learn qt c

Tags: qt gdb makefile parametersIn Qt, to add the relevant compilation parameters in the makefile can be achieved by modifying them in the Xx.pro file:Implemented in Xx.pro by using the Qmake_cxxflags setting (for example, to add gdb debug parameters)Qmake_cxxflags + =-g (may appear in the Xx.pro file is black, others appear to have purple)After recompiling, you can use the GDB command to debug.This article

Original address: http://www.kdab.com/qt-android-episode-5/We already know how to build a QT on Android development environment, how to use Qt on Android, what deployment strategies are available and how to sign the app, and it's time to move on. In this article, we talk about JNI. (BogDan, I waited for you for a long time, when I wrote "

Go Comparison between KDE/QT and GNOME/GTKHttp://www.cnblogs.com/itech/archive/2009/08/18/1548964.htmlWhile there is a commercial rivalry, the developer relationship between GNOME and KDE is not getting any worse, but they are aware of the importance of supporting each other--if KDE and GNOME are unable to share the application, it is not only a huge waste of resources, but will lead to a fundamental division of Linux. Since 2003, after more than two

database for which you want to import tables. After that, insert data in the same way, write the insert Data command in a net text file, and then execute the import command. After completing the preceding steps, you can perform a simple database connection test to check whether the database can be connected. # Include Click Run to see: You can view the queried data. So far, all the simple compilation and testing work has been completed. Dear friends, please try your

can be seen from the code, only bytestoread big words, only recalculate. If the readbuffermaxsize is set too large, it will not be recalculated. 4. Call the read function to try to read the Bytestoread length data. Returns the actual read data length readbytes. Through the debugging can see Readbytes and bytestoread difference is not many. The bytesavailable () function returns the buffer length. If Readbuffermaxsize is not set, the function return value depends primarily on the IOCTL system ca

(suffixed with a), because I want to compile QT statically. I found that my/home folder is only over 50 MB! I accidentally compiled example and demo. In particular, example has 4G! Damn it, I decisively deleted the example folder and demo folder, including the bin, include, and Lib folders, and some unused folders add up to a total of G. Okay. I want to try to use the static library as a version so that qtcreator can recognize it. However, you are no

The Book of qt4 (1.5 QT overview) The Book of qt4 Translation Qt programming Art --------------------------------------------------------------------------------- Original Name: The Book of QT 4: The art of building QT applications The Book of QT 4 Chinese version:

time, you can also share DLL files, so you can use the default method.To learn more about QT release and static compilation methods, you can view the deploying QT applications keyword in the QT Creator Help index, and the Windows platform Publisher keyword is deploying an Application on Windows.Reference header file,

Embedded: // With mouse and touch. /Configure-Prefix/root/desktop/mini2440/qt4embed_install-fast-no-largefile-no-qt3support-no-xmlpatterns-no-WebKit-no-SVG-Embedded ARM-little-Endian- no-qvfb-no-mouse-qvfb-confirm-license-silent-xplatform qws/Linux-arm-G ++// Added tslib support:. /Configure-Prefix/usr/local/qt4_tslib_install-fast-no-largefile-no-qt3support-no-MMX-no-3dnow-no-xmlpatterns-no-WebKit-no-SVG-nomake demo- nomake docs-no-OpenSSL-Embedded ARM-little-Endian-no-qvfb-no-mouse-qvfb-Dept

To add a right-click menu bar in a form, for example, add a menu bar in qtreewidget, The slot function customcontextmenurequested can be used.(QpointPos). If it is in QT creator, right-click qtreewidget --> go to slot -- -->Select customcontextmenurequested(QpointPos). Then, in the newly created customcontextmenurequested(QpointPos) Function to implement the specific menu bar. In order to determine the right-click position, that is,

Write static dynamic graph with QT, static dynamic histogram with qtRecently, several projects have been successively implemented, requiring the use of curves and bar charts to dynamically display data. Therefore, we have specially studied the qcustomplot open-source Drawing Library! As kimit in the garden said, although qcustomplot is a header file and implementation file, it is easy to use, but the code is much more messy than QWT, and the readabili

fourth argument buttons, the button that declares the dialog box, and the default is to place an OK button. This parameter can be used or the operation, for example we want to have a Yes and a No button, you can use Qmessagebox::yes | Qmessagebox::no, All button types can be found in the Standarbutton enumeration of the Qmessagebox declaration, the fifth parameter DefaultButton is the default selected button, and the default value is Nobutton, That is, which button is not selected. So many para

How to get the screen size in Qt. First call a static method in the Qapplication class, as follows: Qdesktopwidget *qapplication::d esktop () The Qapplication class is used to manage the control flow and primary settings for GUI applications, with the following derived relationships: QApplication:QGuiApplication:QCoreApplication:QObject In the main program, it must be qapplication rather than qguiapplication or qcoreapplication, otherwise there will

the dictionary I designed not only allows you to look up words online, but also has a great feature of a rich local dictionary library : I've added eight types of dictionaries by default, as shown here:because I am a communications professional, so joined the Huawei Communications Dictionary, Electronic Engineering dictionary, and because I love programming, but also added the C language basic function dictionary. Here's how to design a local dictionary:selection of dictionary typesOf Course the

palette = infotextedit-> palette (); // obtain the color palette object for text editing. // qcolor color = qcolordialog: getcolor (qpalette: Base, this ); // The initial color value of the color dialog box is the background color qcolor color = qcolordialog: getcolor (palette. color (qpalette: base), this); // if you click Cancel in the color dialog box, the resulting color is invalid if (color. isvalid () {// qpalette: base is usually used for background color palette. setcolor (qpalette: Bas

Recently used QT5 to do a project interface, in the translation into executable exe, run the file, prompt:This application failed-to-start because it could not find or load the Qt PLATFORM Plugin "Windows"In "".Reinstalling the application may fix this problem.Looked up a lot of information, tried the method, and later found that the D:\Anaconda2\Library\plugins under the platforms folder copied to the project file directory (to copy the entire folder

Qt implements system pallets and qt implements pallets Most of the software we see usually comes with a system tray, so that the software can run in the background, which is quite good. Today, I checked the demon that comes with Qt. I have a reference in the middle. After implementing this small function, I added this function to my previous project. The effect i

Gray-scale transformation of Qt image processing and qt gray-scale Changing the brightness and contrast of an image is a common image processing operation, but Qt itself does not provide the corresponding functional code. Therefore, I wrote a simple class to implement these operations. I call this class BrightnessMapper. The Code is as follows: #ifndef BRIGHTNE

I wrote a Qt display image control and a qt display image control. There is no control for displaying images in Qt. We usually use QLabel to display images. However, the QLabel image display capability is weak. For example, image scaling is not supported. So I wrote a simple class myself. My class supports three image display modes: FIXED_SIZE, CENTRED, AUTO_ZOO

Use Qt. locale to display local data, and use qt. locale to localize We know that for some applications, we can display different data formats, such as time and money, based on the language selection. In today's routine, we will show you how to use Qt. locale to display data in different formats based on different languages. import QtQuick 2.0import Ubuntu.Comp