qt3 to qt4

This article mainly introduces the installation of Linux system Ubuntu12.04 (64bit) under Qt4.8.5, which also involves the installation of Fedora9 under QT4. 1, download software : Go to Qt's official website download Qt4.8.5 and QT Creator software , download the specific software as follows: Qt4.8.5 Software: qt-everywhere-opensource-src-4.8.5.tar.gz Qt Creator Software: qt-creator-linux-x86_64-opensource-2.5.2.bin 2, decompression

QT4 upgrade to QT5 changes: PC part: "Change Qtdir variable"Locate the. user file in the engineering root directory, such as InnoTabPlugin.vcxproj.userModify point to your QT5 root directory:Or find this file Qt4vspropertysheet.props, in which to modify:"New Qtwidgets module"As opposed to QT4, one of QT5 's major infrastructure modifications is to split the widget from the Qtgui module,New Qtwidgets modul

use of Qpainter in QT4 and drawing of common shapes such as rectangles and circles Routines: Drawing of rectangles in//qt4 #include #include #include Class Mymainwindow:public qwidget { Public: mymainwindow (Qwidget *parent = 0); private: void paintevent (

This series of blog in the first article said how to install QT4 and OpenCV, the second article said how to build a QT4 project, and how to configure OpenCV in QT4 project, this article mainly q4t some of the use of skills, while showing his powerful features. Qt4 use tips and function displayFirst to show a pict

Install Qt4 in Ubuntu through the New Software Package Manager (or command line apt. 1. The required package libqt4-debuglibqt4-guilibqt4-qt3supportlibqt4-sqlqt4-designerqt4-dev-toolsqt4-docqt4-qtconfig is recommended to remove older versions installed before installation 2. Install c ++ compiler build-essential3.ctag Install Qt4 in Ubuntu through the New Software Package Manager (or command line apt. 1.

: #include Qprinter> #include Qprintdialog> toascii () and Fromascii () have been deprecatedReplace Fromascii () Toascii () For FromLatin1 () ToLatin1 () For example, given the QT4 code qbytearry Configfileti = tmp_config. Toascii (); Into qbytearry Configfileti = tmp_config. ToLatin1 (); Qcoreapplication::unicodeutf8 has been deprecatedThis enumeration type is used to d

Use of qpainter in qt4 and painting of common figures such as Rectangles and circles Routine: // method of the rectangle in qt4 #include #include #include class MyMainWindow:public QWidget { public: MyMainWindow(QWidget *parent = 0); private: void paintEvent(QPaintEvent *); Q

Integrate qt4 with vs2005 After installing the qt4 development environment, I have never carefully studied it. I have read the official demo, but as a newbie, it is better to do it step by step! So hello World! Create a QT application project in vs2005 named "qt_test1" This project has a main. cpp file, our main file. # Include "qt_test1.h" // This can also be removed# Include # Include Int main (INT

Hardware environment: one set of tiny6410 Development Board and DS18B20 temperature acquisition Chip Software environment: Linux 2.6.38, qt4 Runtime Library Driver: 6410_ds18b20 Device File Name:/dev/DS18B20 Master Program: ts9000 Program running instructions: automatically runs after the Development Board is powered on. The running interface is as follows: 1. Click the relevant button on the main interface. 650) This. width = 650; "src =" http:/

Qt4 thread sleep About the sleep function, let's take a look at its role: the sleep function is used to sleep the thread that calls the sleep function, and the thread voluntarily gives up the time slice. After the specified interval, start the thread and continue executing the code. The sleep function does not act as a scheduled function. Its main function is latency. Sleep (0) may be displayed in some multithreading; its main purpose is to allow time

Label:One: QT network development Qnetworkaccessmanager (http://m.blog.csdn.net/blog/u010002704/41355917) An application, a qnetworkaccessmanager is enough. Every reply qnetworkreply need to delete, otherwise there will be a memory leak, according to the QT Help document, in the slot after receiving data to use Deletelater (), to prevent memory leaks. Two: Qt4 uses Qudpsocket to send datagrams datagrams UDP service user-bound broadcast [wine-drinkin

Recently in writing qglviewer, found a problem, this is not happening on the ubuntu14.04 problem,realloc Invalid pointerAfter a half-day of data Fan County is qt4 and qt5 conflict between, resulting qglviewer can not link to the correct QT version, also someone through uninstall QT5 solveBut it's not an effective solution.Finally put my solution:Add "/usr/lib/x86_64-linux-gnu/libqglviewer-qt4.so.2.6.3 \" to

(textChanged (ConstQString )), This, SLOT (Enablefindbutton (ConstQString ))); Connect (Findbutton, SIGNAL (clicked ()), This, SLOT (findclicked ())); Connect (CloseButton, SIGNAL (clicked ()), This, SLOT (Close ())); Qhboxlayout* Topleftlayout =Newqhboxlayout; Topleftlayout-addwidget (label); Topleftlayout-AddWidget (LineEdit); Qvboxlayout* Leftlayout =Newqvboxlayout; Leftlayout-addlayout (topleftlayout); Leftlayout-AddWidget (Casecheckbox); Leftlayout-AddWidget (Backwardcheckbox);

Qt4 is connected to the mysql running platform: win7 Compiler: vc IDE: vs2010 MYSQL: 5.5. If you forget it, you can leave it for others' reference. The dll and lib corresponding to www.2cto.com mysql are qsqlmysqld4.dll and qsqlmysqld4.lib. This is compiled. 1) first go to the cd % QTDIR % \ src \ plugins \ sqldrivers \ mysql directory, 2) run the command qmake-o Makefile "INCLUDEPATH + = C: \ MySQL \ include "" LIBS + = C: \ MySQL \ lib \ opt \ libmy

built-in widgets have been appropriately implemented. 5. Setting the scaling factorThe scaling factor supports the relative growth of the subwindow components, for example, allocating any excess free space of 2/3 to the A window part, and allocating 1/3 of the space to the B-window part, which will keep the ratio at 2:1. 6. Set the "spacing" between the Windows parts that are managed by the layout and the "blank " around the entire layout By default,QT uses industry-standard values that are c

. Correction 4: Lesson 5: To enter 3D, needless to say, change all the previous changes. Correction 5: Lesson 6: texture ing first, change the previous correction. Then an error is prompted during the build: Qimage dummy (128,128, 32)The third parameter is incorrect. After qt4, the third parameter isQimage: FormatIn the format of Enum, the value ranges from 0 to 18, where 32 should be changed:Qimage: format_rgb32. (For more information, see the QT doc

Qt4: Use eclipse to develop QT applications Let's take a look at the overall image. Eclipse is a great ide. It is especially difficult to get started with netbeans, especially in Java development. it not only serves as an integrated development environment for Java, but also supports integrated development of C/C ++. qiququ also provides a dedicated integrated tool for its development of QT. the following describes how to use this tool. Compared with

Chinese garbled characters appear during code writing in Qt4. Find a lot on the internet can not, and finally see here http://blog.chinaunix.net/uid-20382483-id-3030806.html Only the methods in it are available !!! I tried it myself. It is feasible !!! My code is as follows: 1 # include 2 # include 3 # include 4 # include 5 # include 6 # include 7 # include 89 int main (int argc, char * argv [])10 {11 QApplication app (argc, argv );1213 QTextCodec: se

Proficient in qt4 Programming2nd, China-Pub computer New Book recommendation Recommendation language: Best-selling versionBuild on the engineering development experience of many large projects Basic InformationAuthor: Cai Zhiming Lu Chuanfu Li lixiaPress: Electronic Industry PressISBN: 9787121125256IntroductionThis book details the basic knowledge of QT and the application of GUI programming. The example is informative and the content is comprehensiv

() uses the inspector set in the constructor to determine the validity of the content in the row editor*/ -Okbutton->setenabled (lineedit->hasacceptableinput ()); -}3. Gotocelldialog.h1 /**/2 #ifndef Gotocelldialog_h3 #defineGotocelldialog_h4 5#include 6 7#include"ui_gotocelldialog.h"8 9 classGotocelldialog: PublicQdialog, PublicUi::gotocelldialogTen { One Q_object A - Public: -Gotocelldialog (Qwidget *parent =0); the - PrivateSlots: - voidon_lineedit_textchanged (); - }; + - #e