简介

COM is an acronym for Component Object Model; it is an object orientated layer (and associated services) on top of DCE RPC (an open standard) and defines a common calling convention that enables code written in any language to call and interoperate with code written in any other language (provided those languages are COM aware). Not only can the code be written in any language, but it need not even be part of the same executable; the code can be loaded from a DLL, be found in another process running on the same machine, or, with DCOM (Distributed COM), be found in another process on a remote machine, all without your code even needing to know where a component resides.

There is a subset of COM known as OLE Automation which comprises a set of COM interfaces that allow loose binding to COM objects, so that they can be introspected and called at run-time without compile-time knowledge of how the object works. The PHP COM extension utilizes the OLE Automation interfaces to allow you to create and call compatible objects from your scripts. Technically speaking, this should really be called the "OLE Automation Extension for PHP", since not all COM objects are OLE compatible.

Now, why would or should you use COM? COM is one of the main ways to glue applications and components together on the Windows platform; using COM you can launch Microsoft Word, fill in a document template and save the result as a Word document and send it to a visitor of your web site. You can also use COM to perform administrative tasks for your network and to configure your IIS; these are just the most common uses; you can do much more with COM.

Starting with PHP 5, this extension (and this documentation) was rewritten from scratch and much of the old confusing and bogus cruft has be removed. Additionally, we support the instantiation and creation of .Net assemblies using the COM interoperability layer provided by Microsoft.

Please read this article for an overview of the changes in this extension in PHP 5.

需求

COM functions are only available for the Windows version of PHP.

.Net support requires PHP 5 and the .Net runtime.

安装

本函数库作为 PHP 内核的一部分，不用安装就能使用。

PHP 的 Windows 版本已经内置该扩展模块的支持。无需加载任何附加扩展库即可使用这些函数。

You are responsible for installing support for the various COM objects that you intend to use (such as MS Word); we don't and can't bundle all of those with PHP.

For Each

Starting with PHP 5, you may use PHP's own the 节 called foreach 在 µÚ 16 章 statement to iterate over the contents of a standard COM/OLE IEnumVariant. In laymans terms, this means that you can use foreach in places where you would have used For Each in VB/ASP code.

例子 1. For Each in ASP <% Set domainObject = GetObject("WinNT://Domain") For Each obj in domainObject Response.Write obj.Name & "<br />" Next %>

例子 2. while() ... Next() in PHP 4 <?php $domainObject = new COM("WinNT://Domain"); while ($obj = $domainObject->Next()) {    echo $obj->Name . "<br />"; } ?>

例子 3. foreach in PHP 5 <?php $domainObject = new COM("WinNT://Domain"); foreach ($domainObject as $obj) {    echo $obj->Name . "<br />"; } ?>

Arrays and Array-style COM properties

Many COM objects expose their properties as arrays, or using array-style access. In PHP 4, you may use PHP array syntax to read/write such a property, but only a single dimension is allowed. If you want to read a multi-dimensional property, you could instead make the property access into a function call, with each parameter representing each dimension of the array access, but there is no way to write to such a property.

PHP 5 introduces the following new features to make your life easier:

• Access multi-dimensional arrays, or COM properties that require multiple parameters using PHP array syntax. You can also write or set properties using this technique.

• Iterate SafeArrays ("true" arrays) using the the 节 called foreach 在 µÚ 16 章 control structure. This works because SafeArrays include information about their size. If an array-style property implements IEnumVariant then you can also use foreach for that property too; take a look at the 节 called For Each for more information on this topic.

Exceptions (PHP 5)

This extension will throw instances of the class com_exception whenever there is a potentially fatal error reported by COM. All COM exceptions have a well-defined code property that corresponds to the HRESULT return value from the various COM operations. You may use this code to make programmatic decisions on how to handle the exception.

运行时配置

这些函数的行为受 php.ini 的影响。

以下是配置选项的简要解释。

预定义常量

以下常量由本扩展模块定义，因此只有在本扩展模块被编译到 PHP 中，或者在运行时被动态加载后才有效。

参见

For further information on COM read the COM specification or perhaps take a look at Don Box's Yet Another COM Library (YACL). You might find some additional useful information in our FAQ for µÚ 55 章. If you're thinking of using MS Office applications on the server side, you should read the information here: Considerations for Server-Side Automation of Office.