unsigned char[]和unsigned char*转换

可以使用以下方法将unsigned char[]转换为unsigned char*：

unsigned char arr[] = {0x12, 0x34, 0x56};
unsigned char* ptr = arr;

可以使用以下方法将unsigned char*转换为unsigned char[]：

unsigned char* ptr = new unsigned char[3];
ptr[0] = 0x12;
ptr[1] = 0x34;
ptr[2] = 0x56;
unsigned char arr[3];
std::memcpy(arr, ptr, sizeof(arr));
delete[] ptr;

相关问题

imagecamera.o: In function `yuyv_to_rgb888(unsigned char*, unsigned char*, int, int)': imagecamera.cpp:(.text+0x0): multiple definition of `yuyv_to_rgb888(unsigned char*, unsigned char*, int, int)' main.o:main.cpp:(.text+0x538): first defined here imagedrivecamera.o: In function `yuyv_to_rgb888(unsigned char*, unsigned char*, int, int)': imagedrivecamera.cpp:(.text+0x0): multiple definition of `yuyv_to_rgb888(unsigned char*, unsigned char*, int, int)' main.o:main.cpp:(.text+0x538): first defined here moc_imagecamera.o: In function `yuyv_to_rgb888(unsigned char*, unsigned char*, int, int)': moc_imagecamera.cpp:(.text+0x118): multiple definition of `yuyv_to_rgb888(unsigned char*, unsigned char*, int, int)' main.o:main.cpp:(.text+0x538): first defined here moc_imagedrivecamera.o: In function `yuyv_to_rgb888(unsigned char*, unsigned char*, int, int)': moc_imagedrivecamera.cpp:(.text+0x118): multiple definition of `yuyv_to_rgb888(unsigned char*, unsigned char*, int, int)' main.o:main.cpp:(.text+0x538): first defined here

这是因为在多个源文件中都定义了相同名称的函数，导致链接器无法确定使用哪个定义。解决方法是将函数定义放在单独的源文件中，并将函数原型声明放在头文件中。然后在需要使用该函数的源文件中包含头文件即可。如果多个源文件都需要使用该函数，则需要在其中一个源文件中定义该函数，并在其他源文件中使用extern关键字声明该函数。例如：

// function.h
#ifndef FUNCTION_H
#define FUNCTION_H

void yuyv_to_rgb888(unsigned char* yuv, unsigned char* rgb, int imgWidth, int imgHeight);

#endif

// function.cpp
#include "function.h"

void yuyv_to_rgb888(unsigned char* yuv, unsigned char* rgb, int imgWidth, int imgHeight) {
// 函数实现
}

// main.cpp
#include "function.h"

int main() {
// 调用函数
yuyv_to_rgb888(yuv, rgb, width, height);
return 0;
}

// other.cpp
#include "function.h"

extern void yuyv_to_rgb888(unsigned char* yuv, unsigned char* rgb, int imgWidth, int imgHeight);

void otherFunction() {
// 调用函数
yuyv_to_rgb888(yuv, rgb, width, height);
}

char* 和unsigned char*怎么转换

`char *` 和 `unsigned char *` 之间的转换可以通过类型转换来实现。具体而言，可以将 `char *` 类型的指针强制转换为 `unsigned char *` 类型的指针，或者将 `unsigned char *` 类型的指针强制转换为 `char *` 类型的指针。

示例代码如下：

const char* str = "Hello, World!";
unsigned char* ustr = reinterpret_cast<unsigned char*>(const_cast<char*>(str));

// 或者

unsigned char ustr[] = {0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x2c, 0x20, 0x57, 0x6f, 0x72, 0x6c, 0x64, 0x21};
char* str = reinterpret_cast<char*>(ustr);

需要注意的是，在进行类型转换时要注意指针所指向的内存区域的类型和大小，避免出现指针越界等问题。