求助：这个程序究竟哪里错了

[AAA20090987]

下面这个程序的功能是：
客户端先向服务器发送“1”，然后服务器向客户端发出询问("Are you a boy")，
用户如果选close，就结束通信
选yes，则向服务器发送2，然后在服务器界面上显示"He is a boy"，服务器向客户端发送"Oh, you are a boy"
选no，则向服务器发送3，然后在服务器界面上显示"She is a girl"，服务器向客户端发送"Oh, you are a girl"
最后，客户端弹出一个消息窗口，显示"Oh, you are a boy"或"Oh, you are a girl"，结束。

但不知为什么，最后并没有弹出那个消息窗口，客户端似乎没有收到信息。
这是为什么呢？应该怎么改正？

客户端：

//trycli.h

#ifndef TRYCLI_H_
#define TRYCLI_H_

#include <QtGui/QWidget>
#include <QtNetwork/QTcpSocket>
#include <QtGui/QPushButton>
#include <QtCore/QString>
#include <QtCore/QVector>
#include <QtCore/QTimer>
#include "ui_client.h"

class client : public QWidget
{
	Q_OBJECT
private:
	QPushButton *start;
	QTcpSocket *tcpclient;
	quint16 blockSize;
	QString sendString;
	QString readString;

public:
	client();
	~client();
	void Question(const QString &str);

	public slots:
		void displayError(QAbstractSocket::SocketError socketError);
		void newConnect();
		void clickedStartButton();
		void readMessage();
		void sendMessage();
		
};

#endif


//trycli.cpp

#include "trycli.h"
#include <QtGui/QMessageBox>
#include <QtGui/QHBoxLayout>
#include <QtEvents>

client::client()
{
	setWindowTitle("client");
	resize(100, 100);

	start = new QPushButton("start");
	QHBoxLayout *layout = new QHBoxLayout;
	layout->addWidget(start);
	setLayout(layout);

	tcpclient = new QTcpSocket(this);
	connect(start, SIGNAL(clicked()), this, SLOT(clickedStartButton()));
	connect(tcpclient, SIGNAL(connected()), this, SLOT(sendMessage()));
	connect(tcpclient, SIGNAL(readyRead()), this, SLOT(readMessage()));
	connect(tcpclient, SIGNAL(error(QAbstractSocket::SocketError)),
		this, SLOT(displayError(QAbstractSocket::SocketError)));
}

client::~client()
{

}

void client::newConnect()
{
	blockSize = 0;
	tcpclient->abort();
	tcpclient->connectToHost("127.0.0.1", 8888);
	tcpclient->waitForReadyRead();
}

void client::sendMessage()
{
	QByteArray block;
	QDataStream out(&block, QIODevice::WriteOnly);
	out.setVersion(QDataStream::Qt_4_0);

	out << (quint16)0;
	out << sendString;
	out.device()->seek(0);
	out << (quint16)(block.size() - sizeof(quint16));

	tcpclient->write(block);
}

void client::readMessage()
{
	QDataStream in(tcpclient);
	in.setVersion(QDataStream::Qt_4_0);

	if (blockSize == 0)
	{
		if (tcpclient->bytesAvailable() < (int)sizeof(quint16))
			return;
		in >> blockSize;
	}
	if (tcpclient->bytesAvailable() < blockSize)
		return;

	in >> readString;
	if(readString[0] == 'A')
		Question(readString);
	else
		QMessageBox::about(NULL, "AA", readString);
	tcpclient->disconnectFromHost();
}

void client::displayError(QAbstractSocket::SocketError socketError)
{
	switch (socketError) {
	case QAbstractSocket::RemoteHostClosedError:
		break;
	case QAbstractSocket::HostNotFoundError:
		QMessageBox::information(this, tr("Fortune Client"),
			tr("The host was not found. Please check the "
			"host name and port settings."));
		break;
	case QAbstractSocket::ConnectionRefusedError:
		QMessageBox::information(this, tr("Fortune Client"),
			tr("The connection was refused by the peer. "
			"Make sure the fortune server is running, "
			"and check that the host name and port "
			"settings are correct."));
		break;
	default:
		QMessageBox::information(this, tr("Fortune Client"),
			tr("The following error occurred: %1.")
			.arg(tcpclient->errorString()));
	}
}

void client::clickedStartButton()
{
	sendString = "1";
	newConnect();
}

void client::Question(const QString &str)
{
	QMessageBox::StandardButton rb = QMessageBox::question(NULL, 
		"question", str, 
		QMessageBox::Yes | QMessageBox::No | QMessageBox::Close, 
		QMessageBox::Yes);
	if(QMessageBox::Yes == rb)
	{
		sendString = "2";
		newConnect();
	}
	else if(QMessageBox::No == rb)
	{
		sendString = "3";
		newConnect();
	}
}


//main.cpp

#include "trycli.h"
#include <QtGui/QApplication>

int main(int argc, char *argv[])
{
	QApplication app(argc, argv);
	client w;
	w.show();
	return app.exec();
}

[人到中年琐事多]

估计问题出在客户端,看看这个函数:
[code=C]/C++
void client::newConnect()
{
blockSize = 0;
tcpclient->abort();
tcpclient->connectToHost("127.0.0.1", 8888);//3
tcpclient->waitForReadyRead(); //4
}
[/code]

第3句连接成功后会产生一个connected信号,但这个信号的产生并不一定是立即的,假设这个信号还没产生,你的发送动作也必然没有产生,第4句紧接着阻塞等待读取,会有东西读到吗?
这个阻塞是必须的,但放的位置不对,应该放到啥位置? 应该放到你成功发送了数据后的地方,这时候阻塞等待服务器返回数据就应该是正确的了
成功发送数据后的地方在哪?
应该在sendMessage函数的最后,是不?
建议楼主试试,把客户端的newConnect()中的最后一条语句tcpclient->waitForReadyRead();移动到sendMessage()函数的最后.

[AAA20090987]

解决了，非常感谢你的帮助

[AAA20090987]

怎么C++的代码标签不能用了，搞到我要用JAVA的标签。。。

服务器端：

//tryser.h

#ifndef TRYSER_H_
#define TRYSER_H_

#include <QtGui/QWidget>
#include <QtGui/QLabel>
#include <QtCore/QString>
#include <QtNetwork/QTcpServer>
#include <QtNetwork/QTcpSocket>
#include <QtCore/QTimer>
#include <QtCore/QVector>

class server : public QWidget
{
	Q_OBJECT
private:
	QLabel *label;
	QString nowWord;
	QTcpServer *tcpserver;
	QTcpSocket *tcpsocket;
	quint16 blockSize;
	QString sendString;
public:
	server();
	~server();
	void sendMessage();
	public slots:
		void readMessage();
		void acceptConnection();
};

#endif


//tryser.cpp

#include "tryser.h"
#include <QtGui/QMessageBox>
#include <QtGui/QHBoxLayout>
#include <QtGui/QLabel>

server::server()
{
	label = new QLabel;
	setWindowTitle("server");
	label->setText("emtpy");
	resize(200, 100);

	QHBoxLayout *mainLayout = new QHBoxLayout;
	mainLayout->addWidget(label);
	setLayout(mainLayout);

	tcpserver = new QTcpServer;
	tcpsocket = new QTcpSocket;
	if( !tcpserver->listen(QHostAddress::Any, 8888) )
	{
		QMessageBox::warning(NULL, "error", "can not connect");
		close();
		return;
	}
	blockSize = 0;
	connect(tcpserver, SIGNAL(newConnection()), this, SLOT(acceptConnection()));

}

server::~server()
{

}

void server::acceptConnection()
{
	tcpsocket = tcpserver->nextPendingConnection();
	connect(tcpsocket, SIGNAL(readyRead()), this, SLOT(readMessage()));
	connect(tcpsocket, SIGNAL(error(QAbstractSocket::SocketError)),
		this, SLOT(displayError(QAbstractSocket::SocketError)));
}

void server::readMessage()
{
	QDataStream in(tcpsocket);
	in.setVersion(QDataStream::Qt_4_0);

	if (blockSize == 0)
	{
		if (tcpsocket->bytesAvailable() < (int)sizeof(quint16))
			return;
		in >> blockSize;
	}
	if (tcpsocket->bytesAvailable() < blockSize)
		return;
	QString word;
	in >> word;

	if("1" == word)
	{
		sendString = "Are you a boy?";
		sendMessage();
	}
	else if("2" == word)
	{
		label->setText("He is a boy");
		sendString = "Oh, you are a boy!";
		sendMessage();
	}
	else if("3" == word)
	{
		label->setText("She is a girl");
		sendString = "Oh, you are a girl!";
		sendMessage();
	}
	blockSize = 0;
}

void server::sendMessage()
{
	QByteArray block;
	QDataStream out(&block, QIODevice::WriteOnly);
	out.setVersion(QDataStream::Qt_4_0);

	out << (quint16)0;
	out << sendString;
	out.device()->seek(0);
	out << (quint16)(block.size() - sizeof(quint16));

	tcpsocket->write(block);
}



//main.cpp

#include "tryser.h"
#include <QtGui/QApplication>

int main(int argc, char *argv[])
{
	QApplication a(argc, argv);
	server w;
	w.show();
	return a.exec();
}