Qt-透明窗体之半透明

 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     main.cpp 20     windowDesktop.cpp
21 
22 HEADERS += 23     windowDesktop.h
24 
25 FORMS += 26     mainwindow.ui
27 
28 LIBS += -lUser32
29 
30 # Default rules for deployment.
31 qnx: target.path = /tmp/$${TARGET}/bin
32 else: unix:!android: target.path = /opt/$${TARGET}/bin
33 !isEmpty(target.path): INSTALLS += target
34 
35 RESOURCES += 36     resource.qrc

 1 #include  2 #include  3 #include  4 #include "windowDesktop.h"
 5 
 6 int main(int argc, char *argv[])
 7 {
 8     QApplication a(argc, argv);
 9 
10     Dialog w;
11     w.setWindowFlag(Qt::FramelessWindowHint);
12     w.setFixedSize(QSize(800, 400));
13     w.show();
14     return  a.exec();
15 }

 1 #ifndef WINDOWDESKTOP_H
 2 #define WINDOWDESKTOP_H
 3 
 4 #include "QObject"
 5 #include "QDialog"
 6 #include "QLineEdit"
 7 #include "QPainter"
 8 #include "QWidget"
 9 #include "QBitmap"
10 #include "QPushButton"
11 
12 class  Dialog :  public  QWidget
13 {
14  Q_OBJECT
15 public :
16  Dialog(QWidget *parent = 0);
17  ~Dialog();
18 
19   virtual void paintEvent(QPaintEvent *event);
20 };
21 
22 
23 #endif // WINDOWDESKTOP_H

 1 #include "windowDesktop.h"
 2 
 3 Dialog::Dialog(QWidget *parent)
 4     : QWidget(parent)
 5 {    
 6     // 创建个LineEdit用来测试焦点
 7     QLineEdit *le = new QLineEdit(this);
 8     QPushButton *oButton = new QPushButton(this);
 9     oButton->setText("test");
10     oButton->setGeometry(30, 30, 100, 30);
11 
12     this->setAttribute(Qt::WA_TranslucentBackground, true);
13 }
14 
15 Dialog::~Dialog()
16 {
17 }
18 
19 void Dialog::paintEvent(QPaintEvent *event)
20 {
21     QPainter p(this);
22     p.fillRect(rect(), QColor(0, 0xff, 0, 33));
23     return;
24 }