How QFile can read/write 8 different outputs/inputs using for loop.

Mijaz

I will give inputs at Run-time from GUI LineEdit, as follows

Take input from these lineEdits:

ui->lineEdit_1->text();
ui->lineEdit_2->text();
ui->lineEdit_3->text();
ui->lineEdit_4->text();
ui->lineEdit_5->text();
ui->lineEdit_6->text();
ui->lineEdit_7->text();
ui->lineEdit_8->text();

Take outputs from these lineEdits;
ui->lineEdit_11->text();
ui->lineEdit_12->text();
ui->lineEdit_13->text();
ui->lineEdit_14->text();
ui->lineEdit_15->text();
ui->lineEdit_16->text();
ui->lineEdit_17->text();
ui->lineEdit_18->text();

My Target:
// I want to update same register(out_altvoltage1_TX_LO_frequency) for 8 different inputs (lineEdit_1 to 8) and display outputs in 8 different lineEdits(11 to 18) accordingly.

// for single operation code is given below which is working correctly.

ui->lineEdit_1->text();
//write value
QFile f1("/sys/bus/iio/devices/iio:device1/out_altvoltage1_TX_LO_frequency");
if (f1.open(QIODevice::WriteOnly | QIODevice::Text)) {
f1.write(ui->lineEdit_1->text().toLatin1());
f1.close();
}
//read value
QFile f("/sys/bus/iio/devices/iio:device1/out_altvoltage1_TX_LO_frequency");
if (f.open(QIODevice::ReadOnly | QIODevice::Text))
{
QByteArray ba = f.readAll();
ui->lineEdit_11->setText(QString(ba));
f.close();
}

jsulm

@Mijaz said in How QFile can read/write 8 different outputs/inputs using for loop.:

for single operation code is given below which is working correctly.

And what exactly is the problem putting this code into a loop? If you can do it for one you can do it for many. Please at least try to put it in a loop by yourself.

Mijaz

This post is deleted!

jsulm

@Mijaz The code you posted does not make any sense!
QFile opens a file (file path as string) not an integer!
You don't have to open the file inside the loop!
Even your for loops are wrong - you should learn C++.
PLEASE post your code as TEXT and not scrennshots!
It's really not that hard:

QFile f("HERE YOUR PATH");
if (f.open(...)) {
    for (int i = 0; i < 9; ++i) {
        f.write(...);
    }
    f.close();
}

JonB

@Mijaz
@jsulm's comment above is the most important.

But what are the 16 statements like ui->Pro1_Freq->text() doing? What do they achieve? The text() method returns the text, so these statements are pointless, and I don't know what you intend them for. If I didn't know better, I'd wonder if they are all supposed to be setText(""), but who knows....

J.Hilk

@Mijaz

because it pains my soul:

but it sill makes little sense to me.
What are you actually trying to do?

//Inputs
   const QVector<QLabel*> inputs{
                ui->Pro1_Freq,
                ui->Pro2_Freq,
                ui->Pro3_Freq,
                ui->Pro4_Freq,
                ui->Pro5_Freq,
                ui->Pro6_Freq,
                ui->Pro7_Freq,
                ui->Pro8_Freq,
                ui->Pro9_Freq
    };
    // for outputs
   const QVector<QLabel*> outputs{
        ui->Pro1_status,
        ui->Pro2_status,
        ui->Pro3_status,
        ui->Pro4_status,
        ui->Pro5_status,
        ui->Pro6_status,
        ui->Pro7_status,
        ui->Pro8_status
    };

    QFile f("/sys/bus/iio/devices/iio:device1/out_altvoltage1_TX_LO_frequency");
    if (f.open(QIODevice::WriteOnly | QIODevice::Text)) {
        for(QLabel *l : inputs) {
                f.write(l->text().toLatin1());
        }
    }
    f.close();

    //this makes little sense, but it is, what you wrote
    f.setFileName("/sys/bus/iio/devices/iio:device1/out_altvoltage1_TX_LO_frequency");
    if (f.open(QIODevice::ReadOnly | QIODevice::Text)) {
        for(QLabel *l : outputs) {
                l->setText(f.readAll());
                l->setStyleSheet("background-color: rgb(0,0,0)");
        }
    }
    
    f.close();

JonB

@J-Hilk
Above your second loop, I think you mean QIODevice::ReadOnly rather than QIODevice::WriteOnly.

J.Hilk

@JonB absolutely, copy past error, also missed a ;

mrjj

@J-Hilk
Thanks it hurt my soul too :)