如何最有效地拆分QbyteArray？ [英] How to split QbyteArray most efficiently?

问题描述

我想有效地对QByteArray消息进行分区，在1个字节后插入间隙。

QByteArray包含8byte数据。

I want to partition a QByteArray message efficiently, insert gap after 1 byte.
QByteArray contain 8byte data.

EX:
QByteArray qba = AABBCCDDEEFF9988

我想把它写入下面的txt文件中格式。

I want to write this into txt file in the following format.

AA BB CC DD EE FF 99 88

任何帮助都会很棒=）

Any help would be great =)

推荐答案

最好使用 printf 格式化：

This can be best done using printf formatting:

FILE *f = fopen("test.txt", "w");
for (int i = 0; i < qba.size(); i++)
{
    if (i)
        fprintf(f, " ");
    fprintf(f, "%02X", (unsigned char)qba.at(i));
}
fprintf(f, "\n");
fclose(f);

如果您的文件已经通过 fopen 之外的其他方法打开，请检查如果您可以获得打开文件的 FILE 指针，或者使用本地缓冲区使用 sprintf 并将其写入文件。



[更新]

对于现有的 QTextStream 喜欢评论吧可以是：

If your file is already opened by another method than fopen, check if you can get a FILE pointer for the opened file or use sprintf with a local buffer and write that to the file.

[UPDATE]
For an existing QTextStream like from the comment it can be:

mylog << " " << currtTimeStump "," << MsgDLC << "," << frameID << ",";
for (int i = 0; i < qba.size(); i++)
{
    char dataByte[4];
    sprintf(dataByte, " %02X", (unsigned char)qba.at(i));
    mylog << dataByte; 
}
mylog << '\n';

要将char（即byte）作为大写十六进制字符串写入输出流，您可以执行以下操作：

To write a char (i.e. a "byte") as upper case hex string into an output stream, you might do the following:

#include <iostream>
#include <iomanip>
...
ostream& toHex(ostream& output, unsigned char byte) {
    return output << hex
                  << uppercase
                  << setw(2)
                  << setfill('0')
                  << int(byte);
}

用法：

for(int i = 0; i < n; i++) {
    cout << toHex(cout, bytes[i]) << " ";
}
cout << endl;

干杯

Andi

Cheers
Andi

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