How can I convert a char to QString?

Question

Well this proves I'm a noob at coding! I've looked everywhere and still can't get this right. This should be pretty simple.

I have been trying this:

int i;
for(i=0;i<16;i++)
{
  QChar q = QChar(memblock[i]);
  QString s = QString(q);
  QTableWidgetItem *item = new QTableWidgetItem(s);
  ui->tableWidget->setItem(rowCount, colCount, item);
}

So I'm making table items from each string. That's because I also couldn't figure out how to make table items from just a QChar, or plain char.

But each cell ends up with:

Ý

Whereas when I add in:

cout << memblock[i];

It properly shows:

RIFFd2  WAVEfmt

Here is the code that reads in the raw data:

ifstream file (text, ios::in|ios::binary|ios::ate);
if (file.is_open())
{
    size = file.tellg();
    memblock = new char [size];
    file.seekg(0, ios::beg);
    file.read(memblock, size);
    file.close();
}

Also, when I do cout << &memblock[i], for i from 0 to 4 I get: RIFFd2 IFFd2 FFd2 Fd2

And so on.

Could you add to the post the code which initializes the `memblock` variable — Ivan, Jun 19 '13 at 16:11
Honestly, it should be as simple as `QTableWidgetItem item = new QTableWidgetItem(memblock[i]);` — krb686, Jun 19 '13 at 16:20
it may hardly be shorter than this - `QTableWidgetItem *item = new QTableWidgetItem(QChar(memblock[i]));` — Ivan, Jun 19 '13 at 16:44
may be you should use an array of `QString` or `QChar` instead of raw chars — Ivan, Jun 19 '13 at 16:54
I added the line `qDebug() << item` , which puts out: `0x5a4fe20 0x5a50130 0x5a50210 0x5d2bb40 0x5d2b4b0 0x5d2ba60 0x5d2b750 0x5c76b80 0x5c76e20 0x5c76bf0 0x5c76950 0x5c76b10 0x5c76cd0 0x6f425e0 0x6f42810 0x6f42650 ` Looks like the memory address of each char, which would make me think I could just change it to *memblock[i] to dereference and retrieve the real value, but doing so gives the error : `illegal indirection` — krb686, Jun 19 '13 at 16:56
I thought about doing that, but I decided on using Qt only for GUI aspects since I have almost no experience/knowledge of c++. One of my main goals is to learn c++. Similar to this guy: http://programmers.stackexchange.com/questions/195568/qt-c-vs-generic-c-and-stl — krb686, Jun 19 '13 at 17:11

Ivan · Accepted Answer · 2013-06-19T18:17:18.167

3

I've managed to use some simplified variant of your code with Qt 4.8.3 and MSVC 2010:

ui.tableWidget->setColumnCount(5);
ui.tableWidget->setRowCount(5);
char *memChunck = new char[25];
for ( int i = 0; i < 25; ++i ) {
    memChunck[i] = i + 65;
}
for ( int i = 0; i < 25; ++i ) {
    QTableWidgetItem *item = new QTableWidgetItem(QString::number( memChunck[i], 16).toUpper() );
    ui.tableWidget->setItem(i / 5, i % 5, item);
}

result view

edited Jun 19 '13 at 18:17

answered Jun 19 '13 at 17:34

Ivan

588
5
20

Okay that seems fairly similar to what I have. I may have somewhat misstated my intention though. I don't actually want Ascii representation of my data, I want the raw data as a string. So in other words, I want 65, 66, 67, 68, and so on. What I really want is this: http://imgur.com/QtaspOK – krb686 Jun 19 '13 at 17:58
@krb686, just changed the code. On updated screenshot I've used data for table from the link you provided. – Ivan Jun 19 '13 at 18:19
I changed my code to match yours exactly, but it's not quite there for some reason. This is what it looks like after the change: http://imgur.com/tsJ2e22 I think this may have something to do with my `memblock` I updated my original post showing the code I am using to read in raw data. – krb686 Jun 19 '13 at 18:24
@krb686, yeah, it seems to me that the reason is how your `memblock` is initialized. Try to read your input file as text rather than as binary. – Ivan Jun 19 '13 at 18:42
I got it working! Your code works perfectly actually. I forgot I pasted the reading data section in from another file that also included `delete[] memblock;` before I started trying to make items from the memblock. doh! – krb686 Jun 19 '13 at 18:56

How can I convert a char to QString?

1 Answers1