagDISPPARAMS();
    tagDISPPARAMS.rgvarg = IntPtr.Zero;
    try
    {
        UnsafeNativeMethods.IDispatch dispatch = ((IHTMLDocument)document).Script as UnsafeNativeMethods.IDispatch;
        if (dispatch != null)
        {
            Guid empty = Guid.Empty;
            string[] rgszNames = new string[]
            {
                scriptName
            };
            int[] array = new int[]
            {
                -1
            };
            int iDsOfNames = dispatch.GetIDsOfNames(ref empty, rgszNames, 1, UnsafeNativeMethods.GetThreadLCID(), array);
            if (UnsafeNativeMethods.Succeeded(iDsOfNames) && array[0] != -1)
            {
                if (args != null)
                {
                    Array.Reverse(args);
                }
                tagDISPPARAMS.rgvarg = ((args == null) ? IntPtr.Zero : ArrayToVARIANTVector(args));
                tagDISPPARAMS.cArgs = ((args == null) ? 0 : args.Length);
                tagDISPPARAMS.rgdispidNamedArgs = IntPtr.Zero;
                tagDISPPARAMS.cNamedArgs = 0;
                object[] array2 = new object[1];
                if (dispatch.Invoke(array[0], ref empty, UnsafeNativeMethods.GetThreadLCID(), 1, tagDISPPARAMS, array2, new UnsafeNativeMethods.tagEXCEPINFO(), null) == 0)
                {
                    result = array2[0];
                }
            }
        }
    }
    catch (Exception ex)
    {
        if (IsSecurityOrCriticalException(ex))
        {
            throw;
        }
    }
    finally
    {
        if (tagDISPPARAMS.rgvarg != IntPtr.Zero)
        {
            FreeVARIANTVector(tagDISPPARAMS.rgvarg, args.Length);
        }
    }
    return result;
}

我还有一些从这个方法调用的其他方法。这是我如何称呼它（注意是一种扩展方法）：

var doc = Browser.Document.DomDocument as IHTMLDocument2;
doc.InvokeScript("alert", new object[] { "hi" });

但是行int iDsOfNames = dispatch.GetIDsOfNames(ref empty, rgszNames, 1, UnsafeNativeMethods.GetThreadLCID(), array);会抛出AccessViolationException。我不确定的一件事是UnsafeNativeMethods.IDispatch dispatch = ((IHTMLDocument)document).Script as UnsafeNativeMethods.IDispatch;行。实际的ILSpy行是UnsafeNativeMethods.IDispatch dispatch = this.NativeHtmlDocument2.GetScript() as UnsafeNativeMethods.IDispatch;但由于某种原因我没有GetScript方法。

知道我做错了什么吗？

修改的

这是我的IDispatch：

    [Guid("00020400-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), SuppressUnmanagedCodeSecurity]
    [ComImport]
    internal interface IDispatch
    {
        [SecurityCritical]
        void GetTypeInfoCount(out uint pctinfo);
        [SecurityCritical]
        void GetTypeInfo(uint iTInfo, int lcid, out IntPtr info);
        [SecurityCritical]
        void GetIDsOfNames(ref Guid iid, [MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.LPWStr, SizeParamIndex = 2)] string[] names, uint cNames, int lcid, [MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.I4, SizeParamIndex = 2)] [Out] int[] rgDispId);
        [PreserveSig]
        int GetIDsOfNames([In] ref Guid riid, [MarshalAs(UnmanagedType.LPArray)] [In] string[] rgszNames, [MarshalAs(UnmanagedType.U4)] [In] int cNames, [MarshalAs(UnmanagedType.U4)] [In] int lcid, [MarshalAs(UnmanagedType.LPArray)] [Out] int[] rgDispId);
        [SecurityCritical]
        void Invoke(int dispIdMember, ref Guid riid, int lcid, System.Runtime.InteropServices.ComTypes.INVOKEKIND wFlags, ref System.Runtime.InteropServices.ComTypes.DISPPARAMS pDispParams, IntPtr pvarResult, IntPtr pExcepInfo, IntPtr puArgErr);
        [PreserveSig]
        int Invoke(int dispIdMember, [In] ref Guid riid, [MarshalAs(UnmanagedType.U4)] [In] int lcid, [MarshalAs(UnmanagedType.U4)] [In] int dwFlags, [In] [Out] tagDISPPARAMS pDispParams, [MarshalAs(UnmanagedType.LPArray)] [Out] object[] pVarResult, [In] [Out] tagEXCEPINFO pExcepInfo, [MarshalAs(UnmanagedType.LPArray)] [Out] IntPtr[] pArgErr);
    }

Answer 1

编辑：GetIDsOfNames中的dispid参数是一个调用者提供的数组，因此你不能使用[out]（这意味着被调用者在COM堆上分配数组）。

很难说没有看到UnsafeNativeMethods.IDispatch的声明，但是在没有固定dispid数组或在参数中添加ref的情况下调用GetIDsOfNames是错误的。如果通过按值传递地址来封送数组，则垃圾收集器可以在GetIDsOfNames调用仍在运行时移动数组，并且本机代码将在返回时写入野指针。如果将数组作为引用传递，则代码将无法编译 - 您需要在参数中添加ref。

您可以使用System.Type.InvokeMember方法通过脚本对象访问全局变量或函数。此方法会为您调用IDispatch::GetIDsOfNames和IDispatch::Invoke。

反编译的HtmlDocument的InvokeScript无法正常工作

1 个答案: