[How to ?] Writing QTableWidget cells.

[Rewo]

Hi, I've done reading from QTableWidget cells:

QTableWidgetItem *itab = tableWidget->item(0,0);
QString itabtext = itab->text();

QTableWidgetItem *itab = tableWidget->item(0,0);
QString itabtext = itab->text();

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But i tried to make writing to QTableWidget cells:

I tried many ways, for example:

_____

Code:

QTableWidgetItem *itab;
itab->setText("X");
tableWidget->setItem(0, 0, itab);

QTableWidgetItem *itab;
itab->setText("X");
tableWidget->setItem(0, 0, itab);

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Result (during running the program (compilation OK)):



_____

Code:

QTableWidgetItem *itab;
itab->setText("X");   
tableWidget->setItem(0, 0, itab->text());

QTableWidgetItem *itab;
itab->setText("X");   
tableWidget->setItem(0, 0, itab->text());

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Result (during compilation):



Of course it's logical, because setItem needs QTableWidgetItem as third parameter, unfortunately not QString .

Can someone help me how to write "X" into (0,0) cell ?

[SteveH]

Hi,

QTableWidgetItem *twi ;
twi= tableWidget->item(row, col) ;
twi->setText(QString) ;

SteveH

[Rewo]

Thanks for reply.

I did that:

Code:

QTableWidgetItem *itab;
itab = tableWidget->item(0,0);
itab->setText("X");

QTableWidgetItem *itab;
itab = tableWidget->item(0,0);
itab->setText("X");

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Result (during running the program (compilation OK)):




Program works correctly when I delete "itab->setText("X");", but without any result, ofc.
Program works correctly too when I delete "itab = tableWidget->item(0,0);", so this 2 lines collide.

EDIT:

I tried this:

Code:

QTableWidgetItem *itab;
itab->text() = "X";
tableWidget->setItem(0, 0, itab);

QTableWidgetItem *itab;
itab->text() = "X";
tableWidget->setItem(0, 0, itab);

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And this:

Code:

QTableWidgetItem *itab;
itab->text() = "X";
tableWidget->item(0,0);

QTableWidgetItem *itab;
itab->text() = "X";
tableWidget->item(0,0);

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But the result is:





EDIT XXX:

It's very very funny, look:

QTableWidgetItem *itab;
itab->text() = "X";
QString cyce = itab->text();
label -> setText(cyce);

QTableWidgetItem *itab;
itab->text() = "X";
QString cyce = itab->text();
label -> setText(cyce);

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OR

QTableWidgetItem *itab;
itab -> setText("X");
QString cyce = itab->text();
label -> setText(cyce);

QTableWidgetItem *itab;
itab -> setText("X");
QString cyce = itab->text();
label -> setText(cyce);

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And the result is of course:





Dunno. It looks like setText and itab->text() = "X"; are wrong here.

[john_god]

You have to alocate memory to your pointer

QTableWidgetItem *itab;
itab = new QTableWidgetItem; // add this line 
itab->setText("X");   
tableWidget->setItem(0, 0, itab);

QTableWidgetItem *itab;
itab = new QTableWidgetItem; // add this line 
itab->setText("X");   
tableWidget->setItem(0, 0, itab);

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It was crashing because you're setting a value to an unalolocate pointer.

[norobro]

I noticed john_god's post right after I pressed "Submit Reply"

Try this:

QTableWidgetItem *itab= new QTablewidgetItem;
itab->setText("X");   
tableWidget->setItem(0, 0, itab);

QTableWidgetItem *itab= new QTablewidgetItem;
itab->setText("X");   
tableWidget->setItem(0, 0, itab);

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[Rewo]

Thanks, it helped. But I have one more problem.

I tried to apply that:

QTableWidgetItem *itab = new QTableWidgetItem;
itab -> setText("X");
for(int a=0;a<irows;a++)
     for(int b=0;b<icols;b++) {
         tableWidget->setItem(a, b, itab);
     }

QTableWidgetItem *itab = new QTableWidgetItem;
itab -> setText("X");
for(int a=0;a<irows;a++)
     for(int b=0;b<icols;b++) {
         tableWidget->setItem(a, b, itab);
     }

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Filling "X" works only for (0,0) cell, while running program, there is statement in compiling console:

"QTableWidget: cannot insert an item that is already owned by another QTableWidget"

If I have 4x3 table, this statement appears 4x3-1=11 times.

I tried to make an "itab" array, but it failed.

I think that itab needs some release from cell, but dunno how to do that.

________

EDIT 2 minutes later:

I did that:

for(int a=0;a<irows;a++)
        for(int b=0;b<icols;b++) {
            QTableWidgetItem *itab = new QTableWidgetItem;
            itab -> setText("X");
            tableWidget->setItem(a, b, itab);
        }

for(int a=0;a<irows;a++)
        for(int b=0;b<icols;b++) {
            QTableWidgetItem *itab = new QTableWidgetItem;
            itab -> setText("X");
            tableWidget->setItem(a, b, itab);
        }

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And it works for me .

[john_god]

Please let me make a sugestion, if you plan to fill the table more than once, use the following code to avoid duplicating items

for(int a=0;a<irows;a++)
    for(int b=0;b<icols;b++){
 
    if (tableWidget->itab(a,b) == 0)
    {
        QTableWidgetItem *itab = new QTableWidgetItem;
        itab->setText("X");
        tableWidget->setItem(a,b, itab);
    }
    else
    {
        tableWidget->item(a, b)->setText("X");
    }
 
}

for(int a=0;a<irows;a++)
    for(int b=0;b<icols;b++){

    if (tableWidget->itab(a,b) == 0)
    {
        QTableWidgetItem *itab = new QTableWidgetItem;
        itab->setText("X");
        tableWidget->setItem(a,b, itab);
    }
    else
    {
        tableWidget->item(a, b)->setText("X");
    }

}

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