How Can i get array in another class

dziko147

to resume what should i do to set data from GUI element in an array then get this array in another class .

Btw I tried many solution but usually I get an empty array in the other class :)

jsulm

@dziko147 said in How Can i get array in another class:

but usually I get an empty array in the other class

I guess that's because you have more than one instance of the class from which you get your array.
Please post your code. Passing data from one object to another is actually a trivial exercise.

dziko147

@jsulm

// classeA.h
std::array<QString,25> Inputs;

// ClassA.cpp "UploadCSV"
void UploadCSV::on_parambtn_2_clicked()
{

    int compteur=0;
    QString cell0;
    QString cell3 ;
    for(int i=0;i<ui->tablewidget->rowCount();i++){

        QTableWidgetItem *cell7 = ui->tablewidget->item(i,7);

        QVariant myData7 = cell7->data(Qt::DisplayRole);
        if (myData7=="Core_meas"){
            cell0  = ui->tablewidget->item(i,0)->text();
            cell3 = ui->tablewidget->item(i,3)->text();
            Inputs[compteur]=cell3;
            qDebug() << "Inputs baby"<<Inputs[compteur] ;
            compteur++;
        }

    }


}

//in classB.

UploadCSV *up;

//in classB.cpp

up=new UploadCSV();
for(size_t i=0;i<up.Inputs->size();i++){
qqDebug() << "this is data",up.Inputs[i]

jsulm

@dziko147 Sorry, I fail to understand the code you posted.
What type is myclasseA? And why do you access Inputs from two different objects (up and myclasseA)?
It really looks like you have two different instances of UploadCSV...

Pl45m4

@dziko147 said in How Can i get array in another class:

,myclasseA.Inputs[i]

Why do you have myClasseA there, when the object is up
Try up.Inputs[i]

(Corrected, thx @jsulm )

jsulm

@Pl45m4 said in How Can i get array in another class:

when the object is UploadCSV

UploadCSV seems to be the class, not object

dziko147

@jsulm sorry I edited the code .

I gave the expamle of classA and ClassB to be clearer .

ClassA (UploadCSV ) is a Qwidget : Qdialog

ClassB (Backend) is QObject .

CP71

@dziko147 said in How Can i get array in another class:

up=new UploadCSV();
for(size_t i=0;i<up.Inputs->size();i++){
qqDebug() << "this is data",up.Inputs[i]

Sorry, who calls the on_parambtn_2_clicked() function?

jsulm

@dziko147 Is this your real code:

up=new UploadCSV();
for(size_t i=0;i<up.Inputs->size();i++){
qqDebug() << "this is data",up.Inputs[i]

?
Because Items is filled when UploadCSV::on_parambtn_2_clicked() is called (at least according to code you posted). But you're printing Inputs just after creating UploadCSV instance (up)! So why should there be anything in Inputs?

dziko147

@CP71 it's called in UploadCSV class (classA) .

and inside this function I set data in Inputs[] .

jsulm

@dziko147 said in How Can i get array in another class:

it's called in UploadCSV class (classA) .

Where exactly?! And what is classA?! This all is really confusing!
up != classA

dziko147

@jsulm yes i understand you . So can you suggest a way to do this correctly ?

jsulm

@dziko147 Yes, I can: use one instance of the class instead of two...

SGaist

@dziko147 said in How Can i get array in another class:

@jsulm yes i understand you . So can you suggest a way to do this correctly ?

Something like it was explained in your other thread ?

dziko147

@jsulm forget classA and classB example .

So curretly we have UploadCSV class and BackendClass .
I would like to get array defined from UploadCSV in Backend class .

jsulm

@dziko147 said in How Can i get array in another class:

I would like to get array defined from UploadCSV in Backend class

Then do so.
To get it you need the UploadCSV instance. How you get it in Backend I don't know as I don't have your code. There are different ways to do this. You can pass pointer to UploadCSV instance to Backend constructor for example.
But to be able to give a good advice we would need to know how you manage your UploadCSV and Backend instances.

dziko147

@jsulm
currently I pass a pointer like this .
in backend.h

UploadCSV *up;

in backend.cpp

up = new UploadCSV();

CP71

@dziko147
Here you are not passing a pointer but you are creating a new instance of class

CP71

@dziko147
Sorry, but my English is no good.
So maybe I can help you with an example.

To link my example.
I think you are filling your array in obj1, but when you try to read it you use obj2.
You that know your project, have a sense what I write?

In short, these are possible ways to have your result:

two or more instance of you class
your object never fills the array
your object fills the array but with an empty value
in somewhere of your class clear your array before you use it

But in your case seems you have two instances of class

Pl45m4

@dziko147

Now that I understand a bit more, I think the only issue here is that you dont click that button that will fill your array before you try to access the elements.

You fill your array here:

void UploadCSV::on_parambtn_2_clicked()
{
....
if (myData7=="Core_meas"){
            cell0  = ui->tablewidget->item(i,0)->text();
            cell3 = ui->tablewidget->item(i,3)->text();
            Inputs[compteur]=cell3;  //  <---- HERE
            qDebug() << "Inputs baby"<<Inputs[compteur] ;
            compteur++;
        }
....

}

That means the array is still empty right after creating the class instance.

up=new UploadCSV(); // <--- New, empty public array
for(size_t i=0;i<up.Inputs->size();i++){
qDebug() << "this is data",up.Inputs[i] // data access, but not clicked that button before

Also, you need to have access to the "same" instance where your array is filled with data. (See @CP71 and @jsulm answers). This could be done by passing a pointer to that object with contains your data.