如何转换QVector< double>到QBytearray [英] How to convert QVector<double> to QBytearray

问题描述

我想将QVector<double>转换为QBytearray，并且我不知道如何执行此操作. 我试过了，但是程序崩溃了:

I would like to convert QVector<double> to QBytearray, and I have no idea on how to do this. I tried this but the program crashes:

QVector<double> vec;
QByteArray arr = QByteArray::fromRawData(reinterpret_cast<const char*>(vec),vec.size());
for(int i = 0; i< vec.size(); i++)
    arr.append(reinterpret_cast<const char*>(vec.data(&numberOfData),sizeof(double));

有人可以告诉我如何正确执行吗?

Can someone tell me how to do it properly?

推荐答案

您必须传递一个本机数组，这样QByteArray才能接收到一系列连续的字节.

You must pass through a native array, so your QByteArray will receive a sequence of contiguous bytes.

double *bytes = new double[vec.size()];
for (int i = 0; i < vec.size(); ++i) {
   bytes[i] = vec[i];
}
QByteArray array = QByteArray::fromRawData(reinterpret_cast<void*>(bytes));
delete []bytes;

免责声明:未经测试的代码.

Disclaimer: untested code.

-更新---

正如leemes正确指出的那样，您不需要分配和复制字节数组，QVector已经提供了两个对原始数据的访问功能.因此，您可以简单地使用data()和constData(). 请看他的回应.

As leemes correctly pointed out, you DON'T need to allocate and copy a byte array, QVector already provides two access functions to raw data. So you can simply use data() and constData(). Please see his response.

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