System::Net::HttpKnownHeaderNames::IfUnmodifiedSince 字段。

IfUnmodifiedSince field

该 ‘If-Unmodified-Since’ 头部名称。

static const String System::Net::HttpKnownHeaderNames::IfUnmodifiedSince

另见

System::Net::HttpKnownHeaderNames::IfRange 字段 System::Net::HttpKnownHeaderNames::KeepAlive 字段。