#include <string>
#include <iostream>

int main(){
  std::string temp = "abc\0def";
  std::cout<<temp.length()<<std::endl;//没错，和你想的一样，输出是3.原因是：temp初始化是用了std：：string（const char×）构造，而char×是会被字符‘\0’截断的！
  std：：string ss = "mmmmmmmm";//8个m
  ss[0] = ‘a’；
  ss[1] = ‘b’；
  ss[2] = ‘c’；
  ss[3] = ‘\0’；
  ss[4] = ‘d’；
  ss[5] = ‘e’；
  ss[6] = ‘f’；
  std::cout<<ss.length()<<std::endl;//输出为8
  QMessage::information(this,"test window",QString("ss = %1").arg(QString::fromStdString(ss)));//输出为abcdefm
   std::cout<<int(ss[3])<<std::endl;//输出为0，即字符‘\0’
}