反编译的HtmlDocument的InvokeScript无法正常工作 [英] Decompiled HtmlDocument's InvokeScript not working
问题描述
这是我使用ILSpy获得的代码:
Here is the code I got using ILSpy:
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;
}
我还从该方法中调用了其他一些方法.这是我的称呼(注意是扩展方法):
I also got some of their other methods that are being called from this method. Here is how I call it (note is an extension method):
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);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;，但是由于某些原因，我没有GetScript方法.
But the line int iDsOfNames = dispatch.GetIDsOfNames(ref empty, rgszNames, 1, UnsafeNativeMethods.GetThreadLCID(), array); throws an AccessViolationException. One thing I'm not sure about is the UnsafeNativeMethods.IDispatch dispatch = ((IHTMLDocument)document).Script as UnsafeNativeMethods.IDispatch; line. The actual ILSpy line is UnsafeNativeMethods.IDispatch dispatch = this.NativeHtmlDocument2.GetScript() as UnsafeNativeMethods.IDispatch; but for some reason I don't have the GetScript method.
知道我在做什么错吗?
编辑
这是我的IDispatch:
Here is my 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);
}
推荐答案
GetIDsOfNames中的dispid参数是调用方提供的数组，因此不能使用[out](这意味着被调用方在COM堆上分配了该数组)
the dispid parameter in GetIDsOfNames is a caller provided array, thus you cannot use [out] (it means the callee allocate the array on the COM heap).
很难说出没有看到您对UnsafeNativeMethods.IDispatch的声明，但是在不固定dispid数组或向参数添加引用的情况下调用GetIDsOfNames是错误的.如果通过按值传递地址来整理数组，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通配指针.如果将数组作为引用传递，则您的代码将无法编译-您需要将ref添加到参数中.
Hard to tell without seeing your declaration of UnsafeNativeMethods.IDispatch, but calling GetIDsOfNames without pinning the dispid array or adding a ref to the parameter is wrong. If you marshaled the array by passing the address by value the garbage collector could move the array around while the GetIDsOfNames call is still running and the native code would be writing to a wild pointer upon return. If you pass the array as a reference then your code won't compile - you need to add ref to the parameter.
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.此方法为您调用IDispatch::GetIDsOfNames和IDispatch::Invoke.
You can use System.Type.InvokeMember method to access global variables or functions via the script object. This method calls IDispatch::GetIDsOfNames and IDispatch::Invoke for you.
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