无效使用不完整的类型/前瞻性声明

Question

我一直在寻找有关此问题的信息..但是我发现的任何解决方案都没有帮助我，我真的希望您能提供帮助

• maintabholder.h：

   #ifndef MAINTABHOLDER_H #define MAINTABHOLDER_H #include <QMainWindow> namespace Ui { class MainTabHolder; } class MainTabHolder : public QMainWindow { Q_OBJECT public: explicit MainTabHolder(QWidget *parent = 0); ~MainTabHolder(); private: Ui::MainTabHolder *ui; }; #endif // MAINTABHOLDER_H 

• maintabholder.cpp：

   #include "maintabholder.h" #include "ui_maintabholder.h" MainTabHolder::MainTabHolder(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainTabHolder) { ui->setupUi(this); } MainTabHolder::~MainTabHolder() { delete ui; } 

• main.cpp：

   #include "maintabholder.h" #include <QApplication> int main(int argc, char *argv[]) { QApplication a(argc, argv); MainTabHolder w; w.show(); return a.exec(); } 

• ui_maintabholder.h #ifndef UI_MAINTABHOLDER_H＃定义UI_MAINTABHOLDER_H

   #include <QtCore/QVariant> #include <QtWebKitWidgets/QWebView> #include <QtWidgets/QAction> #include <QtWidgets/QApplication> #include <QtWidgets/QButtonGroup> #include <QtWidgets/QHBoxLayout> #include <QtWidgets/QHeaderView> #include <QtWidgets/QPushButton> #include <QtWidgets/QSpacerItem> #include <QtWidgets/QTabWidget> #include <QtWidgets/QVBoxLayout> #include <QtWidgets/QWidget> QT_BEGIN_NAMESPACE class Ui_Form { public: QHBoxLayout *horizontalLayout; QTabWidget *tabWidget; QWidget *comicViewer; QWidget *comicSearcher; QVBoxLayout *verticalLayout; QHBoxLayout *horizontalLayout_2; QPushButton *pushButton; QSpacerItem *horizontalSpacer; QPushButton *pushButton_2; QWebView *webView; void setupUi(QWidget *Form) { if (Form->objectName().isEmpty()) Form->setObjectName(QStringLiteral("Form")); Form->resize(531, 308); horizontalLayout = new QHBoxLayout(Form); horizontalLayout->setObjectName(QStringLiteral("horizontalLayout")); tabWidget = new QTabWidget(Form); tabWidget->setObjectName(QStringLiteral("tabWidget")); comicViewer = new QWidget(); comicViewer->setObjectName(QStringLiteral("comicViewer")); comicViewer->setCursor(QCursor(Qt::ArrowCursor)); tabWidget->addTab(comicViewer, QString()); comicSearcher = new QWidget(); comicSearcher->setObjectName(QStringLiteral("comicSearcher")); verticalLayout = new QVBoxLayout(comicSearcher); verticalLayout->setObjectName(QStringLiteral("verticalLayout")); horizontalLayout_2 = new QHBoxLayout(); horizontalLayout_2->setObjectName(QStringLiteral("horizontalLayout_2")); pushButton = new QPushButton(comicSearcher); pushButton->setObjectName(QStringLiteral("pushButton")); horizontalLayout_2->addWidget(pushButton); horizontalSpacer = new QSpacerItem(40, 20, QSizePolicy::Expanding, QSizePolicy::Minimum); horizontalLayout_2->addItem(horizontalSpacer); pushButton_2 = new QPushButton(comicSearcher); pushButton_2->setObjectName(QStringLiteral("pushButton_2")); pushButton_2->setEnabled(false); horizontalLayout_2->addWidget(pushButton_2); verticalLayout->addLayout(horizontalLayout_2); webView = new QWebView(comicSearcher); webView->setObjectName(QStringLiteral("webView")); webView->setUrl(QUrl(QStringLiteral("about:blank"))); verticalLayout->addWidget(webView); tabWidget->addTab(comicSearcher, QString()); horizontalLayout->addWidget(tabWidget); retranslateUi(Form); tabWidget->setCurrentIndex(1); QMetaObject::connectSlotsByName(Form); } // setupUi void retranslateUi(QWidget *Form) { Form->setWindowTitle(QApplication::translate("Form", "Form", 0)); tabWidget->setTabText(tabWidget->indexOf(comicViewer), QApplication::translate("Form", "Comic Viewer", 0)); pushButton->setText(QApplication::translate("Form", "Go to SubManga", 0)); pushButton_2->setText(QApplication::translate("Form", "Download Comic", 0)); tabWidget->setTabText(tabWidget->indexOf(comicSearcher), QApplication::translate("Form", "Search For Comics", 0)); } // retranslateUi }; namespace Ui { class Form: public Ui_Form {}; } // namespace Ui QT_END_NAMESPACE #endif // UI_MAINTABHOLDER_H 

编译器错误是：

    [...]\maintabholder.cpp: In constructor 'MainTabHolder::MainTabHolder(QWidget*)':
    [...]\maintabholder.cpp:6:16: error: invalid use of incomplete type 'class Ui::MainTabHolder'
    In file included from [...]\maintabholder.cpp:1:0:
    [...]\maintabholder.h:7:7: error: forward declaration of 'class Ui::MainTabHolder'
    [...]\maintabholder.cpp:8:7: error: invalid use of incomplete type 'class Ui::MainTabHolder'
    In file included from [...]\maintabholder.cpp:1:0:
    [...]\maintabholder.h:7:7: error: forward declaration of 'class Ui::MainTabHolder'
    [...]\maintabholder.cpp: In destructor 'virtual MainTabHolder::~MainTabHolder()':
    [...]\maintabholder.cpp:13:12: warning: possible problem detected in invocation of delete operator: [enabled by default]
    [...]\maintabholder.cpp:13:12: warning: invalid use of incomplete type 'class Ui::MainTabHolder' [enabled by default]
    In file included from [...]\maintabholder.cpp:1:0:
    [...]\maintabholder.h:7:7: warning: forward declaration of 'class Ui::MainTabHolder' [enabled by default]
    [...]\maintabholder.cpp:13:12: note: neither the destructor nor the class-specific operator delete will be called, even if they are declared when the class is defined

你能帮忙吗？ 我会很感激...

Answer 1

您正在使用uic从Qt生成的文件； 您应该通过例如检查构建输出和文件本身来验证此工具是否成功生成了文件。 另外，检查它是否在*.pro文件中（即， maintabholder.h被标记为由uic处理）。

我个人建议对ui使用多重继承方法 ：

// in maintabholder.h
// ...
#include "ui_maintabholder.h"

class MainTabHolder : public QMainWindow, public Ui::MainTabHolder
{
    // ...
};

使用更简单，如果ui_*.h文件有问题，则错误更明显。

您应该发布ui_maintabholder.h 。

Answer 2

您已在.cpp文件中包含ui定义头，并定义了一个私有成员“ Ui :: MainTabHolder * ui;”。 在.h文件中，因此您需要在.h文件（maintabholder.h :)中添加前向声明：

class Ui_MainTabHolder;

这里Ui_MainTabHolder是您的Ui类名称，请检查您自己的项目是否正确。