Com 从'；长'；至'；VARTYPE'；，数据可能丢失

在将VC++6.0开发的代码迁移到Visual studio 2008时，我收到了以下警告

警告C4244:“=”：从“long”转换为“VARTYPE”，可能会丢失数据

代码段：

STDMETHODIMP CTextFileParser::FormatString(long lTargetType, BSTR szFormat, BSTR      szInput, VARIANT *value) // Has Definition of lTargetType
CComVariant vErg(szSource.c_str()); // Definition of vErg
vErg.vt = lTargetType; // C4244

STDMETHODIMP CField::get_ContentWithType(long lType, VARIANT *pVal) // Has Definition of lType
{
 HRESULT hRC;
 CComVariant oNewValue(m_content);           // Definition of oNewValue
 hRC = oNewValue.ChangeType(lType, NULL);    // C4244
 if (SUCCEEDED(hRC)) oNewValue.Detach(pVal);
 return hRC;
}

警告C4244:“参数”：从“long”转换为“VARTYPE”，可能会丢失数据

代码段：

STDMETHODIMP CTextFileParser::FormatString(long lTargetType, BSTR szFormat, BSTR      szInput, VARIANT *value) // Has Definition of lTargetType
CComVariant vErg(szSource.c_str()); // Definition of vErg
vErg.vt = lTargetType; // C4244

STDMETHODIMP CField::get_ContentWithType(long lType, VARIANT *pVal) // Has Definition of lType
{
 HRESULT hRC;
 CComVariant oNewValue(m_content);           // Definition of oNewValue
 hRC = oNewValue.ChangeType(lType, NULL);    // C4244
 if (SUCCEEDED(hRC)) oNewValue.Detach(pVal);
 return hRC;
}

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我无法修复此警告？。

VARTYPE是一种16位整数类型：

WTYPES.H:typedef unsigned short VARTYPE;

您将需要一个

static\u cast（）