.NET mshtml：如何传递BSTR SAFEARRAY？ [英] .NET mshtml: How to pass a BSTR SAFEARRAY?
问题描述
Microsoft.mshtml.dll程序集中的类mshtml.HTMLDocumentClass有一个方法：
The class mshtml.HTMLDocumentClass in Microsoft.mshtml.dll assembly has a method:
public virtual void write(params object[] psarray);
避免真正的问题，你会用什么代码调用 write ？您会使用：
Avoiding the real question for a moment, what code would you use to call write()? Would you use:
String html = "<html><body>Hello, world!</body></html>";
mshtml.HTMLDocumentClass doc;
...
doc.write(html);
或您将使用：
String html = "<html><body>Hello, world!</body></html>";
mshtml.HTMLDocumentClass doc;
...
object[] params = new Object[1];
params[0] = html;
doc.write(params);
因为这两个都抛出异常。 （type mismatch。0x80020005）
Because both of those throw an exception. (Type mismatch. 0x80020005)
HTMLDocumentClass.write 方法实际上来自 IHTMLDocument2接口，其记录为：
The HTMLDocumentClass.write method actually comes from IHTMLDocument2 interface, which is documented as:
IHTMLDocument2 :: write方法
IHTMLDocument2::write Method
在指定窗口中将一个或多个HTML表达式写入
文档。
Writes one or more HTML expressions to a document in the specified window.
语法
HRESULT write(
SAFEARRAY *psarray
);
参数
psarray
[in] A **BSTR** that specifies the text and HTML tags to write.
所以在现实中写方法需要一个指向SAFEARRAY的指针，即使Microsoft的 Microsoft.mshtml 互操作程序集将写方法定义为使用常规数组：
So in reality the write method needs a pointer to a SAFEARRAY, even though Microsoft's Microsoft.mshtml interop assembly define the write method as taking a regular array:
public virtual void write(params object[] psarray);
忽略mshtml interop声明，我必须构造一个 SAFEARRAY 对象对于一个对象数组），用一个BSTR字符串（对于一个字符串）填充它，并将其填充到一个必须是对象数组的参数。
Ignoring the mshtml interop declaration, i have to construct a SAFEARRAY object (verses an object array), fill it with a BSTR string (verses a String), and stuff it into a parameter that must be an object array.
注意：我不确定 params 关键字的含义。它用于指示可变数量的参数。
Note: i'm unsure of the meaning of the params keyword. It is used to indicate a variable number of parameters.
这是否意味着它可以接受多个数组参数？
Does that mean that it can take multiple array parameters?
object[] array1 = new Object[1];
array1 [0] = alpha;
object[] array2 = new Object[1];
array2 [0] = bravo;
object[] array3 = new Object[1];
array3 [0] = charlie;
object[] array4 = new Object[1];
array4 [0] = delta;
doc.write(array1, array2, array3, array4);
或者是object []传递多个参数的方法，你必须逐字地创建一个数组？
Or is object[] the method in which multiple parameters are passed, and you must literally create an array?
object[] params = new Object[4];
params[0] = alpha;
params[1] = bravo;
params[2] = charlie;
params[3] = delta;
doc.write(params);
或者数组[]只是一个诱饵，你真的可以通过：
Or is the array[] just a decoy, and really you pass:
doc.write(alpha, bravo, charlie, delta);
当我最初使用这个代码时， Win32应用程序，BSTR被放置在一个SAFEARRAY。在基于IDispatch的自动化中，一切都在数组内。在这种情况下，后期绑定代码：
When i originally used this code, from a native Win32 app, the BSTR was placed inside a SAFEARRAY. In IDispatch based automation, everything is inside an array. In this case the late binding code:
doc.write(html);
转换为SAFEARRAY，其中第零个元素包含一个BSTR字符串是一个长度前缀的unicode字符串）。
was converted by the compiler into a SAFEARRAY, where the zero-th element contains a BSTR string (which is a length prefixed unicode string).
我的问题成为一个尝试构造一个SAFEARRAY，将一个字符串转换为BSTR，将BSTR放置到第零元素的SAFEARRAY，并将包含SAFEARRAY的变量传递给只接受对象数组（object []）的变量。
My problem becomes one of trying to construct a SAFEARRAY, converting a String into a BSTR, placing the BSTR into the zero-th element of the SAFEARRAY, and passing a variable that contains a SAFEARRAY to one that only accepts an object array (object[]).
这是真正的问题： 如何创建BSTR SAFEARRAY？
This is the real question: how to create a BSTR SAFEARRAY?
Microsoft.mshtml
Microsoft.mshtml
C：\Program
Files \Microsoft.NET \Primary Interop
Assemblies\Microsoft.mshtml.dll
C:\Program Files\Microsoft.NET\Primary Interop Assemblies\Microsoft.mshtml.dll
推荐答案
IHTMLDocument2 由TLBIMP / VS.NET创建的界面是不正确的。它应该是：
The declaration for the write method on the IHTMLDocument2 interface created by TLBIMP/VS.NET is incorrect. It should be:
void Write([In, MarshalAs(UnmanagedType.SafeArray)] object[] psarray);
您必须在代码中定义此接口，然后使用。
You will have to define this interface in code and then use that.
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