Own widget access causes crash

[p3t3]

Hi, I created my own widget and when I'm trying to set something inside - Qt always crash. Do you know where is the problem?

main.cpp

...

MyWidget *w1 = new MyWidget();
QString text = "text";
w1->setText(text); //this always cause crash

MyWidget *w1 = new MyWidget();
QString text = "text";
w1->setText(text); //this always cause crash

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mywidget.h

#ifndef MYWIDGET_H
#define MYWIDGET_H
 
#include <QWidget>
#include <QLabel>
#include <QGridLayout>
 
class MyWidget : public QWidget
{
    Q_OBJECT
public:
    explicit MyWidget(QWidget *parent = 0);
    void SetText(QString text);
 
signals:
 
public slots:
 
private:
    QLabel *label1;
};

#ifndef MYWIDGET_H
#define MYWIDGET_H

#include <QWidget>
#include <QLabel>
#include <QGridLayout>

class MyWidget : public QWidget
{
    Q_OBJECT
public:
    explicit MyWidget(QWidget *parent = 0);
    void SetText(QString text);

signals:

public slots:

private:
    QLabel *label1;
};

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mywidget.cpp

include "mywidget.h"
 
MyWidget::MyWidget(QWidget *parent) :
    QWidget(parent)
{
    QGridLayout *layout = new QGridLayout();
    QLabel *label1 = new QLabel("Name");
    layout->addWidget(label1, 0, 0);
    setLayout(layout);
}
 
void MyWidget::setText(QString text) {
    label1->setText(text);
}

include "mywidget.h"

MyWidget::MyWidget(QWidget *parent) :
    QWidget(parent)
{
    QGridLayout *layout = new QGridLayout();
    QLabel *label1 = new QLabel("Name");
    layout->addWidget(label1, 0, 0);
    setLayout(layout);
}

void MyWidget::setText(QString text) {
    label1->setText(text);
}

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[wysota]

In line #7 of your last snippet you are creating a local variable "label1" which shadows the class member variable "label1" thus the latter remains uninitialized and crashes your program when you try to dereference it.