从Unicode创建CData节点时XML无效字符 ID:NaveCabro XE5C++ +Builder。< /P>
我正试图在XMLCDATA部分中转储Unicode解压 这种字符串的小摘录：从Unicode创建CData节点时XML无效字符 ID:NaveCabro XE5C++ +Builder。< /P>,c++,xml,c++builder,C++,Xml,C++builder,我正试图在XMLCDATA部分中转储Unicode解压 这种字符串的小摘录： u"‰PNG\r\n\x1A\n\0\0\0\rIHDR\0\0\0õ\0\0\02\b\x06\0\0\0„\\i\0\0\0\x01sRGB\0®Î\x1Cé\0\0\0\x04gAMA\0\0±\vüa\x05\0\0\0\tpHYs\0\0\x0EÃ\0\0\x0EÃ\x01Ço¨d\0\0\v¼IDATxÚíœypUÕ\x19ÀO\x06…°¤\x04D$ˆ²\b1š\b\x18@...etc" 我知道X
u"‰PNG\r\n\x1A\n\0\0\0\rIHDR\0\0\0õ\0\0\02\b\x06\0\0\0„\\i\0\0\0\x01sRGB\0®Î\x1Cé\0\0\0\x04gAMA\0\0±\vüa\x05\0\0\0\tpHYs\0\0\x0EÃ\0\0\x0EÃ\x01Ço¨d\0\0\v¼IDATxÚíœypUÕ\x19ÀO\x06…°¤\x04D$ˆ²\b1š\b\x18@...etc"
_di_IXMLDocument pXMLDocument = NewXMLDocument("1.0");
// I've played around with the document encoding with no success, guessing it's only applicable while reading the document.
// pXMLDocument->SetEncoding(L"iso-8859-1");
String myString; // Unicode, contains my data string.
// 1st param of CreateNode method is of type UnicodeString.
di_IXMLNode pCDataNode = pXMLDocument->CreateNode( myString, ntCData );
有没有想过为什么会失败？编码问题？事实证明，问题确实是原始数据字符串中存在的所有转义字符，正如所怀疑的那样 通过在创建XML CData节之前对整个字符串进行Base64编码，解决了这个问题 Rad Studio方法：EncodeBase64，DecodeBase64 标题：Soap.EncdDecd.hpp如果您阅读了，它描述了CDATA节的格式：
CDATA Sections
[18] CDSect ::= CDStart CData CDEnd
[19] CDStart ::= '<![CDATA['
[20] CData ::= (Char* - (Char* ']]>' Char*))
[21] CDEnd ::= ']]>'
CDATA节不授予您将任意二进制数据放入XML数据的权限。当文本内容包含通常为XML标记保留的字符时，可以使用CDATA节，这样它们就不必转义或作为实体编码。将二进制数据放入XML文档的唯一方法是使用与XML兼容（通常为7bit ASCII）格式，如Base64（但也有其他可用格式，如yEnc）。针对我的情况，我创建了一个函数，将字符串修剪为一组有效的XML字符 伪代码：
//Code released into public domain. No attribution required.
function TrimToXmlText(xmlText: String): string;
begin
/*
http://www.w3.org/TR/xml/#NT-Char
Regarless of entity encoding, the only valid characters allowed are:
Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]
I.e. any Unicode character, excluding the surrogate blocks, FFFE, and FFFF.
This means that a string such as
"Line one"#31#10"Line two"
is invalid (because of the #31 aka 0x1F).
This means we need to manually strip them out; because the xml library certainly won't do it for us.
*/
SetLength(Result, Length(xmlText));
Int32 o = 0;
for i = 1 to Length(s) do
begin
case Ord(s[i]) of
$9, $A, $D,
$20..$D7FF,
$E000..$FFFD:
begin
o = o+1;
Result[o] = xmlText[i];
end;
end;
end;
SetLength(Result, o);
end;
看起来问题实际上可能是字符串的内容。由于数据的“随机”性质，字符串包含大量的字符文字（转义字符）…并且它们是错误的（根据我的要求）这样解释。会导致问题。因此，在创建CData节点之前，需要对数据字符串进行转义字符分析。
//Code released into public domain. No attribution required.
function TrimToXmlText(xmlText: String): string;
begin
/*
http://www.w3.org/TR/xml/#NT-Char
Regarless of entity encoding, the only valid characters allowed are:
Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF]
I.e. any Unicode character, excluding the surrogate blocks, FFFE, and FFFF.
This means that a string such as
"Line one"#31#10"Line two"
is invalid (because of the #31 aka 0x1F).
This means we need to manually strip them out; because the xml library certainly won't do it for us.
*/
SetLength(Result, Length(xmlText));
Int32 o = 0;
for i = 1 to Length(s) do
begin
case Ord(s[i]) of
$9, $A, $D,
$20..$D7FF,
$E000..$FFFD:
begin
o = o+1;
Result[o] = xmlText[i];
end;
end;
end;
SetLength(Result, o);
end;