.NET MSHTML：如何通过一个BSTR SAFEARRAY？ [英] .NET mshtml: How to pass a BSTR SAFEARRAY?
问题描述
在Microsoft.mshtml.dll组件的类mshtml.HTMLDocumentClass有一个方法：
公共虚拟无效写入（params对象[] psarray）;
避免真正的问题了一会儿，你会用什么code调用的write（）？你会使用：
字符串的HTML =＆LT; HTML＆GT;＆LT;身体GT;您好，世界＆LT; / BODY＆GT;＆LT; / HTML＆gt;中;
mshtml.HTMLDocumentClass文档;
...
doc.write（HTML）;
或你会使用：
字符串的HTML =＆LT; HTML＆GT;＆LT;身体GT;您好，世界＆LT; / BODY＆GT;＆LT; / HTML＆gt;中;
mshtml.HTMLDocumentClass文档;
...
[对象] PARAMS =新的对象[1];
PARAMS [0] =的html;
doc.write（PARAMS）;
由于这两个抛出异常。 （类型不匹配。0x80020005）
在 HTMLDocumentClass.write 方式实际上来自的的IHTMLDocument2接口，其记录为：
的IHTMLDocument2 :: Write方法
写入一个或多个HTML EX pressions到 在指定的窗口的文档。
语法
HRESULT写（ SAFEARRAY * psarray ）;
参数
psarray
[中] A ** ** BSTR指定的文本和HTML标记来写。
因此，在现实中写方法需要一个指向一个SAFEARRAY，即使微软的 Microsoft.mshtml 互操作程序集定义的写方法，采取定期的数组：
公共虚拟无效写入（params对象[] psarray）;
忽略MSHTML互操作的声明，我要建立一个 SAFEARRAY 的对象（诗的对象数组），有一个BSTR字符串（诗一字符串）填充它，和东西到一个参数是必须是一个对象数组。
注：我不能确定的 PARAMS 关键字的含义。它用于指示可变数量的参数。
这是否意味着它可以多个数组参数？
[对象] ARRAY1 =新的对象[1];
ARRAY1 [0] =阿尔法;
[对象] ARRAY2 =新的对象[1];
ARRAY2 [0] =喝彩;
[对象] ARRAY3 =新的对象[1];
ARRAY3 [0] =查理;
[对象] array4 =新的对象[1];
array4 [0] =增量;
doc.write（ARRAY1，ARRAY2，ARRAY3，array4）;
或者是Object []的方法，其中多个参数传递，你必须从字面上创建一个数组？
[对象] PARAMS =新的对象[4]。
PARAMS [0] =阿尔法;
PARAMS [1] =喝彩;
PARAMS [2] =查理;
PARAMS [3] =增量;
doc.write（PARAMS）;
或者是数组[]只是一个诱饵，真正传递：
doc.write（α，布拉沃，查理，三角洲）;
当我最初使用这个code，从本机Win32应用程序，该BSTR被放置在一个SAFEARRAY。在IDispatch的基础自动化，一切都是一个数组中。在这种情况下，后期绑定code：
doc.write（HTML）;
转化由编译成一个SAFEARRAY，其中零个元素包含一个BSTR字符串（这是一个长度prefixed单向code字符串）。
我的问题成为试图构建一个SAFEARRAY，将字符串转换成BSTR，放置BSTR到SAFEARRAY的零个元素，并通过包含一个SAFEARRAY一个变量只接受一个对象阵列中的一个（对象[]）。
这是真正的问题：如何创建一个BSTR SAFEARRAY
Microsoft.mshtml
C：\ PROGRAM 文件\ Microsoft.NET \ Primary互操作程序 大会\ Microsoft.mshtml.dll
的声明上的 的IHTMLDocument2 通过TLBIMP创建的接口/ VS.NET不正确。它应该是：
无效写（[中，的MarshalAs（UnmanagedType.SafeArray）] [对象] psarray）;
您必须定义在code此接口，然后使用它。
The class mshtml.HTMLDocumentClass in Microsoft.mshtml.dll assembly has a method:
public virtual void write(params object[] psarray);
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);
or would you use:
String html = "<html><body>Hello, world!</body></html>";
mshtml.HTMLDocumentClass doc;
...
object[] params = new Object[1];
params[0] = html;
doc.write(params);
Because both of those throw an exception. (Type mismatch. 0x80020005)
The HTMLDocumentClass.write method actually comes from IHTMLDocument2 interface, which is documented as:
IHTMLDocument2::write Method
Writes one or more HTML expressions to a document in the specified window.
Syntax
HRESULT write( SAFEARRAY *psarray );Parameters
psarray
[in] A **BSTR** that specifies the text and HTML tags to write.
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);
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.
Note: i'm unsure of the meaning of the params keyword. It is used to indicate a variable number of parameters.
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);
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);
Or is the array[] just a decoy, and really you pass:
doc.write(alpha, bravo, charlie, delta);
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);
was converted by the compiler into a SAFEARRAY, where the zero-th element contains a BSTR string (which is a length prefixed unicode string).
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[]).
This is the real question: how to create a BSTR SAFEARRAY?
Microsoft.mshtml
C:\Program Files\Microsoft.NET\Primary Interop Assemblies\Microsoft.mshtml.dll
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);
You will have to define this interface in code and then use that.
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