PySide.QtNetwork.QHttp class provides an implementation of the HTTP protocol.
This class provides a direct interface to HTTP that allows you to download and upload data with the HTTP protocol. However, for new applications, it is recommended to use PySide.QtNetwork.QNetworkAccessManager and PySide.QtNetwork.QNetworkReply , as those classes possess a simpler, yet more powerful API and a more modern protocol implementation.
The class works asynchronously, so there are no blocking functions. If an operation cannot be executed immediately, the function will still return straight away and the operation will be scheduled for later execution. The results of scheduled operations are reported via signals. This approach depends on the event loop being in operation.
The operations that can be scheduled (they are called “requests” in the rest of the documentation) are the following: PySide.QtNetwork.QHttp.setHost() , PySide.QtNetwork.QHttp.get() , PySide.QtNetwork.QHttp.post() , PySide.QtNetwork.QHttp.head() and PySide.QtNetwork.QHttp.request() .
All of these requests return a unique identifier that allows you to keep track of the request that is currently executed. When the execution of a request starts, the PySide.QtNetwork.QHttp.requestStarted() signal with the identifier is emitted and when the request is finished, the PySide.QtNetwork.QHttp.requestFinished() signal is emitted with the identifier and a bool that indicates if the request finished with an error.
To make an HTTP request you must set up suitable HTTP headers. The following example demonstrates how to request the main HTML page from the Qt website (i.e., the URL http://qt.nokia.com/index.html ):
header = QHttpRequestHeader("GET", QUrl.toPercentEncoding("/index.html"))
header.setValue("Host", "qtsoftware.com")
http.setHost("qtsoftware.com")
http.request(header)
For the common HTTP requests GET , POST and HEAD , PySide.QtNetwork.QHttp provides the convenience functions PySide.QtNetwork.QHttp.get() , PySide.QtNetwork.QHttp.post() and PySide.QtNetwork.QHttp.head() . They already use a reasonable header and if you don't have to set special header fields, they are easier to use. The above example can also be written as:
http.setHost("qtsoftware.com") # id == 1
http.get(QUrl.toPercentEncoding("/index.html")) # id == 2
For this example the following sequence of signals is emitted (with small variations, depending on network traffic, etc.):
requestStarted(1)
requestFinished(1, False)
requestStarted(2)
stateChanged(Connecting)
stateChanged(Sending)
dataSendProgress(77, 77)
stateChanged(Reading)
responseHeaderReceived(responseheader)
dataReadProgress(5388, 0)
readyRead(responseheader)
dataReadProgress(18300, 0)
readyRead(responseheader)
stateChanged(Connected)
requestFinished(2, False)
done(False)
stateChanged(Closing)
stateChanged(Unconnected)
PySide.QtNetwork.QHttp.dataSendProgress() and PySide.QtNetwork.QHttp.dataReadProgress() signals in the above example are useful if you want to show a progress bar to inform the user about the progress of the download. The second argument is the total size of data. In certain cases it is not possible to know the total amount in advance, in which case the second argument is 0. (If you connect to a PySide.QtGui.QProgressBar a total of 0 results in a busy indicator.)
When the response header is read, it is reported with the PySide.QtNetwork.QHttp.responseHeaderReceived() 信号。
PySide.QtNetwork.QHttp.readyRead() signal tells you that there is data ready to be read. The amount of data can then be queried with the PySide.QtNetwork.QHttp.bytesAvailable() function and it can be read with the PySide.QtNetwork.QHttp.read() or PySide.QtNetwork.QHttp.readAll() 函数。
If an error occurs during the execution of one of the commands in a sequence of commands, all the pending commands (i.e. scheduled, but not yet executed commands) are cleared and no signals are emitted for them.
For example, if you have the following sequence of requests
http.setHost("www.foo.bar") # id == 1
http.get("/index.html") # id == 2
http.post("register.html", data) # id == 3
和 PySide.QtNetwork.QHttp.get() request fails because the host lookup fails, then the PySide.QtNetwork.QHttp.post() request is never executed and the signals would look like this:
requestStarted(1)
requestFinished(1, False)
requestStarted(2)
stateChanged(HostLookup)
requestFinished(2, True)
done(True)
stateChanged(Unconnected)
You can then get details about the error with the PySide.QtNetwork.QHttp.error() and PySide.QtNetwork.QHttp.errorString() functions. Note that only unexpected behavior, like network failure is considered as an error. If the server response contains an error status, like a 404 response, this is reported as a normal response case. So you should always check the status code of the response header.
函数 PySide.QtNetwork.QHttp.currentId() and PySide.QtNetwork.QHttp.currentRequest() provide more information about the currently executing request.
函数 PySide.QtNetwork.QHttp.hasPendingRequests() and PySide.QtNetwork.QHttp.clearPendingRequests() allow you to query and clear the list of pending requests.
另请参阅
PySide.QtNetwork.QFtp PySide.QtNetwork.QNetworkAccessManager PySide.QtNetwork.QNetworkRequest PySide.QtNetwork.QNetworkReply HTTP 范例 Torrent Example
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构造 PySide.QtNetwork.QHttp 对象。 parent 参数被传递给 PySide.QtCore.QObject 构造函数。
构造 PySide.QtNetwork.QHttp object. Subsequent requests are done by connecting to the server hostName 在端口 port using the connection mode mode .
If port is 0, it will use the default port for the mode used (80 for Http and 443 for Https).
parent 参数被传递给 PySide.QtCore.QObject 构造函数。
构造 PySide.QtNetwork.QHttp object. Subsequent requests are done by connecting to the server hostName 在端口 port .
parent 参数被传递给 PySide.QtCore.QObject 构造函数。
This enum identifies the error that occurred.
| 常量 | 描述 |
|---|---|
| QHttp.NoError | 没有发生错误。 |
| QHttp.HostNotFound | The host name lookup failed. |
| QHttp.ConnectionRefused | The server refused the connection. |
| QHttp.UnexpectedClose | The server closed the connection unexpectedly. |
| QHttp.InvalidResponseHeader | The server sent an invalid response header. |
| QHttp.WrongContentLength | The client could not read the content correctly because an error with respect to the content length occurred. |
| QHttp.Aborted | The request was aborted with PySide.QtNetwork.QHttp.abort() . |
| QHttp.ProxyAuthenticationRequiredError | PySide.QtNetwork.QHttp is using a proxy, and the proxy server requires authentication to establish a connection. |
| QHttp.AuthenticationRequiredError | The web server requires authentication to complete the request. |
| QHttp.UnknownError | An error other than those specified above occurred. |
This enum is used to specify the mode of connection to use:
| 常量 | 描述 |
|---|---|
| QHttp.ConnectionModeHttp | The connection is a regular HTTP connection to the server |
| QHttp.ConnectionModeHttps | The HTTPS protocol is used and the connection is encrypted using SSL. |
When using the HTTPS mode, care should be taken to connect to the sslErrors signal, and handle possible SSL errors.
This enum is used to specify the state the client is in:
| 常量 | 描述 |
|---|---|
| QHttp.Unconnected | There is no connection to the host. |
| QHttp.HostLookup | A host name lookup is in progress. |
| QHttp.Connecting | An attempt to connect to the host is in progress. |
| QHttp.Sending | The client is sending its request to the server. |
| QHttp.Reading | The client's request has been sent and the client is reading the server's response. |
| QHttp.Connected | The connection to the host is open, but the client is neither sending a request, nor waiting for a response. |
| QHttp.Closing | The connection is closing down, but is not yet closed. (The state will be Unconnected when the connection is closed.) |
Aborts the current request and deletes all scheduled requests.
For the current request, the PySide.QtNetwork.QHttp.requestFinished() signal with the error argument true is emitted. For all other requests that are affected by the PySide.QtNetwork.QHttp.abort() , no signals are emitted.
Since this slot also deletes the scheduled requests, there are no requests left and the PySide.QtNetwork.QHttp.done() signal is emitted (with the error argument true ).
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| 返回类型： | PySide.QtCore.qint64 |
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Returns the number of bytes that can be read from the response content at the moment.
Deletes all pending requests from the list of scheduled requests. This does not affect the request that is being executed. If you want to stop this as well, use PySide.QtNetwork.QHttp.abort() .
| 返回类型： | PySide.QtCore.int |
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Closes the connection; this is useful if you have a keep-alive connection and want to close it.
For the requests issued with PySide.QtNetwork.QHttp.get() , PySide.QtNetwork.QHttp.post() and PySide.QtNetwork.QHttp.head() , PySide.QtNetwork.QHttp sets the connection to be keep-alive. You can also do this using the header you pass to the PySide.QtNetwork.QHttp.request() 函数。 PySide.QtNetwork.QHttp only closes the connection to the HTTP server if the response header requires it to do so.
The function does not block; instead, it returns immediately. The request is scheduled, and its execution is performed asynchronously. The function returns a unique identifier which is passed by PySide.QtNetwork.QHttp.requestStarted() and PySide.QtNetwork.QHttp.requestFinished() .
When the request is started the PySide.QtNetwork.QHttp.requestStarted() signal is emitted. When it is finished the PySide.QtNetwork.QHttp.requestFinished() 信号被发射。
If you want to close the connection immediately, you have to use PySide.QtNetwork.QHttp.abort() 代替。
| 返回类型： | PySide.QtCore.QIODevice |
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返回 PySide.QtCore.QIODevice pointer that is used as to store the data of the HTTP request being executed. If there is no current request or if the request does not store the data to an IO device, this function returns 0.
This function can be used to delete the PySide.QtCore.QIODevice in the slot connected to the PySide.QtNetwork.QHttp.requestFinished() 信号。
| 返回类型： | PySide.QtCore.int |
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Returns the identifier of the HTTP request being executed or 0 if there is no request being executed (i.e. they've all finished).
| 返回类型： | PySide.QtNetwork.QHttpRequestHeader |
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Returns the request header of the HTTP request being executed. If the request is one issued by PySide.QtNetwork.QHttp.setHost() or PySide.QtNetwork.QHttp.close() , it returns an invalid request header, i.e. QHttpRequestHeader.isValid() returns false.
| 返回类型： | PySide.QtCore.QIODevice |
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返回 PySide.QtCore.QIODevice pointer that is used as the data source of the HTTP request being executed. If there is no current request or if the request does not use an IO device as the data source, this function returns 0.
This function can be used to delete the PySide.QtCore.QIODevice in the slot connected to the PySide.QtNetwork.QHttp.requestFinished() 信号。
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| 参数： | arg__1 – PySide.QtCore.bool |
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| 返回类型： | PySide.QtNetwork.QHttp.Error |
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Returns the last error that occurred. This is useful to find out what happened when receiving a PySide.QtNetwork.QHttp.requestFinished() 或 PySide.QtNetwork.QHttp.done() signal with the error argument true .
If you start a new request, the error status is reset to NoError .
| 返回类型： | unicode |
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Returns a human-readable description of the last error that occurred. This is useful to present a error message to the user when receiving a PySide.QtNetwork.QHttp.requestFinished() 或 PySide.QtNetwork.QHttp.done() signal with the error argument true .
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PySide.QtCore.int |
Sends a get request for path to the server set by PySide.QtNetwork.QHttp.setHost() or as specified in the constructor.
path must be a absolute path like /index.html or an absolute URI like http://example.com/index.html and must be encoded with either QUrl.toPercentEncoding() or QUrl.encodedPath() .
If the IO device to is 0 the PySide.QtNetwork.QHttp.readyRead() signal is emitted every time new content data is available to read.
If the IO device to is not 0, the content data of the response is written directly to the device. Make sure that the to pointer is valid for the duration of the operation (it is safe to delete it when the PySide.QtNetwork.QHttp.requestFinished() signal is emitted).
The function does not block; instead, it returns immediately. The request is scheduled, and its execution is performed asynchronously. The function returns a unique identifier which is passed by PySide.QtNetwork.QHttp.requestStarted() and PySide.QtNetwork.QHttp.requestFinished() .
When the request is started the PySide.QtNetwork.QHttp.requestStarted() signal is emitted. When it is finished the PySide.QtNetwork.QHttp.requestFinished() 信号被发射。
| 返回类型： | PySide.QtCore.bool |
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Returns true if there are any requests scheduled that have not yet been executed; otherwise returns false.
The request that is being executed is not considered as a scheduled request.
| 参数： | path – unicode |
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| 返回类型： | PySide.QtCore.int |
Sends a header request for path to the server set by PySide.QtNetwork.QHttp.setHost() or as specified in the constructor.
path must be an absolute path like /index.html or an absolute URI like http://example.com/index.html .
The function does not block; instead, it returns immediately. The request is scheduled, and its execution is performed asynchronously. The function returns a unique identifier which is passed by PySide.QtNetwork.QHttp.requestStarted() and PySide.QtNetwork.QHttp.requestFinished() .
When the request is started the PySide.QtNetwork.QHttp.requestStarted() signal is emitted. When it is finished the PySide.QtNetwork.QHttp.requestFinished() 信号被发射。
Tells the PySide.QtNetwork.QSslSocket used for the Http connection to ignore the errors reported in the PySide.QtNetwork.QHttp.sslErrors() 信号。
Note that this function must be called from within a slot connected to the PySide.QtNetwork.QHttp.sslErrors() signal to have any effect.
| 返回类型： | PySide.QtNetwork.QHttpResponseHeader |
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Returns the received response header of the most recently finished HTTP request. If no response has yet been received QHttpResponseHeader.isValid() will return false.
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PySide.QtCore.int |
这是重载函数。
data is used as the content data of the HTTP request.
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PySide.QtCore.int |
Sends a post request for path to the server set by PySide.QtNetwork.QHttp.setHost() or as specified in the constructor.
path must be an absolute path like /index.html or an absolute URI like http://example.com/index.html and must be encoded with either QUrl.toPercentEncoding() or QUrl.encodedPath() .
The incoming data comes via the data IO device.
If the IO device to is 0 the PySide.QtNetwork.QHttp.readyRead() signal is emitted every time new content data is available to read.
If the IO device to is not 0, the content data of the response is written directly to the device. Make sure that the to pointer is valid for the duration of the operation (it is safe to delete it when the PySide.QtNetwork.QHttp.requestFinished() signal is emitted).
The function does not block; instead, it returns immediately. The request is scheduled, and its execution is performed asynchronously. The function returns a unique identifier which is passed by PySide.QtNetwork.QHttp.requestStarted() and PySide.QtNetwork.QHttp.requestFinished() .
When the request is started the PySide.QtNetwork.QHttp.requestStarted() signal is emitted. When it is finished the PySide.QtNetwork.QHttp.requestFinished() 信号被发射。
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| 参数： | maxlen – PySide.QtCore.qint64 |
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| 返回类型： | QByteArray |
Reads maxlen bytes from the response content into data and returns the number of bytes read. Returns -1 if an error occurred.
| 返回类型： | PySide.QtCore.QByteArray |
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Reads all the bytes from the response content and returns them.
| 参数： | resp – PySide.QtNetwork.QHttpResponseHeader |
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| 返回类型： |
PySide.QtCore.int |
Sends a request to the server set by PySide.QtNetwork.QHttp.setHost() or as specified in the constructor. Uses the header as the HTTP request header. You are responsible for setting up a header that is appropriate for your request.
The incoming data comes via the data IO device.
If the IO device to is 0 the PySide.QtNetwork.QHttp.readyRead() signal is emitted every time new content data is available to read.
If the IO device to is not 0, the content data of the response is written directly to the device. Make sure that the to pointer is valid for the duration of the operation (it is safe to delete it when the PySide.QtNetwork.QHttp.requestFinished() signal is emitted).
The function does not block; instead, it returns immediately. The request is scheduled, and its execution is performed asynchronously. The function returns a unique identifier which is passed by PySide.QtNetwork.QHttp.requestStarted() and PySide.QtNetwork.QHttp.requestFinished() .
When the request is started the PySide.QtNetwork.QHttp.requestStarted() signal is emitted. When it is finished the PySide.QtNetwork.QHttp.requestFinished() 信号被发射。
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| 返回类型： |
PySide.QtCore.int |
这是重载函数。
data is used as the content data of the HTTP request.
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| 参数： | arg__1 – PySide.QtCore.int |
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| 参数： | resp – PySide.QtNetwork.QHttpResponseHeader |
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PySide.QtCore.int |
Sets the HTTP server that is used for requests to hostName 在端口 port .
The function does not block; instead, it returns immediately. The request is scheduled, and its execution is performed asynchronously. The function returns a unique identifier which is passed by PySide.QtNetwork.QHttp.requestStarted() and PySide.QtNetwork.QHttp.requestFinished() .
When the request is started the PySide.QtNetwork.QHttp.requestStarted() signal is emitted. When it is finished the PySide.QtNetwork.QHttp.requestFinished() 信号被发射。
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| 返回类型： |
PySide.QtCore.int |
Sets the HTTP server that is used for requests to hostName 在端口 port using the connection mode mode .
If port is 0, it will use the default port for the mode used (80 for HTTP and 443 for HTTPS).
The function does not block; instead, it returns immediately. The request is scheduled, and its execution is performed asynchronously. The function returns a unique identifier which is passed by PySide.QtNetwork.QHttp.requestStarted() and PySide.QtNetwork.QHttp.requestFinished() .
When the request is started the PySide.QtNetwork.QHttp.requestStarted() signal is emitted. When it is finished the PySide.QtNetwork.QHttp.requestFinished() 信号被发射。
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| 返回类型： |
PySide.QtCore.int |
Enables HTTP proxy support, using the proxy server host 在端口 port . username and password can be provided if the proxy server requires authentication.
范例：
def getTicks(self):
http = QHttp(self)
self.connect(http, SIGNAL('done(bool)'), self, SLOT('showPage()'))
http.setProxy("proxy.example.com", 3128)
http.setHost("ticker.example.com")
http.get("/ticks.asp")
def showPage(self):
self.display(http.readAll())
PySide.QtNetwork.QHttp supports non-transparent web proxy servers only, such as the Squid Web proxy cache server (from http://www.squid.org/ ). For transparent proxying, such as SOCKS5, use PySide.QtNetwork.QNetworkProxy 代替。
注意
PySide.QtNetwork.QHttp.setProxy() has to be called before PySide.QtNetwork.QHttp.setHost() for it to take effect. If PySide.QtNetwork.QHttp.setProxy() is called after PySide.QtNetwork.QHttp.setHost() , then it will not apply until after PySide.QtNetwork.QHttp.setHost() is called again.
另请参阅
| 参数： | proxy – PySide.QtNetwork.QNetworkProxy |
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| 返回类型： | PySide.QtCore.int |
这是重载函数。
Enables HTTP proxy support using the proxy settings from proxy 。若 proxy is a transparent proxy, PySide.QtNetwork.QHttp will call QAbstractSocket.setProxy() on the underlying socket. If the type is QNetworkProxy.HttpCachingProxy , PySide.QtNetwork.QHttp will behave like the previous function.
注意
for compatibility with Qt 4.3, if the proxy type is QNetworkProxy.HttpProxy and the request type is unencrypted (that is, ConnectionModeHttp ), PySide.QtNetwork.QHttp will treat the proxy as a caching proxy.
| 参数： | socket – PySide.QtNetwork.QTcpSocket |
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| 返回类型： | PySide.QtCore.int |
Replaces the internal PySide.QtNetwork.QTcpSocket that PySide.QtNetwork.QHttp uses with socket . This is useful if you want to use your own custom PySide.QtNetwork.QTcpSocket subclass instead of the plain PySide.QtNetwork.QTcpSocket that PySide.QtNetwork.QHttp uses by default. PySide.QtNetwork.QHttp does not take ownership of the socket, and will not delete socket when destroyed.
The function does not block; instead, it returns immediately. The request is scheduled, and its execution is performed asynchronously. The function returns a unique identifier which is passed by PySide.QtNetwork.QHttp.requestStarted() and PySide.QtNetwork.QHttp.requestFinished() .
When the request is started the PySide.QtNetwork.QHttp.requestStarted() signal is emitted. When it is finished the PySide.QtNetwork.QHttp.requestFinished() 信号被发射。
Note: If PySide.QtNetwork.QHttp is used in a non-GUI thread that runs its own event loop, you must move socket to that thread before calling PySide.QtNetwork.QHttp.setSocket() .
另请参阅
QObject.moveToThread() Qt 中的线程支持
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| 返回类型： |
PySide.QtCore.int |
This function sets the user name userName and password password for web pages that require authentication.
The function does not block; instead, it returns immediately. The request is scheduled, and its execution is performed asynchronously. The function returns a unique identifier which is passed by PySide.QtNetwork.QHttp.requestStarted() and PySide.QtNetwork.QHttp.requestFinished() .
When the request is started the PySide.QtNetwork.QHttp.requestStarted() signal is emitted. When it is finished the PySide.QtNetwork.QHttp.requestFinished() 信号被发射。
| 参数： | errors – |
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| 返回类型： | PySide.QtNetwork.QHttp.State |
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Returns the current state of the object. When the state changes, the PySide.QtNetwork.QHttp.stateChanged() 信号被发射。
另请参阅
QHttp.State PySide.QtNetwork.QHttp.stateChanged()
| 参数： | arg__1 – PySide.QtCore.int |
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