Errors while compiling a test program using Qt

Question

I am pretty new to C++/Qt I am following the book 'C++ GUI Programming with Qt 4' by Jasmin Blanchette and Mark Summerﬁeld. I was working on an example program and got stuck up with some compilation errors which I was not able to resolve. Code and Errors below. Any help is appreciated. Thanks. finddialog.h ``` #ifndef FINDDIALOG_H #define FINDDIALOG_H #include class QCheckBox; class QLabel; class QLineEdit; class QPushButton; class QWidget; class FindDialog : QDialog { Q_OBJECT public: FindDialog(QWidget *parent = 0); signals: void findNext(const QString &str, Qt::CaseSensitivity cs); void findPrevious(const QString &str, Qt::CaseSensitivity cs); private slots: void findClicked(); void enableFindButton(const QString &text); private: QLabel *label; QLineEdit *lineEdit; QCheckBox *caseCheckBox; QCheckBox *backwardCheckBox; QPushButton *findButton; QPushButton *closeButton; }; #endif // FINDDIALOG_H ``` finddialog.cpp ``` #include #include "finddialog.h" FindDialog::Fin…

Accepted Answer

You should inherit publically from `QWidget` or `QDialog`:

```
 class FindDialog : public QDialog {
      // ...
```

`show()` is actually implemented by a base of `FindDialog`, `QWidget` - but you are not inheriting publically from it and thus can't access it.

Inheritance for classes is by default private, i.e.

```
class A : B {}; 
```

and

```
class A : private B {};
```

are equivalent.

Errors while compiling a test program using Qt

Solution

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