QDataStream ¶

QDataStream class provides serialization of binary data to a QIODevice . 更多 …

概要 ¶

函数 ¶

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def __lshift__ (, array)
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def __lshift__ (, cursor)
def __lshift__ (, history)
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def __lshift__ (, item)
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def __lshift__ (, ks)
def __lshift__ (, p)
def __lshift__ (, polygon)
def __lshift__ (, re)
def __lshift__ (, regExp)
def __lshift__ (, shape)
def __lshift__ (, tz)
def __lshift__ (, version)
def __lshift__ (arg__1)
def __rshift__ (, arg__2)
def __rshift__ (, arg__2)
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def __rshift__ (, arg__2)
def __rshift__ (, array)
def __rshift__ (, coordinate)
def __rshift__ (, cursor)
def __rshift__ (, history)
def __rshift__ (, info)
def __rshift__ (, info)
def __rshift__ (, item)
def __rshift__ (, item)
def __rshift__ (, item)
def __rshift__ (, item)
def __rshift__ (, ks)
def __rshift__ (, p)
def __rshift__ (, polygon)
def __rshift__ (, re)
def __rshift__ (, regExp)
def __rshift__ (, shape)
def __rshift__ (, tz)
def __rshift__ (, version)
def abortTransaction ()
def atEnd ()
def byteOrder ()
def commitTransaction ()
def device ()
def floatingPointPrecision ()
def readBool ()
def readDouble ()
def readFloat ()
def readInt16 ()
def readInt32 ()
def readInt64 ()
def readInt8 ()
def readQChar ()
def readQString ()
def readQStringList ()
def readQVariant ()
def readRawData (, len)
def readString ()
def readUInt16 ()
def readUInt32 ()
def readUInt64 ()
def readUInt8 ()
def resetStatus ()
def rollbackTransaction ()
def setByteOrder (arg__1)
def setDevice (arg__1)
def setFloatingPointPrecision (precision)
def setStatus (status)
def setVersion (arg__1)
def skipRawData (len)
def startTransaction ()
def status ()
def unsetDevice ()
def version ()
def writeBool (arg__1)
def writeDouble (arg__1)
def writeFloat (arg__1)
def writeInt16 (arg__1)
def writeInt32 (arg__1)
def writeInt64 (arg__1)
def writeInt8 (arg__1)
def writeQChar (arg__1)
def writeQString (arg__1)
def writeQStringList (arg__1)
def writeQVariant (arg__1)
def writeRawData (arg__1)
def writeString (arg__1)
def writeUInt16 (arg__1)
def writeUInt32 (arg__1)
def writeUInt64 (arg__1)
def writeUInt8 (arg__1)

详细描述 ¶

A data stream is a binary stream of encoded information which is 100% independent of the host computer’s operating system, CPU or byte order. For example, a data stream that is written by a PC under Windows can be read by a Sun SPARC running Solaris.

还可以使用数据流去读/写 raw unencoded binary data . If you want a “parsing” input stream, see QTextStream .

QDataStream class implements the serialization of C++’s basic data types, like char , short , int , char * , etc. Serialization of more complex data is accomplished by breaking up the data into primitive units.

A data stream cooperates closely with a QIODevice . A QIODevice represents an input/output medium one can read data from and write data to. The QFile class is an example of an I/O device.

范例 (把二进制数据写入流)：
file_ = QFile("file.dat")
file_.open(QIODevice.WriteOnly)
# we will serialize the data into the file
out = QDataStream(file_)
# serialize a string
out.writeQString("the answer is")
# serialize an integer
out.writeInt32(42)
											
Example (read binary data from a stream):
file_ = QFile("file.dat")
file_.open(QIODevice.ReadOnly)
# read the data serialized from the file
i = QDataStream(file_)
string = ''
a = 0
# extract "the answer is" and 42
string = i.readQString()
a = i.readInt32()
											
Each item written to the stream is written in a predefined binary format that varies depending on the item’s type. Supported Qt types include QBrush , QColor , QDateTime , QFont , QPixmap , QString , QVariant and many others. For the complete list of all Qt types supporting data streaming see 序列化 Qt 数据类型 .

For integers it is best to always cast to a Qt integer type for writing, and to read back into the same Qt integer type. This ensures that you get integers of the size you want and insulates you from compiler and platform differences.

Enumerations can be serialized through QDataStream without the need of manually defining streaming operators. Enum classes are serialized using the declared size.

To take one example, a char * string is written as a 32-bit integer equal to the length of the string including the ‘\0’ byte, followed by all the characters of the string including the ‘\0’ byte. When reading a char * string, 4 bytes are read to create the 32-bit length value, then that many characters for the char * string including the ‘\0’ terminator are read.

The initial I/O device is usually set in the constructor, but can be changed with setDevice() . If you’ve reached the end of the data (or if there is no I/O device set) atEnd() will return true.

版本化 ¶

QDataStream ‘s binary format has evolved since Qt 1.0, and is likely to continue evolving to reflect changes done in Qt. When inputting or outputting complex types, it’s very important to make sure that the same version of the stream ( version() ) is used for reading and writing. If you need both forward and backward compatibility, you can hardcode the version number in the application:
stream.setVersion(QDataStream.Qt_4_0)
												
If you are producing a new binary data format, such as a file format for documents created by your application, you could use a QDataStream to write the data in a portable format. Typically, you would write a brief header containing a magic string and a version number to give yourself room for future expansion. For example:
file_ = QFile("file.xxx")
file_.open(QIODevice.WriteOnly)
out = QDataStream(file_)
# Write a header with a "magic number" and a version
out.writeInt32(0xA0B0C0D0)
out.writeInt32(123)
out.setVersion(QDataStream.Qt_4_0)
// Write the data
out << lots_of_interesting_data
												
Then read it in with:
file_ = QFile("file.xxx")
file_.open(QIODevice.ReadOnly)
i = QDataStream(file_)
// Read and check the header
magic = i.readInt32()
if magic != 0xA0B0C0D0:
    return XXX_BAD_FILE_FORMAT
// Read the version
version = i.readInt32()
if version < 100:
    return XXX_BAD_FILE_TOO_OLD
if version > 123:
    return XXX_BAD_FILE_TOO_NEW
if version <= 110:
    in_.setVersion(QDataStream.Qt_3_2)
else:
    in_.setVersion(QDataStream.Qt_4_0)
// Read the data
in_ >> lots_of_interesting_data
if version >= 120:
    in_ >> data_new_in_XXX_version_1_2
in_ >> other_interesting_data
												
You can select which byte order to use when serializing data. The default setting is big endian (MSB first). Changing it to little endian breaks the portability (unless the reader also changes to little endian). We recommend keeping this setting unless you have special requirements.

读取和写入原生二进制数据 ¶

You may wish to read/write your own raw binary data to/from the data stream directly. Data may be read from the stream into a preallocated char * 使用 readRawData() . Similarly data can be written to the stream using writeRawData() . Note that any encoding/decoding of the data must be done by you.

A similar pair of functions is readBytes() and writeBytes() . These differ from their raw counterparts as follows: readBytes() reads a quint32 which is taken to be the length of the data to be read, then that number of bytes is read into the preallocated char * ; writeBytes() writes a quint32 containing the length of the data, followed by the data. Note that any encoding/decoding of the data (apart from the length quint32) must be done by you.

读取和写入 Qt 集合类 ¶

The Qt container classes can also be serialized to a QDataStream 。这些包括 QList , QLinkedList , QVector , QSet , QHash ，和 QMap . The stream operators are declared as non-members of the classes.

读取和写入其它 Qt 类 ¶

In addition to the overloaded stream operators documented here, any Qt classes that you might want to serialize to a QDataStream will have appropriate stream operators declared as non-member of the class:
QDataStream &operator<<(QDataStream &, const QXxx &);
QDataStream &operator>>(QDataStream &, QXxx &);
												
For example, here are the stream operators declared as non-members of the QImage 类：
QDataStream & operator<< (QDataStream& stream, const QImage& image);
QDataStream & operator>> (QDataStream& stream, QImage& image);
												
To see if your favorite Qt class has similar stream operators defined, check the 相关非成员 section of the class’s documentation page.

使用读取事务 ¶

When a data stream operates on an asynchronous device, the chunks of data can arrive at arbitrary points in time. The QDataStream class implements a transaction mechanism that provides the ability to read the data atomically with a series of stream operators. As an example, you can handle incomplete reads from a socket by using a transaction in a slot connected to the readyRead() signal:
in.startTransaction();
QString str;
qint32 a;
in >> str >> a; // try to read packet atomically
if (!in.commitTransaction())
    return;     // wait for more data
												
If no full packet is received, this code restores the stream to the initial position, after which you need to wait for more data to arrive.

另请参阅

QTextStream QVariant

class QDataStream ¶

QDataStream(arg__1, flags)

QDataStream(arg__1)

QDataStream(arg__1)

param flags

OpenMode

param arg__1

QByteArray

Constructs a data stream that has no I/O device.

另请参阅

setDevice()

Constructs a data stream that operates on a byte array, a 。 mode describes how the device is to be used.

另外，可以使用 QDataStream (const QByteArray &) if you just want to read from a byte array.

Since QByteArray is not a QIODevice subclass, internally a QBuffer is created to wrap the byte array.

Constructs a data stream that uses the I/O device d .

另请参阅

setDevice() device()

PySide2.QtCore.QDataStream. 版本 ¶

This enum provides symbolic synonyms for the data serialization format version numbers.

常量	描述
QDataStream.Qt_1_0	Version 1 (Qt 1.x)
QDataStream.Qt_2_0	Version 2 (Qt 2.0)
QDataStream.Qt_2_1	Version 3 (Qt 2.1, 2.2, 2.3)
QDataStream.Qt_3_0	Version 4 (Qt 3.0)
QDataStream.Qt_3_1	Version 5 (Qt 3.1, 3.2)
QDataStream.Qt_3_3	Version 6 (Qt 3.3)
QDataStream.Qt_4_0	Version 7 (Qt 4.0, Qt 4.1)
QDataStream.Qt_4_1	Version 7 (Qt 4.0, Qt 4.1)
QDataStream.Qt_4_2	Version 8 (Qt 4.2)
QDataStream.Qt_4_3	Version 9 (Qt 4.3)
QDataStream.Qt_4_4	Version 10 (Qt 4.4)
QDataStream.Qt_4_5	Version 11 (Qt 4.5)
QDataStream.Qt_4_6	Version 12 (Qt 4.6, Qt 4.7, Qt 4.8)
QDataStream.Qt_4_7	Same as .
QDataStream.Qt_4_8	Same as .
QDataStream.Qt_4_9	Same as .
QDataStream.Qt_5_0	Version 13 (Qt 5.0)
QDataStream.Qt_5_1	Version 14 (Qt 5.1)
QDataStream.Qt_5_2	Version 15 (Qt 5.2)
QDataStream.Qt_5_3	如同
QDataStream.Qt_5_4	Version 16 (Qt 5.4)
QDataStream.Qt_5_5	如同
QDataStream.Qt_5_6	Version 17 (Qt 5.6)
QDataStream.Qt_5_7	如同
QDataStream.Qt_5_8	如同
QDataStream.Qt_5_9	如同
QDataStream.Qt_5_10	如同
QDataStream.Qt_5_11	如同
QDataStream.Qt_5_12	Version 18 (Qt 5.12)
QDataStream.Qt_5_13	Version 19 (Qt 5.13)
QDataStream.Qt_5_14	如同
QDataStream.Qt_5_15	如同

另请参阅

setVersion() version()

PySide2.QtCore.QDataStream. ByteOrder ¶

用于读/写数据的字节序。

常量	描述
QDataStream.BigEndian	Most significant byte first (the default)
QDataStream.LittleEndian	Least significant byte first

PySide2.QtCore.QDataStream. Status ¶

This enum describes the current status of the data stream.

常量	描述
QDataStream.Ok	The data stream is operating normally.
QDataStream.ReadPastEnd	The data stream has read past the end of the data in the underlying device.
QDataStream.ReadCorruptData	The data stream has read corrupt data.
QDataStream.WriteFailed	The data stream cannot write to the underlying device.

PySide2.QtCore.QDataStream. FloatingPointPrecision ¶

The precision of floating point numbers used for reading/writing the data. This will only have an effect if the version of the data stream is Qt_4_6 or higher.

警告

The floating point precision must be set to the same value on the object that writes and the object that reads the data stream.

常量	描述
QDataStream.SinglePrecision	All floating point numbers in the data stream have 32-bit precision.
QDataStream.DoublePrecision	All floating point numbers in the data stream have 64-bit precision.

另请参阅

setFloatingPointPrecision() floatingPointPrecision()

4.6 版新增。

PySide2.QtCore.QDataStream. abortTransaction ( ) ¶

Aborts a read transaction.

This function is commonly used to discard the transaction after higher-level protocol errors or loss of stream synchronization.

If called on an inner transaction, aborting is delegated to the outermost transaction, and subsequently started inner transactions are forced to fail.

For the outermost transaction, discards the restoration point and any internally duplicated data of the stream. Will not affect the current read position of the stream.

Sets the status of the data stream to

ReadCorruptData
.

另请参阅

startTransaction() commitTransaction() rollbackTransaction()

PySide2.QtCore.QDataStream. atEnd ( ) ¶

返回类型: bool

返回 true if the I/O device has reached the end position (end of the stream or file) or if there is no I/O device set; otherwise returns false .

另请参阅

atEnd()

PySide2.QtCore.QDataStream. byteOrder ( ) ¶

返回类型: ByteOrder

Returns the current byte order setting – either BigEndian or LittleEndian .

另请参阅

setByteOrder()

PySide2.QtCore.QDataStream. commitTransaction ( ) ¶

返回类型: bool

Completes a read transaction. Returns true if no read errors have occurred during the transaction; otherwise returns false .

If called on an inner transaction, committing will be postponed until the outermost , rollbackTransaction() ，或 abortTransaction() call occurs.

Otherwise, if the stream status indicates reading past the end of the data, this function restores the stream data to the point of the startTransaction() call. When this situation occurs, you need to wait for more data to arrive, after which you start a new transaction. If the data stream has read corrupt data or any of the inner transactions was aborted, this function aborts the transaction.

另请参阅

startTransaction() rollbackTransaction() abortTransaction()

PySide2.QtCore.QDataStream. device ( ) ¶

返回类型: QIODevice

Returns the I/O device currently set, or None if no device is currently set.

另请参阅

setDevice()

PySide2.QtCore.QDataStream. floatingPointPrecision ( ) ¶

返回类型: FloatingPointPrecision

Returns the floating point precision of the data stream.

另请参阅

FloatingPointPrecision setFloatingPointPrecision()

PySide2.QtCore.QDataStream. __lshift__ ( re ) ¶

参数: re – QRegularExpression
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QSize
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QSizeF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QSizePolicy
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( item ) ¶

参数: item – QStandardItem
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QTextFormat
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QTextLength
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QTime
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QPixmap
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( tz ) ¶

参数: tz – QTimeZone
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QRegion
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( regExp ) ¶

参数: regExp – QRegExp
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QRectF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QRect
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QQuaternion
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( array ) ¶

参数: array – QPolygonF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( polygon ) ¶

参数: polygon – QPolygon
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QPointF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QPoint
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( item ) ¶

参数: item – QTableWidgetItem
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QTransform
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( history ) ¶

参数: history – QWebEngineHistory
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( version ) ¶

参数: version – QVersionNumber
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QVector4D
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QVector3D
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QVector2D
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QUuid
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QUrl
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( item ) ¶

参数: item – QTreeWidgetItem
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QColorSpace
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( shape ) ¶

参数: shape – QGeoShape
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( info ) ¶

参数: info – QGeoSatelliteInfo
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( info ) ¶

参数: info – QGeoPositionInfo
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( coordinate ) ¶

参数: coordinate – QGeoCoordinate
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QGeoAreaMonitorInfo
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QFont
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QEasingCurve
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QDateTime
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QDate
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( cursor ) ¶

参数: cursor – QCursor
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QColor
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QCborValue
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QCborMap
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QCborArray
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QByteArray
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QBrush
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QBitArray
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__1 ) ¶

参数: arg__1 – unicode

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QIcon
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QPen
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( p ) ¶

参数: p – QPalette
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QPainterPath
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QNetworkCacheMetaData
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QMatrix4x4
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QMatrix
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QMarginsF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QMargins
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QLocale
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( item ) ¶

参数: item – QListWidgetItem
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QLineF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QHostAddress
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QImage
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QJsonArray
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QJsonDocument
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QJsonValue
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( ks ) ¶

参数: ks – QKeySequence
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QLine
返回类型: QDataStream

PySide2.QtCore.QDataStream. __lshift__ ( arg__2 ) ¶

参数: arg__2 – QPicture
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QPointF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( item ) ¶

参数: item – QTreeWidgetItem
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QTransform
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( tz ) ¶

参数: tz – QTimeZone
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QTime
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QTextLength
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QTextFormat
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( item ) ¶

参数: item – QTableWidgetItem
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( item ) ¶

参数: item – QStandardItem
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QSizePolicy
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QSizeF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QSize
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( re ) ¶

参数: re – QRegularExpression
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QRegion
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( regExp ) ¶

参数: regExp – QRegExp
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QRectF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QRect
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QQuaternion
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( array ) ¶

参数: array – QPolygonF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( polygon ) ¶

参数: polygon – QPolygon
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QIcon
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QUrl
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( history ) ¶

参数: history – QWebEngineHistory
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( version ) ¶

参数: version – QVersionNumber
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QVector4D
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QVector3D
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QVector2D
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QUuid
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( cursor ) ¶

参数: cursor – QCursor
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QHostAddress
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( shape ) ¶

参数: shape – QGeoShape
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( info ) ¶

参数: info – QGeoPositionInfo
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( coordinate ) ¶

参数: coordinate – QGeoCoordinate
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QGeoAreaMonitorInfo
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QFont
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QEasingCurve
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QDateTime
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QDate
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( info ) ¶

参数: info – QGeoSatelliteInfo
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QColorSpace
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QColor
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QCborValue
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QCborMap
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QCborArray
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QByteArray
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QBrush
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QBitArray
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QPoint
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QMatrix
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QPixmap
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QPicture
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QPen
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( p ) ¶

参数: p – QPalette
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QPainterPath
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QNetworkCacheMetaData
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QMatrix4x4
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QImage
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QMarginsF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QMargins
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QLocale
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( item ) ¶

参数: item – QListWidgetItem
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QLineF
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QLine
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( ks ) ¶

参数: ks – QKeySequence
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QJsonValue
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QJsonDocument
返回类型: QDataStream

PySide2.QtCore.QDataStream. __rshift__ ( arg__2 ) ¶

参数: arg__2 – QJsonArray
返回类型: QDataStream

PySide2.QtCore.QDataStream. readBool ( ) ¶

返回类型: bool

PySide2.QtCore.QDataStream. readDouble ( ) ¶

返回类型: qreal

PySide2.QtCore.QDataStream. readFloat ( ) ¶

返回类型: float

PySide2.QtCore.QDataStream. readInt16 ( ) ¶

返回类型: qint16

PySide2.QtCore.QDataStream. readInt32 ( ) ¶

返回类型: qint32

PySide2.QtCore.QDataStream. readInt64 ( ) ¶

返回类型: qint64

PySide2.QtCore.QDataStream. readInt8 ( ) ¶

返回类型: qint8

PySide2.QtCore.QDataStream. readQChar ( ) ¶

返回类型: QChar

PySide2.QtCore.QDataStream. readQString ( ) ¶

返回类型: unicode

PySide2.QtCore.QDataStream. readQStringList ( ) ¶

返回类型: 字符串列表

PySide2.QtCore.QDataStream. readQVariant ( ) ¶

返回类型: object

PySide2.QtCore.QDataStream. readRawData ( len ) ¶

参数: len – int
返回类型: int

读取最多 len bytes from the stream into s and returns the number of bytes read. If an error occurs, this function returns -1.

The buffer s must be preallocated. The data is not decoded.

另请参阅

readBytes() read() writeRawData()

PySide2.QtCore.QDataStream. readString ( ) ¶

返回类型: unicode

PySide2.QtCore.QDataStream. readUInt16 ( ) ¶

返回类型: quint16

PySide2.QtCore.QDataStream. readUInt32 ( ) ¶

返回类型: quint32

PySide2.QtCore.QDataStream. readUInt64 ( ) ¶

返回类型: quint64

PySide2.QtCore.QDataStream. readUInt8 ( ) ¶

返回类型: quint8

PySide2.QtCore.QDataStream. resetStatus ( ) ¶: Resets the status of the data stream.

另请参阅

Status status() setStatus()

PySide2.QtCore.QDataStream. rollbackTransaction ( ) ¶

Reverts a read transaction.

This function is commonly used to rollback the transaction when an incomplete read was detected prior to committing the transaction.

If called on an inner transaction, reverting is delegated to the outermost transaction, and subsequently started inner transactions are forced to fail.

For the outermost transaction, restores the stream data to the point of the startTransaction() call. If the data stream has read corrupt data or any of the inner transactions was aborted, this function aborts the transaction.

If the preceding stream operations were successful, sets the status of the data stream to

ReadPastEnd
.

另请参阅

startTransaction() commitTransaction() abortTransaction()

PySide2.QtCore.QDataStream. setByteOrder ( arg__1 ) ¶

参数: arg__1 – ByteOrder

Sets the serialization byte order to bo .

bo parameter can be BigEndian or LittleEndian .

The default setting is big endian. We recommend leaving this setting unless you have special requirements.

另请参阅

byteOrder()

PySide2.QtCore.QDataStream. setDevice ( arg__1 ) ¶

参数: arg__1 – QIODevice

void ( QIODevice *d)

Sets the I/O device to d , which can be None to unset to current I/O device.

另请参阅

device()

PySide2.QtCore.QDataStream. setFloatingPointPrecision ( precision ) ¶

参数: precision – FloatingPointPrecision

Sets the floating point precision of the data stream to precision . If the floating point precision is DoublePrecision and the version of the data stream is Qt_4_6 or higher, all floating point numbers will be written and read with 64-bit precision. If the floating point precision is SinglePrecision and the version is Qt_4_6 or higher, all floating point numbers will be written and read with 32-bit precision.

For versions prior to Qt_4_6 , the precision of floating point numbers in the data stream depends on the stream operator called.

默认为 DoublePrecision .

Note that this property does not affect the serialization or deserialization of qfloat16 实例。

警告

This property must be set to the same value on the object that writes and the object that reads the data stream.

另请参阅

floatingPointPrecision()

PySide2.QtCore.QDataStream. setStatus ( status ) ¶

参数: status – Status

Sets the status of the data stream to the status 给定。

Subsequent calls to are ignored until resetStatus() 被调用。

另请参阅

Status status() resetStatus()

PySide2.QtCore.QDataStream. setVersion ( arg__1 ) ¶

参数: arg__1 – int

Sets the version number of the data serialization format to v , a value of the 版本 枚举。

You don’t have to set a version if you are using the current version of Qt, but for your own custom binary formats we recommend that you do; see 版本化 in the Detailed Description.

To accommodate new functionality, the datastream serialization format of some Qt classes has changed in some versions of Qt. If you want to read data that was created by an earlier version of Qt, or write data that can be read by a program that was compiled with an earlier version of Qt, use this function to modify the serialization format used by QDataStream .

版本 enum provides symbolic constants for the different versions of Qt. For example:

												out = QDataStream(file_)
out.setVersion(QDataStream.Qt_4_0)

另请参阅

version() 版本

PySide2.QtCore.QDataStream. skipRawData ( len ) ¶

参数: len – int
返回类型: int

Skips len 字节从设备。返回实际跳过字节数，或 -1 当出错时。

这相当于调用 readRawData() on a buffer of length len and ignoring the buffer.

另请参阅

seek()

PySide2.QtCore.QDataStream. startTransaction ( ) ¶

Starts a new read transaction on the stream.

Defines a restorable point within the sequence of read operations. For sequential devices, read data will be duplicated internally to allow recovery in case of incomplete reads. For random-access devices, this function saves the current position of the stream. Call commitTransaction() , rollbackTransaction() ，或 abortTransaction() to finish the current transaction.

Once a transaction is started, subsequent calls to this function will make the transaction recursive. Inner transactions act as agents of the outermost transaction (i.e., report the status of read operations to the outermost transaction, which can restore the position of the stream).

注意

Restoring to the point of the nested call is not supported.

When an error occurs during a transaction (including an inner transaction failing), reading from the data stream is suspended (all subsequent read operations return empty/zero values) and subsequent inner transactions are forced to fail. Starting a new outermost transaction recovers from this state. This behavior makes it unnecessary to error-check every read operation separately.

另请参阅

commitTransaction() rollbackTransaction() abortTransaction()

PySide2.QtCore.QDataStream. status ( ) ¶

返回类型: Status

Returns the status of the data stream.

另请参阅

Status setStatus() resetStatus()

PySide2.QtCore.QDataStream. unsetDevice ( ) ¶: 注意

此函数被弃用。

Unsets the I/O device. Use setDevice (nullptr) instead.

PySide2.QtCore.QDataStream. version ( ) ¶

返回类型: int

Returns the version number of the data serialization format.

另请参阅

setVersion() 版本

PySide2.QtCore.QDataStream. writeBool ( arg__1 ) ¶

参数: arg__1 – bool

PySide2.QtCore.QDataStream. writeDouble ( arg__1 ) ¶

参数: arg__1 – qreal

PySide2.QtCore.QDataStream. writeFloat ( arg__1 ) ¶

参数: arg__1 – float

PySide2.QtCore.QDataStream. writeInt16 ( arg__1 ) ¶

参数: arg__1 – qint16

PySide2.QtCore.QDataStream. writeInt32 ( arg__1 ) ¶

参数: arg__1 – qint32

PySide2.QtCore.QDataStream. writeInt64 ( arg__1 ) ¶

参数: arg__1 – qint64

PySide2.QtCore.QDataStream. writeInt8 ( arg__1 ) ¶

参数: arg__1 – qint8

PySide2.QtCore.QDataStream. writeQChar ( arg__1 ) ¶

参数: arg__1 – QChar

PySide2.QtCore.QDataStream. writeQString ( arg__1 ) ¶

参数: arg__1 – unicode

PySide2.QtCore.QDataStream. writeQStringList ( arg__1 ) ¶

参数: arg__1 – 字符串列表

PySide2.QtCore.QDataStream. writeQVariant ( arg__1 ) ¶

参数: arg__1 – object

PySide2.QtCore.QDataStream. writeRawData ( arg__1 ) ¶

参数: arg__1 – str
返回类型: int

写入 len 字节来自 s to the stream. Returns the number of bytes actually written, or -1 on error. The data is not encoded.

另请参阅

writeBytes() write() readRawData()

PySide2.QtCore.QDataStream. writeString ( arg__1 ) ¶

参数: arg__1 – unicode

PySide2.QtCore.QDataStream. writeUInt16 ( arg__1 ) ¶

参数: arg__1 – quint16

PySide2.QtCore.QDataStream. writeUInt32 ( arg__1 ) ¶

参数: arg__1 – quint32

PySide2.QtCore.QDataStream. writeUInt64 ( arg__1 ) ¶

参数: arg__1 – quint64

PySide2.QtCore.QDataStream. writeUInt8 ( arg__1 ) ¶

参数: arg__1 – quint8

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