how to update QTableWidget item? - qt

Question

There is a thread running! it receives data from internet two times per second, then I set the data in qtablewidget?
How can I make the QTableWidget update itself ?
Now I must click the interface if I want to update the display!
DWORD WINAPI MyThreadProc1(LPVOID lpParameter){
int data=receive();
w.setVal(data);
return 0;
}
void TradeSystem::setValue(int num){
QTableWidgetItem *item = new QTableWidgetItem(QString::number(num,10,1));
item->setBackgroundColor(QColor(0,60,10));
ui.tableWidget_3->item(0,0)->setText(QString::number(num,10,0));
}

Answer 1

i guess this problem falls in the category 'i want to change gui from another thread' -> don't do it.
when setValue(int) is a slot, you can do the following:
DWORD WINAPI MyThreadProc1(LPVOID lpParameter)
{
(void)lpParameter;
int data = receive();
QMetaObject::invokeMethod(w, "setValue", Q_ARG(int, data));
}

Answer 2

You should get used to signals in QT , its easy to use and can make your life easier .
DWORD WINAPI MyThreadProc1(LPVOID lpParameter){
int data=receive();
emit data_recieved(data);
return 0;
}
void TradeSystem::setValue(int num){
QTableWidgetItem *item = new QTableWidgetItem(QString::number(num,10,1));
item->setBackgroundColor(QColor(0,60,10));
ui.tableWidget_3->item(0,0)->setText(QString::number(num,10,0));
}
and before you activate MyThreadProc1 , connect the signal and handler :
connect(this,SLOT(setValue(int)),MyThreadProc1,SIGNAL(data_recieved(int)));
that way , you can connect basically every widget in qt with a signal/slot .
either in different Form,Threads .
This is helpful also Docs.