Qt-Qt之Invokemethhod使用方法与详解

资料：

https://www.jianshu.com/p/c77e28a81708      Qt invokeMethod 异步调用

https://download.csdn.net/download/zhujianqiangqq/92466941     csdn下载代码包

 

注意项：

Qt::DirectConnection，则会立即调用该成员。(同步调用)

Qt::QueuedConnection，则会发送一个QEvent，并在应用程序进入主事件循环后立即调用该成员。(异步调用)

Qt::BlockingQueuedConnection，则将以与Qt :: QueuedConnection相同的方式调用该方法，除了当前线程将阻塞直到事件被传递。使用此连接类型在同一线程中的对象之间进行通信将导致死锁。(异步调用)

Qt::AutoConnection，则如果obj与调用者位于同一个线程中，则会同步调用该成员; 否则它将异步调用该成员。

注：

1.必须引入Q_OBJECT机制。

2.每个对外的方法必须写Q_INVOKABLE进行定义。

3.必须要使用Q_RETURN_ARG()宏来封装函数返回值、Q_ARG()宏来封装函数参数。

 

代码实例：

.pro

 1 QT       += core gui
 2 
 3 greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
 4 
 5 CONFIG += c++11
 6 
 7 # The following define makes your compiler emit warnings if you use
 8 # any Qt feature that has been marked deprecated (the exact warnings
 9 # depend on your compiler). Please consult the documentation of the
10 # deprecated API in order to know how to port your code away from it.
11 DEFINES += QT_DEPRECATED_WARNINGS
12 
13 # You can also make your code fail to compile if it uses deprecated APIs.
14 # In order to do so, uncomment the following line.
15 # You can also select to disable deprecated APIs only up to a certain version of Qt.
16 #DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0
17 
18 SOURCES += \
19     TestInvokemethhodWidget.cpp \
20     main.cpp \
21     mainwindow.cpp \
22     ttestwidget.cpp
23 
24 HEADERS += \
25     TestInvokemethhodWidget.h \
26     mainwindow.h \
27     ttestwidget.h
28 
29 FORMS += \
30     mainwindow.ui
31 
32 # Default rules for deployment.
33 qnx: target.path = /tmp/$${TARGET}/bin
34 else: unix:!android: target.path = /opt/$${TARGET}/bin
35 !isEmpty(target.path): INSTALLS += target
View Code

main.cpp

 1 #include "mainwindow.h"
 2 
 3 #include <QApplication>
 4 
 5 int main(int argc, char *argv[])
 6 {
 7     QApplication a(argc, argv);
 8     MainWindow w;
 9     w.show();
10     return a.exec();
11 }
View Code

mainwindow.h

 1 #ifndef MAINWINDOW_H
 2 #define MAINWINDOW_H
 3 
 4 #include <QMainWindow>
 5 #include <QDebug>
 6 
 7 #include "TestInvokemethhodWidget.h"
 8 #include "ttestwidget.h"
 9 
10 QT_BEGIN_NAMESPACE
11 namespace Ui { class MainWindow; }
12 QT_END_NAMESPACE
13 
14 class MainWindow : public QMainWindow
15 {
16     Q_OBJECT
17 
18 public:
19     MainWindow(QWidget *parent = nullptr);
20     ~MainWindow();
21 
22 private slots:
23     void on_pushButton_clicked();
24 
25     void on_pushButton_2_clicked();
26 
27     void on_pushButton_3_clicked();
28 
29     void on_pushButton_4_clicked();
30     void on_ShowText(QString value);
31     void on_pushButton_5_clicked();
32 
33     void on_pushButton_6_clicked();
34 
35     void on_pushButton_7_clicked();
36 
37 private:
38     Ui::MainWindow *ui;
39     TTestInvokemethhodWidget *mTestInvokemethhodWidget = nullptr;
40     TTestWidget *mTestWidget = nullptr;
41     QLabel *mLabel = nullptr;
42 };
43 #endif // MAINWINDOW_H
View Code

mainwindow.cpp

 1 #include "mainwindow.h"
 2 #include "ui_mainwindow.h"
 3 
 4 MainWindow::MainWindow(QWidget *parent)
 5     : QMainWindow(parent)
 6     , ui(new Ui::MainWindow)
 7 {
 8     ui->setupUi(this);
 9     this->setWindowTitle(QStringLiteral("Qt之Invokemethhod使用方法与详解"));
10 
11     mLabel = new QLabel(QStringLiteral("主界面"), this);
12     mLabel->move(10, 300);
13 
14     mTestInvokemethhodWidget = new TTestInvokemethhodWidget(this);
15     mTestInvokemethhodWidget->move(0, 0);
16     connect(mTestInvokemethhodWidget, &TTestInvokemethhodWidget::do_Text, this, &MainWindow::on_ShowText);
17 
18     mTestWidget = new TTestWidget(this);
19     mTestWidget->move(200, 0);
20     connect(mTestWidget, &TTestWidget::do_Text, this, &MainWindow::on_ShowText);
21 }
22 
23 MainWindow::~MainWindow()
24 {
25     delete ui;
26 }
27 
28 
29 void MainWindow::on_pushButton_clicked()
30 {
31     if(mTestInvokemethhodWidget) mTestInvokemethhodWidget->TestInvokemethhod();
32 }
33 
34 void MainWindow::on_pushButton_2_clicked()
35 {
36 
37 }
38 
39 void MainWindow::on_pushButton_3_clicked()
40 {
41     bool bReturn = false;
42     QString s = "bReturn:%1";
43     if(mTestInvokemethhodWidget) bReturn = mTestInvokemethhodWidget->TestInvokemethhodReturn();
44     ui->textEdit->append(s.arg(bReturn));
45 }
46 
47 void MainWindow::on_pushButton_4_clicked()
48 {
49     QLabel *oLabel = nullptr;
50     QString s = "oLabel:%1";
51     if(mTestInvokemethhodWidget) oLabel = mTestInvokemethhodWidget->TestInvokemethhodObject();
52     if(oLabel) ui->textEdit->append(s.arg(oLabel->text()));
53 }
54 
55 void MainWindow::on_ShowText(QString value)
56 {
57     ui->textEdit->append(value);
58 }
59 
60 void MainWindow::on_pushButton_5_clicked()
61 {
62     if(mTestInvokemethhodWidget) mTestInvokemethhodWidget->setInvokemethhod(9);
63 }
64 
65 void MainWindow::on_pushButton_6_clicked()
66 {
67     if(mTestInvokemethhodWidget) mTestInvokemethhodWidget->setInvokemethhodObject(mLabel);
68 }
69 
70 void MainWindow::on_pushButton_7_clicked()
71 {
72     int n = 0;
73     QString s = "AndOut:%1";
74     if(mTestInvokemethhodWidget) n = mTestInvokemethhodWidget->setInvokemethhodInAndOut(6);
75     ui->textEdit->append(s.arg(n));
76 }
View Code

TestInvokemethhodWidget.h

 1 #ifndef TTESTINVOKEMETHHOD_H
 2 #define TTESTINVOKEMETHHOD_H
 3 
 4 #include <QObject>
 5 #include <QWidget>
 6 #include <QVBoxLayout>
 7 #include <QPushButton>
 8 #include <QMessageBox>
 9 #include <QLabel>
10 
11 class TTestInvokemethhodWidget : public QWidget
12 {
13     Q_OBJECT // 必须写Q_OBJECT
14 public:
15     TTestInvokemethhodWidget(QWidget* parent = nullptr);
16     Q_INVOKABLE void TestInvokemethhod();// 必须写Q_INVOKABLE
17     Q_INVOKABLE bool TestInvokemethhodReturn();
18     Q_INVOKABLE QLabel* TestInvokemethhodObject();
19 
20     Q_INVOKABLE void setInvokemethhod(int value);
21     Q_INVOKABLE void setInvokemethhodObject(QLabel *label);
22     Q_INVOKABLE int setInvokemethhodInAndOut(int value);
23     QLabel *mL = nullptr;
24 private slots:
25 signals:
26     void do_Text(QString value);
27 };
28 
29 #endif // TTESTINVOKEMETHHOD_H
View Code

TestInvokemethhodWidget.cpp

 1 #include "TestInvokemethhodWidget.h"
 2 
 3 TTestInvokemethhodWidget::TTestInvokemethhodWidget(QWidget *parent)
 4     :QWidget(parent)
 5 {
 6     this->setObjectName("TTestInvokemethhodWidget");
 7     this->resize(100, 280);
 8 
 9     mL = new QLabel(QStringLiteral("子界面-被调用界面"), this);
10 }
11 
12 void TTestInvokemethhodWidget::TestInvokemethhod()
13 {
14     QMessageBox::information(nullptr, QStringLiteral("提示"), QStringLiteral("TestInvokemethhod 调用"));
15 }
16 
17 bool TTestInvokemethhodWidget::TestInvokemethhodReturn()
18 {
19     QMessageBox::information(nullptr, QStringLiteral("提示"), QStringLiteral("TestInvokemethhodReturn 调用"));
20     return true;
21 }
22 
23 QLabel *TTestInvokemethhodWidget::TestInvokemethhodObject()
24 {
25     return mL;
26 }
27 
28 void TTestInvokemethhodWidget::setInvokemethhod(int value)
29 {
30     QString s = "TTestInvokemethhodWidget::setInvokemethhod:%1";
31     emit do_Text(s.arg(value));
32 }
33 
34 void TTestInvokemethhodWidget::setInvokemethhodObject(QLabel *label)
35 {
36     if(nullptr != label)
37     {
38         emit do_Text(label->text());
39     }
40 }
41 
42 int TTestInvokemethhodWidget::setInvokemethhodInAndOut(int value)
43 {
44     int n = 0;
45     n = 15 + value;
46     return n;
47 }
View Code

ttestwidget.h

 1 #ifndef TTESTWIDGET_H
 2 #define TTESTWIDGET_H
 3 
 4 #include <QObject>
 5 #include <QWidget>
 6 #include <QVBoxLayout>
 7 #include <QPushButton>
 8 #include <QMessageBox>
 9 #include <QLabel>
10 #include <QDebug>
11 
12 class TTestWidget : public QWidget
13 {
14     Q_OBJECT
15 public:
16     TTestWidget(QWidget* parent = nullptr);
17 private:
18     QLabel *mLabel = nullptr;
19 
20     QPushButton *mB1 = nullptr;
21     QPushButton *mB2 = nullptr;
22     QPushButton *mB3 = nullptr;
23 
24     QPushButton *mB4 = nullptr;
25     QPushButton *mB5 = nullptr;
26     QPushButton *mB6 = nullptr;
27 private slots:
28     void on_B1();
29     void on_B2();
30     void on_B3();
31     void on_B4();
32     void on_B5();
33     void on_B6();
34 signals:
35     void do_Text(QString value);
36 };
37 
38 #endif // TTESTWIDGET_H
View Code

ttestwidget.cpp

  1 #include "ttestwidget.h"
  2 
  3 TTestWidget::TTestWidget(QWidget *parent)
  4     :QWidget(parent)
  5 {
  6     this->resize(400, 300);
  7 
  8     mLabel = new QLabel(QStringLiteral("子界面-调用界面"), this);
  9 
 10     mB1 = new QPushButton(QStringLiteral("运行时调用TestInvokemethhod"), this);
 11     mB1->move(20, 20);
 12     mB1->resize(250, 25);
 13     connect(mB1, &QPushButton::clicked, this, &TTestWidget::on_B1);
 14 
 15     mB2 = new QPushButton(QStringLiteral("运行时调用TestInvokemethhodReturn"), this);
 16     mB2->move(mB1->x(), mB1->y() + mB1->height() + 10);
 17     mB2->resize(250, 25);
 18     connect(mB2, &QPushButton::clicked, this, &TTestWidget::on_B2);
 19 
 20     mB3 = new QPushButton(QStringLiteral("运行时调用TestInvokemethhodObject"), this);
 21     mB3->move(mB2->x(), mB2->y() + mB2->height() + 10);
 22     mB3->resize(250, 25);
 23     connect(mB3, &QPushButton::clicked, this, &TTestWidget::on_B3);
 24 
 25     mB4 = new QPushButton(QStringLiteral("运行时调用setInvokemethhod"), this);
 26     mB4->move(mB3->x(), mB3->y() + mB3->height() + 30);
 27     mB4->resize(250, 25);
 28     connect(mB4, &QPushButton::clicked, this, &TTestWidget::on_B4);
 29 
 30     mB5 = new QPushButton(QStringLiteral("运行时调用setInvokemethhodObject"), this);
 31     mB5->move(mB4->x(), mB4->y() + mB4->height() + 10);
 32     mB5->resize(250, 25);
 33     connect(mB5, &QPushButton::clicked, this, &TTestWidget::on_B5);
 34 
 35     mB6 = new QPushButton(QStringLiteral("运行时调用setInvokemethhodInAndOut"), this);
 36     mB6->move(mB5->x(), mB5->y() + mB5->height() + 10);
 37     mB6->resize(250, 25);
 38     connect(mB6, &QPushButton::clicked, this, &TTestWidget::on_B6);
 39 }
 40 
 41 void TTestWidget::on_B1()
 42 {
 43     QWidget *oTest = parent()->findChild<QWidget*>("TTestInvokemethhodWidget");
 44     if (nullptr != oTest)
 45     {
 46         QMetaObject::invokeMethod(oTest, "TestInvokemethhod"); // Qt::DirectConnection
 47     }
 48 }
 49 
 50 void TTestWidget::on_B2()
 51 {
 52     bool bReturn = false;
 53     QString s = "TTestWidget::bReturn:%1";
 54     QWidget *oTest = parent()->findChild<QWidget*>("TTestInvokemethhodWidget");
 55     if (nullptr != oTest)
 56     {
 57         QMetaObject::invokeMethod(oTest, "TestInvokemethhodReturn", Qt::DirectConnection, Q_RETURN_ARG(bool, bReturn));
 58     }
 59     do_Text(s.arg(bReturn));
 60 }
 61 
 62 void TTestWidget::on_B3()
 63 {
 64     QLabel* oLabel;
 65     QString s = "TTestWidget::oLabel:%1";
 66     QWidget *oTest = parent()->findChild<QWidget*>("TTestInvokemethhodWidget");
 67     if (nullptr != oTest)
 68     {
 69         QMetaObject::invokeMethod(oTest, "TestInvokemethhodObject", Qt::DirectConnection, Q_RETURN_ARG(QLabel*, oLabel));
 70     }
 71     emit do_Text(s.arg(oLabel->text()));
 72 }
 73 
 74 void TTestWidget::on_B4()
 75 {
 76     QWidget *oTest = parent()->findChild<QWidget*>("TTestInvokemethhodWidget");
 77     if (nullptr != oTest)
 78     {
 79         QMetaObject::invokeMethod(oTest, "setInvokemethhod", Qt::DirectConnection, Q_ARG(int, 8));
 80     }
 81 }
 82 
 83 void TTestWidget::on_B5()
 84 {
 85     QWidget *oTest = parent()->findChild<QWidget*>("TTestInvokemethhodWidget");
 86     if (nullptr != oTest)
 87     {
 88         QMetaObject::invokeMethod(oTest, "setInvokemethhodObject", Qt::DirectConnection, Q_ARG(QLabel*, mLabel));
 89     }
 90 }
 91 
 92 void TTestWidget::on_B6()
 93 {
 94     int n = 0;
 95     QString s = "TTestWidget::AndOut:%1";
 96     QWidget *oTest = parent()->findChild<QWidget*>("TTestInvokemethhodWidget");
 97     if (nullptr != oTest)
 98     {
 99         QMetaObject::invokeMethod(oTest, "setInvokemethhodInAndOut", Qt::DirectConnection, Q_RETURN_ARG(int, n), Q_ARG(int, 3));
100     }
101     emit do_Text(s.arg(n));
102 }
View Code

 

posted on 2025-12-16 16:26  疯狂delphi  阅读(2)  评论(0)    收藏  举报

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