QHostInfo ¶

概要 ¶

详细描述 ¶

QHostInfo finds the IP address(es) associated with a host name, or the host name associated with an IP address. The class provides two static convenience functions: one that works asynchronously and emits a signal once the host is found, and one that blocks and returns a QHostInfo 对象。

To look up a host’s IP addresses asynchronously, call lookupHost() , which takes the host name or IP address, a receiver object, and a slot signature as arguments and returns an ID. You can abort the lookup by calling abortHostLookup() with the lookup ID.

范例：

# To find the IP address of qt-project.org
QHostInfo.lookupHost("qt-project.org", self, SLOT("printResults(QHostInfo)"))
# To find the host name for 4.2.2.1
QHostInfo.lookupHost("4.2.2.1", self, SLOT("printResults(QHostInfo)"))
											

The slot is invoked when the results are ready. The results are stored in a QHostInfo object. Call addresses() to get the list of IP addresses for the host, and hostName() to get the host name that was looked up.

If the lookup failed, error() returns the type of error that occurred. errorString() gives a human-readable description of the lookup error.

若希望阻塞查找，使用 fromName() 函数：

info = QHostInfo.fromName("qt-project.org")
											

QHostInfo supports Internationalized Domain Names (IDNs) through the IDNA and Punycode standards.

To retrieve the name of the local host, use the static localHostName() 函数。

QHostInfo uses the mechanisms provided by the operating system to perform the lookup. As per { https://tools.ietf.org/html/rfc6724 }{RFC 6724} there is no guarantee that all IP addresses registered for a domain or host will be returned.

注意

Since Qt 4.6.1 QHostInfo is using multiple threads for DNS lookup instead of one dedicated DNS thread. This improves performance, but also changes the order of signal emissions when using lookupHost() compared to previous versions of Qt.

注意

Since Qt 4.6.3 QHostInfo is using a small internal 60 second DNS cache for performance improvements.

另请参阅

QAbstractSocket RFC 3492 RFC 6724

class QHostInfo ( d ) ¶

QHostInfo([lookupId=-1])

param lookupId

int

param d

QHostInfo

Constructs an empty host info object with lookup ID id .

另请参阅

lookupId()

PySide2.QtNetwork.QHostInfo. HostInfoError ¶

This enum describes the various errors that can occur when trying to resolve a host name.

常量	描述
QHostInfo.NoError	查找成功。
QHostInfo.HostNotFound	No IP addresses were found for the host.
QHostInfo.UnknownError	出现未知错误。

另请参阅

error() setError()

static PySide2.QtNetwork.QHostInfo. abortHostLookup ( lookupId ) ¶

参数

lookupId – int

Aborts the host lookup with the ID id , as returned by lookupHost() .

另请参阅

lookupHost() lookupId()

PySide2.QtNetwork.QHostInfo. addresses ( ) ¶

返回类型

Returns the list of IP addresses associated with hostName() . This list may be empty.

范例：

info = QHostInfo()
...
if not info.addresses().isEmpty():
    address = info.addresses().first()
    # use the first IP address
											

另请参阅

setAddresses() hostName() error()

PySide2.QtNetwork.QHostInfo. error ( ) ¶

返回类型

HostInfoError

Returns the type of error that occurred if the host name lookup failed; otherwise returns NoError .

另请参阅

setError() errorString()

PySide2.QtNetwork.QHostInfo. errorString ( ) ¶

返回类型

unicode

If the lookup failed, this function returns a human readable description of the error; otherwise “Unknown error” is returned.

另请参阅

setErrorString() error()

static PySide2.QtNetwork.QHostInfo. fromName ( name ) ¶

参数

name – unicode

返回类型

QHostInfo

Looks up the IP address(es) for the given host name . The function blocks during the lookup which means that execution of the program is suspended until the results of the lookup are ready. Returns the result of the lookup in a QHostInfo 对象。

If you pass a literal IP address to name instead of a host name, QHostInfo will search for the domain name for the IP (i.e., QHostInfo will perform a reverse lookup). On success, the returned QHostInfo will contain both the resolved domain name and IP addresses for the host name.

另请参阅

lookupHost()

PySide2.QtNetwork.QHostInfo. hostName ( ) ¶

返回类型

unicode

Returns the name of the host whose IP addresses were looked up.

另请参阅

setHostName() localHostName()

static PySide2.QtNetwork.QHostInfo. localDomainName ( ) ¶

返回类型

unicode

Returns the DNS domain of this machine.

注意

DNS domains are not related to domain names found in Windows networks.

另请参阅

hostName()

static PySide2.QtNetwork.QHostInfo. localHostName ( ) ¶

返回类型

unicode

Returns this machine’s host name, if one is configured. Note that hostnames are not guaranteed to be globally unique, especially if they were configured automatically.

This function does not guarantee the returned host name is a Fully Qualified Domain Name (FQDN). For that, use fromName() to resolve the returned name to an FQDN.

This function returns the same as machineHostName() .

另请参阅

hostName() localDomainName()

PySide2.QtNetwork.QHostInfo. lookupId ( ) ¶

返回类型

int

Returns the ID of this lookup.

另请参阅

setLookupId() abortHostLookup() hostName()

PySide2.QtNetwork.QHostInfo. setAddresses ( addresses ) ¶

参数

addresses –

Sets the list of addresses in this QHostInfo to addresses .

另请参阅

addresses()

PySide2.QtNetwork.QHostInfo. setError ( error ) ¶

参数

error – HostInfoError

Sets the error type of this QHostInfo to error .

另请参阅

error() errorString()

PySide2.QtNetwork.QHostInfo. setErrorString ( errorString ) ¶

参数

errorString – unicode

Sets the human readable description of the error that occurred to str if the lookup failed.

另请参阅

errorString() setError()

PySide2.QtNetwork.QHostInfo. setHostName ( name ) ¶

参数

name – unicode

Sets the host name of this QHostInfo to hostName .

另请参阅

hostName()

PySide2.QtNetwork.QHostInfo. setLookupId ( id ) ¶

参数

id – int

Sets the ID of this lookup to id .

另请参阅

lookupId() lookupHost()

PySide2.QtNetwork.QHostInfo. swap ( other ) ¶

参数

other – QHostInfo

Swaps host-info other with this host-info. This operation is very fast and never fails.