QT里endl无法识别
以下是问题代码的头文件和代码部分
求解答
```c++
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <iostream>
#include <QTextStream>
#include <QFile>
void MainWindow::on_pushButton_clicked()
{
QFile initial_D("C://Users//19878//Desktop//demo2.0//untitled//example.txt"); //创建文件存放的路径
if(!initial_D.open(QIODevice::Append|QIODevice::Text)){
qDebug()<<"Error opening file";
return;
}
// initial_D.open(QIODevice::Append|QIODevice::Text);//Append可以连续的输入内容而不被覆盖
QTextStream in(&initial_D);
using namespace std;
in <<"hello world"<<endl;
initial_D.close();//关闭文件
}
```