Qt下QByteArray的使用

今天遇到一个问题，想要实现一种功能：在QLineEdit中书写16进制字符串比如 00 01 ff，然后保存为16进制转换后的字节形式到内存中，然后在文件中进行查找字符串匹配，后来发现QByteArray QByteArray::fromHex(const QByteArray & hexEncoded)函数可以实现这个功能。

QByteArray QByteArray::fromHex(const QByteArray & hexEncoded)
Returns a decoded copy of the hex encoded array hexEncoded. Input is not checked for validity; invalid characters in the input are skipped, enabling the decoding process to continue with subsequent characters.

For example:

QByteArray text = QByteArray::fromHex("517420697320677265617421");text.data();            // returns "Qt is great!"

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对于字符串匹配查找方面，我用的是泛型函数库algorithm中的search函数：
具体用法请到:http://www.cplusplus.com中查询，这里只给出例子:

// search algorithm example#include <iostream>     // std::cout#include <algorithm>    // std::search#include <vector>       // std::vectorbool mypredicate (int i, int j) {  return (i==j);}int main () {  std::vector<int> haystack;  // set some values:        haystack: 10 20 30 40 50 60 70 80 90  for (int i=1; i<10; i++) haystack.push_back(i*10);  // using default comparison:  int needle1[] = {40,50,60,70};  std::vector<int>::iterator it;  it = std::search (haystack.begin(), haystack.end(), needle1, needle1+4);  if (it!=haystack.end())    std::cout << "needle1 found at position " << (it-haystack.begin()) << '\n';  else    std::cout << "needle1 not found\n";  // using predicate comparison:  int needle2[] = {20,30,50};  it = std::search (haystack.begin(), haystack.end(), needle2, needle2+3, mypredicate);  if (it!=haystack.end())    std::cout << "needle2 found at position " << (it-haystack.begin()) << '\n';  else    std::cout << "needle2 not found\n";  return 0;}

Output:
needle1 found at position 3
needle2 not found