Hi everybody
I have created a widget with the designer. Now i am trying to subclass it like the doc, i get following error by compiling. Can somebody see the problem?
main.cpp
Qt Code: 
  1. #include <QApplication>
  2. #include "dialog.h"
  3.  
  4. int main(int argc, char *argv[])
  5. {
  6.     QApplication app(argc, argv);
  7.  
  8.     Dialog dialog;
  9.     dialog.show();
  10.     return app.exec(); 
  11. }
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dialog.h
Qt Code: 
  1. #include "ui_widget1.h"
  2.  
  3.  
  4. class Dialog : public QDialog
  5. {
  6.     Q_OBJECT
  7.  
  8.     public:
  9.     	Dialog(QWidget *parent = 0);
  10.  
  11.     private:
  12.     	Ui::Dialog ui;
  13. };
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dialog.cpp
Qt Code: 
  1. #include "dialog.h"
  2.  
  3. Dialog::Dialog(QWidget *parent)
  4.     : QDialog(parent)
  5. {
  6. 	ui.setupUi(this);
  7.  
  8. }
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ui_widget1.h
Qt Code: 
  1. #ifndef UI_WIDGET1_H
  2. #define UI_WIDGET1_H
  3.  
  4. #include <QtCore/QVariant>
  5. #include <QtGui/QAction>
  6. #include <QtGui/QApplication>
  7. #include <QtGui/QButtonGroup>
  8. #include <QtGui/QPushButton>
  9. #include <QtGui/QWidget>
  10.  
  11. class Ui_Widget1
  12. {
  13. public:
  14.     QPushButton *btn1;
  15.     QPushButton *btn1_2;
  16.  
  17.     void setupUi(QWidget *Widget1)
  18.     {
  19.     Widget1->setObjectName(QString::fromUtf8("Widget1"));
  20.     Widget1->resize(QSize(181, 101).expandedTo(Widget1->minimumSizeHint()));
  21.     btn1 = new QPushButton(Widget1);
  22.     btn1->setObjectName(QString::fromUtf8("btn1"));
  23.     btn1->setGeometry(QRect(50, 40, 75, 24));
  24.     btn1_2 = new QPushButton(Widget1);
  25.     btn1_2->setObjectName(QString::fromUtf8("btn1_2"));
  26.     btn1_2->setGeometry(QRect(100, 70, 75, 24));
  27.     retranslateUi(Widget1);
  28.  
  29.     QMetaObject::connectSlotsByName(Widget1);
  30.     } // setupUi
  31.  
  32.     void retranslateUi(QWidget *Widget1)
  33.     {
  34.     Widget1->setWindowTitle(QApplication::translate("Widget1", "Ich bin ein Widget", 0, QApplication::UnicodeUTF8));
  35.     btn1->setText(QApplication::translate("Widget1", "Show Message", 0, QApplication::UnicodeUTF8));
  36.     btn1_2->setText(QApplication::translate("Widget1", "Show Message", 0, QApplication::UnicodeUTF8));
  37.     Q_UNUSED(Widget1);
  38.     } // retranslateUi
  39.  
  40. };
  41.  
  42. namespace Ui {
  43.     class Widget1: public Ui_Widget1 {};
  44. } // namespace Ui
  45.  
  46. #endif // UI_WIDGET1_H
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ERROR:
Qt Code: 
  1. dialog.h:5: error: invalid use of undefined type `struct QDialog'
  2. D:/apps/Qt/4.1.3/include/QtGui/../../src/gui/kernel/qwindowdefs.h:38: error: for
  3. ward declaration of `struct QDialog'
  4. dialog.h:12: error: using-declaration for non-member at class scope
  5. dialog.h:12: error: expected `;' before "ui"
  6. In file included from dialog.cpp:1:
  7. dialog.h:13:3: warning: no newline at end of file
  8. dialog.cpp: In constructor `Dialog::Dialog(QWidget*)':
  9. dialog.cpp:4: error: type `struct QDialog' is not a direct base of `Dialog'
  10. dialog.cpp:6: error: `ui' undeclared (first use this function)
  11. dialog.cpp:6: error: (Each undeclared identifier is reported only once for each
  12. function it appears in.)
  13. dialog.cpp:8:2: warning: no newline at end of file
  14. mingw32-make[1]: *** [release\dialog.o] Error 1
  15. mingw32-make[1]: Leaving directory `W:/Data/qt4/einstieg/widget'
  16. mingw32-make: *** [release] Error 2
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Thank you