Question

我正在使用XmlLite库来创建XML文件。我希望生成的XML文件的序言不包含编码属性（只是版本）：

<?xml version="1.0"?>

这是我的代码：

    HRESULT hr = S_OK;
    IStream *pOutFileStream = NULL;
    IXmlWriter *pWriter = NULL;
    CComPtr<IXmlWriterOutput> pWriterOutput;

    //Open writeable output stream
    if (FAILED(hr = SHCreateStreamOnFile(output_file_name, STGM_CREATE | STGM_WRITE, &pOutFileStream)))
    {
        wprintf(L"Error creating file writer, error is %08.8lx", hr);
        HR(hr);
    }

    if (FAILED(hr = CreateXmlWriter(__uuidof(IXmlWriter), (void**) &pWriter, NULL)))
    {
        wprintf(L"Error creating xml writer, error is %08.8lx", hr);
        HR(hr);
    }

    if(FAILED(CreateXmlWriterOutputWithEncodingName(pOutFileStream, NULL, L"UTF-8", &pWriterOutput))){
        wprintf(L"Error setting xml encoding, error is %08.8lx", hr);
        HR(hr);
    }

    if (FAILED(hr = pWriter->SetOutput(pWriterOutput)))
    {
        wprintf(L"Error, Method: SetOutput, error is %08.8lx", hr);
        HR(hr);
    }

    if (FAILED(hr = pWriter->SetProperty(XmlWriterProperty_Indent, 4)))
    {
        wprintf(L"Error, Method: SetProperty XmlWriterProperty_Indent, error is %08.8lx", hr);
        HR(hr);
    }

    if (FAILED(hr = pWriter->WriteStartDocument(XmlStandalone_Omit)))
    {
        wprintf(L"Error, Method: WriteStartDocument, error is %08.8lx", hr);
        HR(hr);
    }

我已尝试删除对CreateXmlWriterOutputWithEncodingName()的调用，但即使这样，也会创建一个包含UTF-8的默认编码属性。我也尝试将NULL作为该函数的第三个参数。

非常感谢协助！

Answer 1

XML声明由WriteStartDocument method编写。

您可以使用WriteStartDocument作为处理指令的名称来调用WriteProcessingInstruction，而不是调用L"xml"，以便按照您希望的方式编写XML声明，例如：

if (FAILED(hr = pWriter->WriteProcessingInstruction(L"xml", L"version=\"1.0\"")))
{
    wprintf(L"Error, Method: WriteProcessingInstruction, error is %08.8lx", hr); 
    HR(hr); 
}

这会将XML声明写为<?xml version="1.0"?>。

使用XmlLite IXmlWriter（C ++）在prolog中创建没有编码属性的XML

1 个答案: