QNetworkRequest 类

QNetworkRequest class holds a request to be sent with QNetworkAccessManager . 更多...

头: #include <QNetworkRequest>
qmake: QT += network
Since: Qt 4.4

公共类型

enum 属性 { HttpStatusCodeAttribute, HttpReasonPhraseAttribute, RedirectionTargetAttribute, ConnectionEncryptedAttribute, ..., UserMax }
enum CacheLoadControl { AlwaysNetwork, PreferNetwork, PreferCache, AlwaysCache }
enum KnownHeaders { ContentDispositionHeader, ContentTypeHeader, ContentLengthHeader, LocationHeader, ..., ServerHeader }
enum LoadControl { Automatic, Manual }
enum Priority { HighPriority, NormalPriority, LowPriority }
enum RedirectPolicy { ManualRedirectPolicy, NoLessSafeRedirectPolicy, SameOriginRedirectPolicy, UserVerifiedRedirectPolicy }

公共函数

QNetworkRequest (const QUrl & url = QUrl())
QNetworkRequest (const QNetworkRequest & other )
~QNetworkRequest ()
QVariant attribute (QNetworkRequest::Attribute code , const QVariant & defaultValue = QVariant()) const
bool hasRawHeader (const QByteArray & headerName ) const
QVariant header (QNetworkRequest::KnownHeaders header ) const
int maximumRedirectsAllowed () const
QObject * originatingObject () const
QNetworkRequest::Priority priority () const
QByteArray rawHeader (const QByteArray & headerName ) const
QList<QByteArray> rawHeaderList () const
void setAttribute (QNetworkRequest::Attribute code , const QVariant & value )
void setHeader (QNetworkRequest::KnownHeaders header , const QVariant & value )
void setMaximumRedirectsAllowed (int maxRedirectsAllowed )
void setOriginatingObject (QObject * object )
void setPriority (QNetworkRequest::Priority priority )
void setRawHeader (const QByteArray & headerName , const QByteArray & headerValue )
void setSslConfiguration (const QSslConfiguration & config )
void setUrl (const QUrl & url )
QSslConfiguration sslConfiguration () const
void swap (QNetworkRequest & other )
QUrl url () const
bool operator!= (const QNetworkRequest & other ) const
QNetworkRequest & operator= (QNetworkRequest && other )
QNetworkRequest & operator= (const QNetworkRequest & other )
bool operator== (const QNetworkRequest & other ) const

详细描述

QNetworkRequest class holds a request to be sent with QNetworkAccessManager .

QNetworkRequest is part of the Network Access API and is the class holding the information necessary to send a request over the network. It contains a URL and some ancillary information that can be used to modify the request.

另请参阅 QNetworkReply and QNetworkAccessManager .

成员类型文档编制

enum QNetworkRequest:: 属性

属性代码用于 QNetworkRequest and QNetworkReply .

Attributes are extra meta-data that are used to control the behavior of the request and to pass further information from the reply back to the application. Attributes are also extensible, allowing custom implementations to pass custom values.

The following table explains what the default attribute codes are, the QVariant types associated, the default value if said attribute is missing and whether it's used in requests or replies.

常量 描述
QNetworkRequest::HttpStatusCodeAttribute 0 仅回复,类型: QMetaType::Int (no default) Indicates the HTTP status code received from the HTTP server (like 200, 304, 404, 401, etc.). If the connection was not HTTP-based, this attribute will not be present.
QNetworkRequest::HttpReasonPhraseAttribute 1 仅回复,类型: QMetaType::QByteArray (no default) Indicates the HTTP reason phrase as received from the HTTP server (like "Ok", "Found", "Not Found", "Access Denied", etc.) This is the human-readable representation of the status code (see above). If the connection was not HTTP-based, this attribute will not be present.
QNetworkRequest::RedirectionTargetAttribute 2 仅回复,类型: QMetaType::QUrl (no default) If present, it indicates that the server is redirecting the request to a different URL. The Network Access API does not by default follow redirections: the application can determine if the requested redirection should be allowed, according to its security policies, or it can set QNetworkRequest::FollowRedirectsAttribute to true (in which case the redirection will be followed and this attribute will not be present in the reply). The returned URL might be relative. Use QUrl::resolved () to create an absolute URL out of it.
QNetworkRequest::ConnectionEncryptedAttribute 3 仅回复,类型: QMetaType::Bool (default: false) Indicates whether the data was obtained through an encrypted (secure) connection.
QNetworkRequest::CacheLoadControlAttribute 4 仅请求,类型: QMetaType::Int (default: QNetworkRequest::PreferNetwork ) Controls how the cache should be accessed. The possible values are those of QNetworkRequest::CacheLoadControl . Note that the default QNetworkAccessManager implementation does not support caching. However, this attribute may be used by certain backends to modify their requests (for example, for caching proxies).
QNetworkRequest::CacheSaveControlAttribute 5 仅请求,类型: QMetaType::Bool (default: true) Controls if the data obtained should be saved to cache for future uses. If the value is false, the data obtained will not be automatically cached. If true, data may be cached, provided it is cacheable (what is cacheable depends on the protocol being used).
QNetworkRequest::SourceIsFromCacheAttribute 6 仅回复,类型: QMetaType::Bool (default: false) Indicates whether the data was obtained from cache or not.
QNetworkRequest::DoNotBufferUploadDataAttribute 7 仅请求,类型: QMetaType::Bool (default: false) Indicates whether the QNetworkAccessManager code is allowed to buffer the upload data, e.g. when doing a HTTP POST. When using this flag with sequential upload data, the ContentLengthHeader header must be set.
QNetworkRequest::HttpPipeliningAllowedAttribute 8 仅请求,类型: QMetaType::Bool (default: false) Indicates whether the QNetworkAccessManager code is allowed to use HTTP pipelining with this request.
QNetworkRequest::HttpPipeliningWasUsedAttribute 9 仅回复,类型: QMetaType::Bool Indicates whether the HTTP pipelining was used for receiving this reply.
QNetworkRequest::CustomVerbAttribute 10 仅请求,类型: QMetaType::QByteArray Holds the value for the custom HTTP verb to send (destined for usage of other verbs than GET, POST, PUT and DELETE). This verb is set when calling QNetworkAccessManager::sendCustomRequest ().
QNetworkRequest::CookieLoadControlAttribute 11 仅请求,类型: QMetaType::Int (default: QNetworkRequest::Automatic ) Indicates whether to send 'Cookie' headers in the request. This attribute is set to false by Qt WebKit when creating a cross-origin XMLHttpRequest where withCredentials has not been set explicitly to true by the Javascript that created the request. See here for more information. (This value was introduced in 4.7.)
QNetworkRequest::CookieSaveControlAttribute 13 仅请求,类型: QMetaType::Int (default: QNetworkRequest::Automatic ) Indicates whether to save 'Cookie' headers received from the server in reply to the request. This attribute is set to false by Qt WebKit when creating a cross-origin XMLHttpRequest where withCredentials has not been set explicitly to true by the Javascript that created the request. See here for more information. (This value was introduced in 4.7.)
QNetworkRequest::AuthenticationReuseAttribute 12 仅请求,类型: QMetaType::Int (default: QNetworkRequest::Automatic ) Indicates whether to use cached authorization credentials in the request, if available. If this is set to QNetworkRequest::Manual and the authentication mechanism is 'Basic' or 'Digest', Qt will not send an an 'Authorization' HTTP header with any cached credentials it may have for the request's URL. This attribute is set to QNetworkRequest::Manual by Qt WebKit when creating a cross-origin XMLHttpRequest where withCredentials has not been set explicitly to true by the Javascript that created the request. See here for more information. (This value was introduced in 4.7.)
QNetworkRequest::BackgroundRequestAttribute 17 类型: QMetaType::Bool (default: false) Indicates that this is a background transfer, rather than a user initiated transfer. Depending on the platform, background transfers may be subject to different policies. The QNetworkSession ConnectInBackground property will be set according to this attribute.
QNetworkRequest::SpdyAllowedAttribute 18 仅请求,类型: QMetaType::Bool (default: false) Indicates whether the QNetworkAccessManager code is allowed to use SPDY with this request. This applies only to SSL requests, and depends on the server supporting SPDY.
QNetworkRequest::SpdyWasUsedAttribute 19 仅回复,类型: QMetaType::Bool Indicates whether SPDY was used for receiving this reply.
QNetworkRequest::HTTP2AllowedAttribute 22 仅请求,类型: QMetaType::Bool (default: false) Indicates whether the QNetworkAccessManager code is allowed to use HTTP/2 with this request. This applies to SSL requests or 'cleartext' HTTP/2.
QNetworkRequest::HTTP2WasUsedAttribute 23 仅回复,类型: QMetaType::Bool (default: false) Indicates whether HTTP/2 was used for receiving this reply. (This value was introduced in 5.9.)
QNetworkRequest::EmitAllUploadProgressSignalsAttribute 20 仅请求,类型: QMetaType::Bool (default: false) Indicates whether all upload signals should be emitted. By default, the uploadProgress signal is emitted only in 100 millisecond intervals. (This value was introduced in 5.5.)
QNetworkRequest::FollowRedirectsAttribute 21 仅请求,类型: QMetaType::Bool (default: false) Indicates whether the Network Access API should automatically follow a HTTP redirect response or not. Currently redirects that are insecure, that is redirecting from "https" to "http" protocol, are not allowed. (This value was introduced in 5.6.)
QNetworkRequest::OriginalContentLengthAttribute 24 仅回复,类型 QMetaType::Int Holds the original content-length attribute before being invalidated and removed from the header when the data is compressed and the request was marked to be decompressed automatically. (This value was introduced in 5.9.)
QNetworkRequest::RedirectPolicyAttribute 25 仅请求,类型: QMetaType::Int , should be one of the QNetworkRequest::RedirectPolicy values (default: ManualRedirectPolicy ). This attribute obsoletes FollowRedirectsAttribute. (This value was introduced in 5.9.)
QNetworkRequest::Http2DirectAttribute 26 仅请求,类型: QMetaType::Bool (default: false) If set, this attribute will force QNetworkAccessManager to use HTTP/2 protocol without initial HTTP/2 protocol negotiation. Use of this attribute implies prior knowledge that a particular server supports HTTP/2. The attribute works with SSL or 'cleartext' HTTP/2. If a server turns out to not support HTTP/2, when HTTP/2 direct was specified, QNetworkAccessManager gives up, without attempting to fall back to HTTP/1.1. If both HTTP2AllowedAttribute and Http2DirectAttribute are set, Http2DirectAttribute takes priority. (This value was introduced in 5.11.)
QNetworkRequest::User 1000 Special type. Additional information can be passed in QVariants with types ranging from User to UserMax. The default implementation of Network Access will ignore any request attributes in this range and it will not produce any attributes in this range in replies. The range is reserved for extensions of QNetworkAccessManager .
QNetworkRequest::UserMax 32767 特殊类型。见 User。

该枚举在 Qt 4.7 引入或被修改。

enum QNetworkRequest:: CacheLoadControl

控制缓存机制为 QNetworkAccessManager .

常量 描述
QNetworkRequest::AlwaysNetwork 0 always load from network and do not check if the cache has a valid entry (similar to the "Reload" feature in browsers); in addition, force intermediate caches to re-validate.
QNetworkRequest::PreferNetwork 1 default value; load from the network if the cached entry is older than the network entry. This will never return stale data from the cache, but revalidate resources that have become stale.
QNetworkRequest::PreferCache 2 load from cache if available, otherwise load from network. Note that this can return possibly stale (but not expired) items from cache.
QNetworkRequest::AlwaysCache 3 仅从缓存加载,指示出错若项未缓存 (即:离线模式)

enum QNetworkRequest:: KnownHeaders

已知头类型列表 QNetworkRequest 剖析。每个已知头也以其完整 HTTP 名称按原生形式表示。

常量 描述
QNetworkRequest::ContentDispositionHeader 6 相当于 HTTP Content-Disposition 头且包含包含处置类型 (例如:附件) 及参数 (例如:文件名) 的字符串。
QNetworkRequest::ContentTypeHeader 0 相当于 HTTP Content-Type 头且包含包含媒体 MIME 类型及任何辅助数据 (例如:字符集) 的字符串。
QNetworkRequest::ContentLengthHeader 1 相当于 HTTP Content-Length 头且包含以字节为单位的传输数据长度。
QNetworkRequest::LocationHeader 2 相当于 HTTP Location 头且包含表示数据实际位置的 URL,包括重定向情况下的目的地 URL。
QNetworkRequest::LastModifiedHeader 3 相当于 HTTP Last-Modified 头且包含 QDateTime 表示内容的最后修改日期。
QNetworkRequest::IfModifiedSinceHeader 9 相当于 HTTP If-Modified-Since 头且包含 QDateTime 。它通常被添加到 QNetworkRequest 。服务器应发送 304 (未修改) 响应,若资源从此时间起未改变。
QNetworkRequest::ETagHeader 10 相当于 HTTP ETag 头且包含 QString 表示内容的最后修改状态。
QNetworkRequest::IfMatchHeader 11 相当于 HTTP If-Match 头且包含 QStringList 。它通常被添加到 QNetworkRequest 。服务器应发送 412 (前提条件失败) 响应,若资源不匹配。
QNetworkRequest::IfNoneMatchHeader 12 相当于 HTTP If-None-Match 头且包含 QStringList 。它通常被添加到 QNetworkRequest 。服务器应发送 304 (未修改) 响应,若资源匹配。
QNetworkRequest::CookieHeader 4 相当于 HTTP Cookie 头且包含 QList < QNetworkCookie > 表示要发送回服务器的 Cookie。
QNetworkRequest::SetCookieHeader 5 相当于 HTTP Set-Cookie 头且包含 QList < QNetworkCookie > 表示由服务器发送给本地存储的 Cookie。
QNetworkRequest::UserAgentHeader 7 由 HTTP 客户端发送的 User-Agent 头。
QNetworkRequest::ServerHeader 8 由 HTTP 客户端收到的服务器 Header 头。

另请参阅 header (), setHeader (), rawHeader (),和 setRawHeader ().

enum QNetworkRequest:: LoadControl

指示是否已手动覆盖请求的加载机制的某个方面,如,通过 Qt WebKit。

常量 描述
QNetworkRequest::Automatic 0 默认值:指示默认行为。
QNetworkRequest::Manual 1 指示行为已被手动覆盖。

该枚举在 Qt 4.7 引入或被修改。

enum QNetworkRequest:: Priority

此枚举列表可能的网络请求优先级。

常量 描述
QNetworkRequest::HighPriority 1 高优先级
QNetworkRequest::NormalPriority 3 正常优先级
QNetworkRequest::LowPriority 5 低优先级

该枚举在 Qt 4.7 引入或被修改。

enum QNetworkRequest:: RedirectPolicy

指示网络访问 API 是否应该自动遵循 HTTP 重定向响应。

常量 描述
QNetworkRequest::ManualRedirectPolicy 0 默认值:不遵循任何重定向。
QNetworkRequest::NoLessSafeRedirectPolicy 1 仅 http -> http、http -> https 或 https -> https 重定向被允许。相当于设置旧的 FollowRedirectsAttribute 为 true
QNetworkRequest::SameOriginRedirectPolicy 2 要求相同协议、主机及端口。注意:采用此策略 http://example.com 和 http://example.com:80 将失败 (隐式/明确端口被认为是不匹配的)。
QNetworkRequest::UserVerifiedRedirectPolicy 3 客户端决定是否遵循每个重定向通过处理 redirected() 信号,发射 redirectAllowed() 当 QNetworkReply 对象允许重定向或中止/完成以拒绝重定向。这可以被使用,例如,询问用户是否接受重定向,或基于某些特定 APP 配置来决定。

该枚举在 Qt 5.9 引入或被修改。

成员函数文档编制

QNetworkRequest:: QNetworkRequest (const QUrl & url = QUrl())

构造 QNetworkRequest 对象采用 url 作为要请求的 URL。

另请参阅 url () 和 setUrl ().

QNetworkRequest:: QNetworkRequest (const QNetworkRequest & other )

Creates a copy of other .

QNetworkRequest:: ~QNetworkRequest ()

Disposes of the QNetworkRequest 对象。

QVariant QNetworkRequest:: attribute ( QNetworkRequest::Attribute code , const QVariant & defaultValue = QVariant()) const

返回的属性关联代码 code . If the attribute has not been set, it returns defaultValue .

注意: 此函数不应用默认,列出于 QNetworkRequest::Attribute .

另请参阅 setAttribute () 和 QNetworkRequest::Attribute .

bool QNetworkRequest:: hasRawHeader (const QByteArray & headerName ) const

返回 true 若原生头 headerName 呈现在此网络请求中。

另请参阅 rawHeader () 和 setRawHeader ().

返回已知网络 Header 头的值为 header 若它呈现在此请求中。若不存在,返回 QVariant() (即:无效变体)。

另请参阅 KnownHeaders , rawHeader (),和 setHeader ().

int QNetworkRequest:: maximumRedirectsAllowed () const

Returns the maximum number of redirects allowed to be followed for this request.

该函数在 Qt 5.6 引入。

另请参阅 setMaximumRedirectsAllowed ().

QObject *QNetworkRequest:: originatingObject () const

Returns a reference to the object that initiated this network request; returns nullptr if not set or the object has been destroyed.

该函数在 Qt 4.6 引入。

另请参阅 setOriginatingObject ().

QNetworkRequest::Priority QNetworkRequest:: priority () const

返回此请求的优先级。

该函数在 Qt 4.7 引入。

另请参阅 setPriority ().

QByteArray QNetworkRequest:: rawHeader (const QByteArray & headerName ) const

返回 Header 头的原生形式为 headerName 。若不存在这种 Header 头,空 QByteArray 被返回,可能难以区分存在但没有内容的 Header 头 (使用 hasRawHeader () 以确定 Header 头是否存在)。

可以设置原生 Header 头采用 setRawHeader () 或采用 setHeader ().

另请参阅 header () 和 setRawHeader ().

QList < QByteArray > QNetworkRequest:: rawHeaderList () const

Returns a list of all raw headers that are set in this network request. The list is in the order that the headers were set.

另请参阅 hasRawHeader () 和 rawHeader ().

void QNetworkRequest:: setAttribute ( QNetworkRequest::Attribute code , const QVariant & value )

Sets the attribute associated with code code to be value value . If the attribute is already set, the previous value is discarded. In special, if value 是无效 QVariant , the attribute is unset.

另请参阅 attribute () 和 QNetworkRequest::Attribute .

void QNetworkRequest:: setHeader ( QNetworkRequest::KnownHeaders header , const QVariant & value )

Sets the value of the known header header value ,覆盖任何先前设置的 Header 头。此操作还设置等效原生 HTTP 头。

另请参阅 KnownHeaders , setRawHeader (),和 header ().

void QNetworkRequest:: setMaximumRedirectsAllowed ( int maxRedirectsAllowed )

Sets the maximum number of redirects allowed to be followed for this request to maxRedirectsAllowed .

该函数在 Qt 5.6 引入。

另请参阅 maximumRedirectsAllowed ().

void QNetworkRequest:: setOriginatingObject ( QObject * object )

Allows setting a reference to the object initiating the request.

For example Qt WebKit sets the originating object to the QWebFrame that initiated the request.

该函数在 Qt 4.6 引入。

另请参阅 originatingObject ().

void QNetworkRequest:: setPriority ( QNetworkRequest::Priority priority )

把此请求的优先级设为 priority .

注意: priority is only a hint to the network access manager. It can use it or not. Currently it is used for HTTP to decide which request should be sent first to a server.

该函数在 Qt 4.7 引入。

另请参阅 priority ().

void QNetworkRequest:: setRawHeader (const QByteArray & headerName , const QByteArray & headerValue )

设置 Header 头 headerName 到值 headerValue 。若 headerName 对应已知 Header 头 (见 QNetworkRequest::KnownHeaders ),原生格式将被剖析,相应 cooked 头也将被设置。

例如:

request.setRawHeader(QByteArray("Last-Modified"), QByteArray("Sun, 06 Nov 1994 08:49:37 GMT"));
					

还将设置已知 Header LastModifiedHeader to be the QDateTime 剖析日期对象。

注意: 设置相同的头 2 次覆盖先前设置。要完成相同名称多个 HTTP 头的行为,应采用逗号 , 分隔它们并串联这 2 个值,然后设置一个原生 Header 头。

另请参阅 KnownHeaders , setHeader (), hasRawHeader (),和 rawHeader ().

void QNetworkRequest:: setSslConfiguration (const QSslConfiguration & config )

Sets this network request's SSL configuration to be config . The settings that apply are the private key, the local certificate, the SSL protocol (SSLv2, SSLv3, TLSv1.0 where applicable), the CA certificates and the ciphers that the SSL backend is allowed to use.

另请参阅 sslConfiguration () 和 QSslConfiguration::defaultConfiguration ().

void QNetworkRequest:: setUrl (const QUrl & url )

Sets the URL this network request is referring to be url .

另请参阅 url ().

QSslConfiguration QNetworkRequest:: sslConfiguration () const

Returns this network request's SSL configuration. By default this is the same as QSslConfiguration::defaultConfiguration ().

另请参阅 setSslConfiguration () 和 QSslConfiguration::defaultConfiguration ().

void QNetworkRequest:: swap ( QNetworkRequest & other )

Swaps this network request with other 。此函数非常快,且从不失败。

该函数在 Qt 5.0 引入。

QUrl QNetworkRequest:: url () const

返回此网络请求所引用的 URL。

另请参阅 setUrl ().

bool QNetworkRequest:: operator!= (const QNetworkRequest & other ) const

返回 false if this object is not the same as other .

另请参阅 operator== ().

QNetworkRequest &QNetworkRequest:: operator= ( QNetworkRequest && other )

移动赋值运算符。

QNetworkRequest &QNetworkRequest:: operator= (const QNetworkRequest & other )

Creates a copy of other

bool QNetworkRequest:: operator== (const QNetworkRequest & other ) const

返回 true if this object is the same as other (i.e., if they have the same URL, same headers and same meta-data settings).

另请参阅 operator!= ().