Delphi的SOAP Header问题

对于我的程序，服务器要求的Header是这样(只是要添加两个简单的元素):

BigLuo
111

但Delphi中的SOAPHeader只能通过继承TSOAPHeader来实现，但这样就会把派生类的名字添加上去，变成了这样:

4
2005-01-06T15:01:26.531Z

怎么办?

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1.Delphi给了一个SOAP Header的示例

4
2005-01-06T15:01:26.531Z

实现方法是:
1.先定义一个TSOAPHeader的继承类，要在SOAP包中出现的字段以property方式出现

AuthHeader = class(TSOAPHeader)
private
FAccNumber: Integer;
FTimeStamp: TXSDateTime;
public
destructor Destroy; override; //用于释放FTimeStamp，别无它用
published
property AccNumber: Integer read FAccNumber write FAccNumber;
property TimeStamp: TXSDateTime read FTimeStamp write FTimeStamp;
end;

2.在initialization中注册

InvRegistry.RegisterHeaderClass(TypeInfo(IBankAccount), AuthHeader, 'AuthHeader', 'urn:BankAccountIntf');
RemClassRegistry.RegisterXSClass(AuthHeader, 'urn:BankAccountIntf', 'AuthHeader');

3.使用:

var
H: AuthHeader;
svc: IBankAccount;
begin
svc := HTTPRIO1 as IBankAccount;

H := AuthHeader.Create;
try
H.AccNumber := FAuthKey;
H.TimeStamp := DateTimeToXSDateTime(FTimeStamp, True);
if UseHeader then
(svc as ISOAPHeaders).send(H);
svc.some_method(...)
finally
H.Free;
end

2. 我的要求和问题
对于我的程序，服务器要求的Header是这样

BigLuo
111

与上面的不同是Header下直接是两个元素，没有一个NS1:AuthHeader的外包层

仔细查看了一下Delphi的帮助，在Defining and using SOAP headers一节淘到如下一段

Handling scalar-type headers

Some Web Services define and use headers that are simple types (such as an integer or string) rather than a complex structure that corresponds to a remotable type. However, Delphi's support for SOAP headers requires that you use a TSOAPHeader descendant to represent header types. You can define header classes for simple types by treating the TSOAPHeader class as a holder class. That is, the TSOAPHeader descendant has a single published property, which is the type of the actual header. To signal that the SOAP representation does not need to include a node for the TSOAPHeader descendant, call the remotable type registry's RegisterSerializeOptions method (after registering the header type) and give your header type an option of xoSimpleTypeWrapper.

从最后一句看，我只要这样定义:

HdrUsername = class(TSOAPHeader)
private
FUsername: String;
published
property Username: String read FUsername write FUsername;
end;

然后按如下方式注册

InvRegistry.RegisterHeaderClass(TypeInfo(ezMsgServer), HdrUsername, 'Username', ');
RemClassRegistry.RegisterSerializeOptions(TypeInfo(HdrUsername), [xoSimpleTypeWrapper]);

(Password一项也类似处理)
应该就可以了。

但运行一下发现文档里面说的根本就不对，而是这样:

y19451


mypass

看样子xoSimpleTypeWrapper根本没有任何作用(不加那一句也是这个结果)

3. 问题的解决

在帮助文件里面来回折腾了半天，看到RegisterSerializeOptions的帮助里提到这样一个选项

xoHolderClass
The remotable object corresponds to a "holder" class. That is, the SOAP representation does not include a node for the class itself, just for its members. This is used when a type that would otherwise not require a remotable class uses a feature only available on remotable classes (such as attributes).

这个选项倒好像跟我的需求比较接近哦，试试！
结果又是失望。“希望，失望，希望，失望”，麦兜抱怨到。

在google上搜索了半天没有发现什么有用的结果，在无望之余回来又来看Delphi提供的例子，注意到它的例子中将AuthHeader这个类注册了一下:

RemClassRegistry.RegisterXSClass(AuthHeader, 'urn:BankAccountIntf', 'AuthHeader');

对啊，这个类应该在Remote Class Registry里面注册，于是加上HdrUsername和HdrPassword的注册语句, 再试，搞定!

总结一下:
帮助里面说的应该是纯常量作为Header的情况，对于我这种......的情况，应该按如下方式处理:
1. 按上面所说，声明HdrUsername和HdrPassword
2. 在initialization时按如下方式注册

InvRegistry.RegisterHeaderClass(TypeInfo(ezMsgServer), HdrUsername, 'Username', ');
RemClassRegistry.RegisterXSClass(HdrUsername, ', 'Username', 'Username');
RemClassRegistry.RegisterSerializeOptions(TypeInfo(HdrUsername), [xoHolderClass]);

InvRegistry.RegisterHeaderClass(TypeInfo(ezMsgServer), HdrPassword, 'Password', ');
RemClassRegistry.RegisterXSClass(HdrPassword, ', 'Password', 'Password');
RemClassRegistry.RegisterSerializeOptions(HdrPassword, [xoHolderClass]);

其实这样也可以(而且简单一点):
1. 将Username和Password声明在一个Header内
以下内容为程序代码:

TezMsgHdr = class(TSOAPHeader)
private
FUsername: String;
FPassword: String;
published
property Username: String read FUsername write FUsername;
property Password: String read FPassword write FPassword;
end;

2.将TMsgHdr注册:

InvRegistry.RegisterHeaderClass(TypeInfo(ezMsgServer), TezMsgHdr, 'Username', ', hmtRequest);
RemClassRegistry.RegisterXSInfo(TypeInfo(TezMsgHdr), ', 'Username', 'Username');
RemClassRegistry.RegisterSerializeOptions(TypeInfo(TezMsgHdr), [xoSimpleTypeWrapper, xoHolderClass]);

总的来说，还是看E文水平不够啊

4. 其他

细心的话，可以注意到后面一种方法里面多了一个xoSimpleTypeWrapper选项。其实对于后一种方法的复杂类TezMsgHdr, 这个选项是无效的，但对于前一种，就有些不同了(正如其名称所表明的那样，只有真正是SimpleType才有作用):

a. 如果只对HdrUsername加xoSimpleTypeWrapper选项:

y19451Password

可以注意到Username元素不见了，只能见到其值y19451赤裸地出现，而Password一项正常

b.如果只对HdrPassword加xoSimpleTypeWrapper选项:
运行时会出现"Element does not contain a single text node"这样的错误。我估计SOAP Header如下，Password的出现导致了这不是一个合法的XML

y19451Password

c.如果两者都加xoSimpleTypeWrapper选项，结果会是怎样呢?

Password

居然Username都不见了