QUdpSocket，为什么只有在发送使用QHostAddress::Broadcast时，我的接收端才能接收端信息呢

QHostAddress(“192.168.1.5”)这种指定ip，在接收端无法接收
只能使用QHostAddress(“255.255.255.255”)或者QHostAddress::Broadcast，我在测试发送QHostAddress::LocalHost也无法在本机接收

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include<QDebug>
#include <QHostInfo>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    //本地主机名
        QString hostName = QHostInfo::localHostName();

        //本机IP地址
        QHostInfo hostInfo = QHostInfo::fromName(hostName);

        //IP地址列表
        QList<QHostAddress> addrList = hostInfo.addresses();
        for(int i=0;i<addrList.count();i++)
        {
            QHostAddress host = addrList.at(i);

            if(QAbstractSocket::IPv4Protocol == host.protocol())
            {
                QString ip = host.toString();
                ui->comboBox->addItem(ip);
            }
        }

    udpSocket=new QUdpSocket(this);
    if(udpSocket->bind(5050))
        qDebug()<<"绑定成功";
    connect(udpSocket,&QUdpSocket::readyRead,this,&MainWindow::showtext);
}

MainWindow::~MainWindow()
{
    delete ui;
}


void MainWindow::on_Button_send_clicked()
{
    mystruct test;
    test.testport=5050;
    strcpy(test.text,"你好");

    test.size=sizeof (test.text);

//    udpSocket->writeDatagram((char *)&test,sizeof(test),QHostAddress(ui->comboBox->currentText()),5050);
    udpSocket->writeDatagram((char *)&test,sizeof(test),QHostAddress("127.0.0.1"),5050);
}

void MainWindow::showtext()
{
    mystruct s;
    while (udpSocket->hasPendingDatagrams())
    {
        udpSocket->readDatagram((char*)&s,sizeof (s));
        ui->text_receive->appendPlainText(s.text);
        qDebug()<<"接收成功";
    }
}

因为发送端指定IP后，数据会自动发送到接收端对应的IP及端口，所以接收端不需要设置IP。