您从sip.voidptrQImage.constBits转到ctypes void或char指针
问题说明
我正在使用python，当然您不能很快遍历大图像的每个像素，因此我只能使用C DLL。
I'm using python and of course you can't loop through every pixel of a large image very quickly, so I defer to a C DLL.
I想要做这样的事情：
I want to do something like this:
img = QImage("myimage.png").constBits()
imgPtr = c_void_p(img)
found = ctypesDLL.myImageSearchMethod(imgPtr, width, height)
但是这行
imgPtr = c_void_p（img）
产量
But this line imgPtr = c_void_p(img) yelds
builtins.TypeError：无法转换为指针
builtins.TypeError: cannot be converted to pointer
我不需要修改这些位。请教我您在这方面的绝地方式。
I don't need to modify the bits. Please teach me your Jedi ways in this area.
正确答案
如此处， sip.voidptr .__ int __（）方法 p>
As stated here, sip.voidptr.__int__() method
将地址返回为整数
returns the address as an integer
c_void_p 文档说
构造函数接受一个可选的整数初始值设定项。
The constructor accepts an optional integer initializer.
因此您应该能够通过传递 sip.voidptr .__ int __（） c_void_p c $ c>方法构造函数：
So you should be able to build a c_void_p passing the return value of sip.voidptr.__int__() method to its constructor:
imgPtr = c_void_p(img.__int__())
我以此方式测试了此解决方案：
I tested this solution this way:
from PyQt5 import QtGui
from ctypes import *
lib = CDLL("/usr/lib/libtestlib.so")
image = QtGui.QImage("so.png")
bits = image.constBits()
bytes = image.bytesPerLine()
lib.f(c_void_p(bits.__int__()), c_int(image.width()), c_int(image.height()), c_int(bytes))
哪个功能可以正常工作，例如：
Which works fine with a function like:
#include <cstdio>
#include <QImage>
extern "C" {
void f(unsigned char * c, int width, int height, int bpl)
{
printf("W:%d H:%d BPL:%d\n", width, height, bpl);
QImage image(c, width, height, bpl, QImage::Format_RGB32);
image.save("test.bmp");
}
}
这篇好文章是转载于：学新通技术网
