在 Pyside 中，为什么发出一个整数 > > 0x7FFFFFFF 导致“溢出错误”信号处理后？
我正在尝试使用具有 0 - 2^32-1 范围内的大整数的信号/槽。我发现了一些奇怪的事情——一旦我发出> 7FFFFFFF 边界，我在插槽运行后抛出 OverflowError 异常。如果我或 QT 在另一种语言（如 C 或 C++）中显式使用带符号的 32 位整数，我可能会预料到这种溢出 - 因为我们都知道 0x80000000 在 2 补码表示法中回绕为 -2^31。但在 python 中，没有换行的话它只是 2^32。我在编写代码时的假设是，这是 python 并且内置 int 可以变得非常大（也许是任意的？）并且我不需要明确地将某些东西定义为 32 或 64 位或有符号/无符号。这一切都会奏效。
下面的代码演示了我所看到的内容（Python 2.7.2（64 位）、Pyside 1.1.0、Windows 7）
from PySide.QtCore import *
@Slot(int)
def say(i):
print "Say %i" % i
class Communicate(QObject):
speak = Signal(int)
someone = Communicate()
someone.speak.connect(say)
someone.speak.emit(0x7FFFFFFF) #works fine
someone.speak.emit(0x80000000) #OverflowError after slot "say" runs
say(0x80000000) #works fine
确切的输出是：
Say 2147483647 Say -2147483648 OverflowError Say 2147483648
- Why does Qt似乎将整数类型的信号/槽视为处理有符号的 32 位整数而不是 python 内置整数？
- 如果这是 Qt 的限制，我该怎么做才能将 int 标记为无符号或确保 QT 可以处理整数 > 0x7FFFFFFF？
I'm attempting to use signals/slots with large integers ranging from 0 - 2^32-1. I've discovered something a little weird -- once I emit > 7FFFFFFF boundary, I get OverflowError exceptions thrown after the slot is run. I might expect this kind of overflow if I or QT were explicitly using a signed 32 bit integer in another language like C or C++--as we all know 0x80000000 wraps back to -2^31 in 2s complement notation. In python though, its just 2^32 without wrapping. My assumption when writing the code though was that this is python and that the built-in int can grow very large (maybe arbitrarilly so?) and that I don't explicitly need to define something as 32 or 64 bit or signed/unsigned. It would all just work.
The code below demonstrates what I'm seeing (Python 2.7.2 (64 bit), Pyside 1.1.0, Windows 7)
from PySide.QtCore import *
@Slot(int)
def say(i):
print "Say %i" % i
class Communicate(QObject):
speak = Signal(int)
someone = Communicate()
someone.speak.connect(say)
someone.speak.emit(0x7FFFFFFF) #works fine
someone.speak.emit(0x80000000) #OverflowError after slot "say" runs
say(0x80000000) #works fine
The exact output is:
Say 2147483647 Say -2147483648 OverflowError Say 2147483648
- Why does Qt seem to treat the signals/slots of type integer as if its dealing with signed 32 bit integers and not python built-in ints?
- If this is a restriction of Qt, what can I do to mark the int as unsigned or make sure QT can deal with integers > 0x7FFFFFFF?
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我主要是 PyQt 用户，但我相信行为是相似的。信号定义中的
int映射为 4 字节整数（Qt 理解int）。一种可能的解决方案是强制信号发出 Python 对象。这是可行的：
但请注意，如果您将此信号连接到需要 Qt 版本的
int的插槽（例如QtGui.QSpinBox.setMaximum），您会看到相同的行为。除此之外，纯粹在 Python 端使用这个信号应该没问题。I'm mostly a PyQt user, but I believe the behavior is similar.
intin signal definition is mapped to 4-byte integer (as Qt understands anint).One possible solution is to force the signal to emit a Python object. This works:
But be aware that, if you connect this signal to a slot that expects a Qt's version of
int(for exampleQtGui.QSpinBox.setMaximum) you'll see the same behavior. Other than that, using this signal purely on the Python side should be fine.