用于UDP数据包接收的Qt GUI

我正在使用Qt开发一个GUI，用于测试UDP服务器应用程序，我使用unix中可用的套接字接口用C编写。我的GUI的目标是在"文本编辑框"或"文本浏览器框"中显示所有消息(错误和fprintf)。这是我的代码，

 //-----------------------------Main.Cpp------------------------------------------//
//-----------------------------QT specific headers-------------------------------//
#include "mainwindow.h"
#include <QApplication>
#include <QLabel>
//------------------------------------------------------------------------------------//

int main(int argc, char *argv[])
{
int sock_fd=0;
funct_class funct_class_obj;
QApplication a(argc, argv);
MainWindow w;
sock_fd=funct_class_obj.udp_config();
funct_class_obj.recv_fucnt(sock_fd);
return a.exec();
}
//--------------------------------End of main.cpp------------------------------//
//-----------------------------mainwindow.cpp----------------------------------//
//-----------------------------QT specific headers-----------------------------//
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QApplication>
#include <QLabel>
//-----------------------------------------------------------------------------//

//--------------------------------C program specific headers------------------//
#include <stdio.h>
#include <stdlib.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<sys/types.h>
 //---------------------------------------------------------------------------//

unsigned char message[50];
QString mystr;
int funct_class:: udp_config()
{
     int sock_fd=0;
     if ((sock_fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
        perror("nError creating socketn");
         //mystr = "nError creating socketn";

     else
     {
        fprintf(stdout, "nSuccessfully created socket with descriptor:%dn", sock_fd);
        //mystr = "Successfully created socket";
        struct sockaddr_in sock_addr = {0};
        sock_addr.sin_family = AF_INET;
        sock_addr.sin_port = htons(PORT);
        if (inet_aton("127.0.0.1", &sock_addr.sin_addr) < 0)
        perror("nError converting destination IP address from dotted decimal to     binaryn");
        //    mystr = "Error converting destination IP address from dotted decimal to binary";
     else
     {
        if (bind(sock_fd, (struct sockaddr*)&sock_addr, sizeof(sock_addr)) < 0)                         // Bind function call binds the properties assigned above to the socket created earlier
        perror("nError binding the port and IP address with the socketn");
        //mystr = "Error binding the port and IP address with the socket";
     else
        fprintf(stdout, "nBinding port and IP address successfuln");
        //    mystr = "Binding port and IP address successful";
     }
     }
     return sock_fd;
}

void funct_class:: recv_fucnt(int sock_fd)
{
    struct sockaddr_in recv_sockaddr = {0};
    socklen_t recv_sockaddr_len = sizeof(recv_sockaddr);
    int recv_data=0;
    if ((recv_data = recvfrom(sock_fd, message, sizeof(message), 0x00, (struct     sockaddr*)&recv_sockaddr, &recv_sockaddr_len)) <= 0)
        perror("nError receiving data/no data receivedn");
        //mystr = "Error receiving data/no data received";

        else
        fprintf(stdout, "nSuccessfully received %d bytes of datan", recv_data);
    fprintf(stdout, "nData is :%s", message);
           //mystr = "Successfully received data";
    mystr = QString::fromStdString((const char*)message);

}

MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
ui->testedit->setText(mystr);
//ui->mytextbrowser->setText((mystr));
}

MainWindow::~MainWindow()
{
delete ui;
}
//-----------------------------End of mainwindow.cpp---------------------------//
//------------------------------------mainwindow.h-----------------------------//
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#define PORT 5030

namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();

private:
Ui::MainWindow *ui;
};

class funct_class{
public:
int udp_config();
void recv_fucnt(int sock_fd);
};


 #endif // MAINWINDOW_H

//-------------------------------End of mainwindow.h-----------------------------//

应用程序正在编译，但我面临的问题，当我执行它。它只是冻结，即使我设法把它从冻结中取出，我也无法在"文本编辑框"或"文本浏览器框"中显示所需的字符串。请帮助。

注:我是GUI编程和Cpp的新手。