Question

In CSharp it’s as simple as writing:

listBox1.Items.Add("Hello");
listBox1.Items.Add("There");

foreach (string item in listBox1.Items )
{
    MessageBox.Show(item.ToString());
}

and I can easily add different objects to a list box and then retrieve them using foreach.

I tried the same approach in Qt 4.8.2 but it seems they are different. Though they look very similar at the first. I found that Qt supports foreach so I went on and tried something like:

foreach(QListWidgetItem& item,ui->listWidget->items())
{
    item.setTextColor(QColor::blue());
}

which failed clearly. It says the items() needs a parameter which confuses me. I am trying to iterate through the ListBox itself, so what does this mean? I tried passing the ListBox object as the parameter itself this again failed too:

foreach(QListWidgetItem& item,ui->listWidget->items(ui->listWidget))
{
    item.setTextColor(QColor::blue());
}

So here are my questions:

• How can I iterate through a QListWidget items in Qt?
• Can I store objects as items in QListWidgets like C#?
• How can I convert an object in QListWidgets to string (C#s ToString counter part in Qt) ?

(Suppose I want to use a QMessageBox instead of that setTextColor and want to print out all string items in the QlistWidget.)

Answer 1

I don’t think the items function does what you think it does. It sounds like it’s for decoding MIME data, not getting a list of all the items in the widget.

I don’t actually see any function to do exactly what you want, sadly. You could probably use findItems as a workaround, but that seems ugly, if not downright abusive… At least you can still use the item function with good old for loops – they’re not that much more typing:

for(int i = 0; i < listWidget->count(); ++i)
{
    QListWidgetItem* item = listWidget->item(i);
    //Do stuff!
}

Hope that helps!