Naming columns for QTableWidget

[Swati777999]

Hi All ,

How to give names for columns of QTableWidge types?
Below is my attempt but it crashed, I know I am not using myTable->horizontalHeaderItem(1)->setText("Name"); correctly.

{
    QTableWidget *myTable = new QTableWidget(this);
    myTable ->setRowCount(7);
    myTable->setColumnCount(3);
    myTable->verticalHeader()->hide();
    myTable->horizontalHeader()->hide();

   myTable->horizontalHeaderItem(1)->setText("S.No");
   myTable->horizontalHeaderItem(1)->setText("Date");
   myTable->horizontalHeaderItem(1)->setText("Name");
   this->show();
}

[AxelVienna]

Which Qt version are you working with? The line I suggested works just fine on Qt 6.2.2.
Your experiments create a QStringList object on the heap. Why? Sub-sequentially you treat name as an instance while it is a pointer. This just goes nowhere.
You will find all constructors and examples here.

Corrected versions of your experiments are:

Trial 1:
QStringList name;
name << "S.No" << "Date" << "Name";
myTable->setHorizontalHeaderLabels(name); // no more error:

Trial 2
const QStringList name = {"S. No","Date","Name"};
myTable->setHorizontalHeaderLabels(name); //no more error:

[Christian Ehrlicher]

@Swati777999 said in Naming columns for QTableWidget:

myTable->horizontalHeaderItem(1)->setText("S.No");
myTable->horizontalHeaderItem(1)->setText("Date");
myTable->horizontalHeaderItem(1)->setText("Name");

Please read again... how should this set different header columns?

Also you should check if myTable->horizontalHeaderItem(1) returns a valid pointers

[anil_arise]

@Swati777999 said in Naming columns for QTableWidget:

QTableWidget default set QHeaderView not any QTableWidgetItem (~ nullptr). So First set horizontalHeaderItem :
Example :
QTableWidget *myTable = new QTableWidget(this);
myTable ->setRowCount(7);
myTable->setColumnCount(3);
QTableWidgetItem *hItem0 = new QTableWidgetItem("S. No");
myTable->setHorizontalHeaderItem(0,hItem0);
QTableWidgetItem *hItem1 = new QTableWidgetItem("Date");
myTable->setHorizontalHeaderItem(1,hItem1);

another way is set Header Label
Example:
QTableWidget *myTable = new QTableWidget(this);
myTable ->setRowCount(7);
myTable->setColumnCount(3);
myTable->setHorizontalHeaderLabels({"S. No","Date","Name"});

Now you can access Header item for modify
myTable->horizontalHeaderItem(column_Count)->setText("xyz---");

[Swati777999]

@Christian-Ehrlicher said in Naming columns for QTableWidget:

@Swati777999 said in Naming columns for QTableWidget:

myTable->horizontalHeaderItem(1)->setText("S.No");
myTable->horizontalHeaderItem(1)->setText("Date");
myTable->horizontalHeaderItem(1)->setText("Name");

Please read again... how should this set different header columns?

OOPS.... I forgot to change the indices of these names, actually, I intended to write the following codes-

myTable->horizontalHeaderItem(0)->setText("S.No");
myTable->horizontalHeaderItem(1)->setText("Date");
myTable->horizontalHeaderItem(2)->setText("Name");

Also you should check if myTable->horizontalHeaderItem(1) returns a valid pointers

[Swati777999]

@anil_arise said in Naming columns for QTableWidget:

@Swati777999 said in Naming columns for QTableWidget:

QTableWidget default set QHeaderView not any QTableWidgetItem (~ nullptr). So First set horizontalHeaderItem :
Example :
QTableWidget *myTable = new QTableWidget(this);
myTable ->setRowCount(7);
myTable->setColumnCount(3);
QTableWidgetItem *hItem0 = new QTableWidgetItem("S. No");
myTable->setHorizontalHeaderItem(0,hItem0);
QTableWidgetItem *hItem1 = new QTableWidgetItem("Date");
myTable->setHorizontalHeaderItem(1,hItem1);

another way is set Header Label

QTableWidget *myTable = new QTableWidget(this);
myTable ->setRowCount(7);
myTable->setColumnCount(3);
myTable->setHorizontalHeaderLabels({"S. No","Date","Name"});

Now you can access Header item for modify
myTable->horizontalHeaderItem(column_Count)->setText("xyz---");

As suggested by you,
METHOD-1

{
QTableWidget *myTable = new QTableWidget(7,3,this);
myTable->horizontalHeader()->hide();
QTableWidgetItem *hItem0 = new QTableWidgetItem("S. No");
myTable->setHorizontalHeaderItem(0,hItem0);
QTableWidgetItem *hItem1 = new QTableWidgetItem("Date");
myTable->setHorizontalHeaderItem(1,hItem1);
this->show();
setWindowTitle(tr("TableWidget Example"));
}

Result : No headings appeared.

METHOD-2
I tried the following code

QTableWidget *myTable = new QTableWidget(7,3,this);
myTable->horizontalHeader()->hide();
 myTable->setHorizontalHeaderLabels({"S. No","Date","Name"}); // Error : No matching constructor initialisation
 this->show();
setWindowTitle(tr("TableWidget Example"));

[AxelVienna]

Method 1 does not set any headers. It populates the first row with what you want to be your header.
Method 2 goes in the right direction but it hides the headers you want to display. You need to delete line 2 of your code completely if you want your headers to be shown.

setHorizontalHeaderLables expects a QStringList as an argument. Your argument is ambiguous, that's why you get an error. Replace your line with:

myTable->setHorizontalHeaderLabels(QStringList({"S. No","Date","Name"}));

...and your error disappears.

BTW: this->show() is strange by itself and even stranger as you call setWindowTitle() afterwards.

[Swati777999]

@AxelVienna said in Naming columns for QTableWidget:

Method 1 does not set any headers. It populates the first row with what you want to be your header.
Method 2 goes in the right direction but it hides the headers you want to display. You need to delete line 2 of your code completely if you want your headers to be shown.

setHorizontalHeaderLables expects a QStringList as an argument. Your argument is ambiguous, that's why you get an error. Replace your line with:

myTable->setHorizontalHeaderLabels(QStringList({"S. No","Date","Name"}));

...and your error disappears.

BTW: this->show() is strange by itself and even stranger as you call setWindowTitle() afterwards.

Yes, I had already tried with this line

myTable->setHorizontalHeaderLabels(QStringList({"S. No","Date","Name"})); which gives me an error as no matching constructor for initialisation of QStringList.

I tried experimenting as below:
Trial-1

QStringList *name = new QStringList();
name << "S.No" << "Date" << "Name";
myTable->setHorizontalHeaderLabels(name); // Error:

Trial-2

QStringList *name = new QStringList();
name = {"S. No","Date","Name"};
myTable->setHorizontalHeaderLabels(name); //Error:

Any suggestion?

[Christian Ehrlicher]

And again basic c++ knowledge missing. setHorizontalHeaderLabels() takes a QStringList, not a pointer to a QStringList. So why are you creating a pointer to a QStringList and try to pass it to setHorizontalHeaderLabels()?

[AxelVienna]

Which Qt version are you working with? The line I suggested works just fine on Qt 6.2.2.
Your experiments create a QStringList object on the heap. Why? Sub-sequentially you treat name as an instance while it is a pointer. This just goes nowhere.
You will find all constructors and examples here.

Corrected versions of your experiments are:

Trial 1:
QStringList name;
name << "S.No" << "Date" << "Name";
myTable->setHorizontalHeaderLabels(name); // no more error:

Trial 2
const QStringList name = {"S. No","Date","Name"};
myTable->setHorizontalHeaderLabels(name); //no more error:

[Swati777999]

@AxelVienna said in Naming columns for QTableWidget:
Which Qt version are you working with? The line I suggested works just fine on Qt 6.2.2.
I am working with Qt 4.8

Your experiments create a QStringList object on the heap. Why? Sub-sequentially you treat name as an instance while it is a pointer. This just goes nowhere.
You will find all constructors and examples here.

Corrected versions of your experiments are:

Trial 1:
QStringList name;
name << "S.No" << "Date" << "Name";
myTable->setHorizontalHeaderLabels(name); // no more error:

Trial 2
QStringList name = {"S. No","Date","Name"};
myTable->setHorizontalHeaderLabels(name); //no more error:

In Your Version of codes
In Trial 1 : No headings appear ; only the table with rows and column
In Trial 2: Error in QStringList name = {"S. No","Date","Name"}; --> Error : No matching constructor for initialisation of 'QStringList'

[AxelVienna]

Trial 1 does not display anything because you hide your headers explicitly. Read my previous post and remove the respective line.
Trial 2 fails because you use Qt 4.8.

[Swati777999]

@AxelVienna said in Naming columns for QTableWidget:
Trial 1 does not display anything because you hide your headers explicitly. Read my previous post and remove the respective line.
I thought myTable->horizontalHeader()->hide(); for hiding numerical headers.

Trial 2 fails because you use Qt 4.8.
Got it.

It works like a charm!