General and Desktop

• 

  How to create the plugin of MYSQL for Qt
  • BlackStar

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  @flydragon

  Do not duplicate posting because you do not get an answer immendiately.

  [edit:koahnig see https://forum.qt.io/topic/82629/why-qsqlquery-exec-exit-failed ]

• 

  Reporting inappropriate content on the forums
  spam • • Eddy

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  Thank you for the report. I have banned the user, which got rid of the spam posting. Not a loss, as this user did not post any other content on the site. Just deleting this one posting was not possible.

  Thanks for reporting this.

• 

  Unsolved Is there have relationship between QWidget and QWindow after QWindow pop up?
  • richie18

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  @SGaist

  Use code below as application A.
  When application A is poped up, click the 'block process' button in applicaiton A. Then application B's process is also blocked.

  # -*- coding: utf-8 -*- import sys from PyQt5.QtWidgets import QWidget, QApplication, QVBoxLayout, QPushButton class MyWidget(QWidget): def __init__(self, parent=None): super(MyWidget, self).__init__(parent) self.setWindowTitle("block application") layout = QVBoxLayout(self) blockBtn = QPushButton("block process") layout.addWidget(blockBtn) blockBtn.clicked.connect(self.block) self.resize(300, 200) def block(self): import time while True: print(time.time()) if __name__ == '__main__': app = QApplication(sys.argv) widget = MyWidget() widget.show() app.exec_()
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  Unsolved how can i connection QSqlDatabase oracle with user shema?
  • Everton Fonseca

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  No one has replied

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  Unsolved Smooth scaling QPixmap
  • patrickkidd

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  Class problem
  • Nafab213

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  I read and reread but I see only one detail but when I regulate the detail. I am always in the same situation.

  That's the detail I added

  QStackedWidget *centralfencen = new QStackedWidget; stackedWidget->addWidget(new FenCene); stackedWidget->addWidget(new FenCenep);

  Precision I start in programming and I want to learn so help me a little and this mistake will be learned forever ..
  Please..

• 

  Unsolved What calls paintGL
  • BKBK

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  @kshegunov said in What calls paintGL:

  @BKBK said in What calls paintGL:

  This is Qt3 using QGLWidget.

  This is a mistake, right? You don't mean 15+ years old code, I hope.

  Unfortunately, we are using Qt3. The government Information Protection team (name has been recently updated, I might not have the latest) has changed their rules about using code that is foreign owned. They hate that. And I have been told hate open source. Never did understand that. From what I have found Qt has always been foreign owned, but the rules changed since we started with Qt so we can keep what we have but cannot introduce the new stuff.
  A Royal PIA.

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  Unsolved Dynamically fit QComboBox popup height to the (dynamically changing) count of items
  qcombobox view resize qlistview item • • AloyseTech

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  @AloyseTech Agree my solution is complicated, your resizing code looks good, should work too. Don't know about the item height, but perhaps divide view()->window()->height() with # of items?

  Just guessing here, but couldn't you do something llke:

  hidePopup(); showPopup();

  to sort of "force" the QComboBox into good behavior?

  Edit: perhaps with a qApp->processEvents() sandwiched in between them....

• 

  Unsolved Are Qt Remote Objects supported by Webassembly
  • Martin

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  @raven-worx said in Are Qt Remote Objects supported by Webassembly:

  @hgerdau said in Are Qt Remote Objects supported by Webassembly:

  Than you could connect to any host bypassing the sandbox.

  Thats not how it works, as i said its only allowed to make connections to the host domain

  You are wrong. Same origin is forced only for tcp sockets but not for websockets.
  Please google for Same-Origin-Policy (SOP) and websockets.
  And by the way I have wasm code running that shows that it works with websockets.

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  Unsolved upgrade SDK on macOs Qt version
  • AmirAbbasi

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  @SGaist
  the code was run
  thanks a lot

• 

  Unsolved update qsqlite and qtableview
  • Mogli123

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  Hi,

  @Mogli123 said in update qsqlite and qtableview:

  myModelToolChangeWarnings

  What is that class ?

  Can you explain more precisely what you mean by "at the wrong place" ?

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  Unsolved macdeployqt for a daemon process
  • vivian

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  No one has replied

• 

  [SOLVED] - QTableView - change cursor when hovering specific column
  • maximus

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  Hi and welcome to devnet,

  What version of Qt ?
  On what platform ?

• 

  QString::sprintf question
  • Eonz

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  @Morbius Both asprintf and fromWCharArray are static methods. Don't create temporary instances just to call them. Just use directly: QString::asprintf(... and QString::fromWCharArray(...

  You don't need std to use Unicode (and by Unicode I mean UTF-16, just to be clear, because there's more then one type of Unicode).
  QString is UTF-16 internally so there's no point in doing it via std::swprintf. Format string in QString::asprintf is expected to be UTF-8 so it can hold whatever UTF-16 can. If you have arguments that are UTF-16 strings then these are also supported directly via %lc and %ls.

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  Unsolved Running Qt Application from .dll
  • Theok

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  The .pro file looks correct.

  However, as suggested before, use consistent file naming. You have a widget called MainWindow, then you should have kept the original file name generated for you by Qt Creator. There's no need for any special naming because you are creating a library.

• 

  Unsolved Can I host QT based apps on DigitalOcean cloud servers.?
  • MariaWilliams

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  Hi and welcome to devnet,

  What exactly do you want to host there ?
  Is it the backend of your application ?
  The application itself ?

  On a side note, it's Qt. QT stands for Apple's QuickTime which is not what you are currently developing with.

• 

  Unsolved How should post data to API that has ContentTypeHeader:"text/plain; charset=utf-8" ?
  • zhmh

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  Hi,

  From the looks of it, you are trying to send the wrong kind of data to that end point. You should check its documentation to see what it expects.

  The fact that it replies with text has nothing to do with what is valid to send to it.

• 

  Unsolved Main Project do not update after Static Library Change
  • mahd96

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  Hi,

  IIRC; you can use PRE_TARGETDEPS for that.

• 

  Unsolved QSortFilterProxyModel not mapping properly
  qsorfilterproxy qmodelindex itemmodel • • zmurphy

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  You can check you model implementation with the QAbstractItemModelTester. See this wiki entry.

• 

  Unsolved OpenStreetMaps with QtWidgets/C++
  • MuratUrsavas

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  Hi,

  QQuickWidget comes to mind from your description.

  Hope it helps

• 

  Unsolved Manually Implementing Custom Widget in MainWindow
  source code custom widget circular dependencies • • Burke212

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  You can use designer or do it by code only. That's up to you.

  What strange errors do you get ?

• 

  Solved Error in HTTP request a URL and post data on it
  • isan

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  @Pablo-J.-Rogina thanks

• 

  Unsolved Building details
  • sheldon

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  Hi, welcome to the forum.

  You can open the "Compile Output" pane (Alt+4 on Windows or click on the tab on the bottom of the window). It shows all the invoked command lines and some timestamps so you can see what's compiling at the moment.

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  Unsolved Shortcuts problem in migration from QX11EmbedContainer to QWidget.createWindowContainer
  • devqore

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  No one has replied

• 

  Unsolved What is the difference between macros Q_INVOKABLE and Q_PROPERTY?
  • Ronak5

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  @Ronak5 you may want to check some of the examples in the documentation about The Property System. You'll see usage of READ, WRITE and NOTIFY for instance.

  Q_PROPERTY(Priority priority READ priority WRITE setPriority NOTIFY priorityChanged)

  And for Q_INVOKABLE and following with that example, you could imagine a method applyPriority for example so if you apply Q_INVOKABLE to it, it could be called from some other C++ classes or even from QML as mentioned before.

• 

  Unsolved Problem with MySQL driver on mac
  • Albert Huert

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  Great !

  Since you have it working now, please mark the thread as solved using the "Topic Tools" button so that other forum users may know a solution has been found :)

• 

  Unsolved TaskBar-Icon hidden when MainWindow hidden
  • Toby

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  Hi,

  Out of curiosity, do you really need several QMainWindow ?

  What is the workflow of your application ?

• 

  Unsolved How to have the most updated QT libraries?
  • lucaszanella

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  @jsulm said in How to have the most updated QT libraries?:

  @lucaszanella Try to set -DCMAKE_PREFIX_PATH=PATH_TO_YOUR_QT_VERSION/lib/cmake before calling CMake

  Hi,

  The correct call is

  cmake -D CMAKE_PREFIX_PATH=PATH_TO_YOUR_QT_VERSION/lib/cmake /path/to/your_project
• 

  Unsolved Connect a checkbox widget to a line edit to appear when toggled box
  • AXNT

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  @AXNT and when you're back from solving "error: no member named ..." you may want to take a look at your method on_advSearch_toggled()

  ui->advSearch->setCheckable(true) for sure had happened before (hopefully in the auto-generated UI code because you checked "checkable" property for the QCheckBox widget when you placed it in the UI. No need to do that there. No need to connect(...) any signal from QCheckBox object to QLineEdit object.
  Just do (pseudo-code): ui->rmaEdit->setVisible(checked);

  this way when the on_advSearch_toggled() method is called because the user checked or unchecked the box, the QLineEdit widget will be visible (checked is true) or not visible (checked is false)

  PS: next time, please don't paste an image of your code, just surround it with the code tag (icon </>) to get something like this, that you'll fill out with your code snippet...

  ``` //your code here ```
• 

  Unsolved qt map import or display map
  • s002wjh

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  thx, ill take a look at

• 

  Unsolved How draw customize toolbar button in QT
  • Aleskey

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  Hi and welcome to the forums
  The normal QToolButton can do it.
  You need
  a icon and use
  https://doc.qt.io/qt-5/qtoolbutton.html#setMenu
  to give it the popup menu
  and for building the menu you want to set
  setCheckable(true) for the QAction you give to menu if you need the checkmark feature.

• 

  Unsolved migrate old application
  • aminemaar

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  I have run into "old apps" before that were difficult to change "delicate". A lot of the time the app was designed in a flawed structure. The structure used to build the program was not robust and made things difficult to change. In cases where the app had significant need to be used in the future it was often the shortest path to come up with a list of requirements, functions, etc and create a design document. From this a new app was written with lessons learned of "how not to do things". In the long run it was the shortest route.

  Your mileage may vary. Nobody has a crystal ball.

• 

  Unsolved QLocalSocket doesn't emit readyRead
  • Ananym

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  Welp. That works fine.
  And when I amended it so the server sends its response inside readyRead, that works fine.
  And when I changed the sending/receiving method to match the more explicit serialization my wrapper uses, that - frustratingly - worked fine.

  Hm! I hope to test it with the same wrapper library I had been using but integrating it is going to take me some time to stumble around. The server application I'm adding to already has quite a busy event loop, so it's hard to say what else might play into it. Thanks a lot for your help, having such an elegant minimal solution does make things easier and this goes a long way to exclude possible factors.

• 

  Unsolved Timer Cannot Stop..?
  • PrAnit

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  Hi
  timer is a single shot so should not be running.
  and you should call
  timer2->Stop();

  in STOP button.

• 

  Unsolved Segmentation Fault when reading from a TCPSocket
  • onurcevik

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  Hi,

  One small note, use qobject_cast when casting QObject based classes. This will return a null pointer if either the source is already a null pointer or not from the correct class.

• 

  Unsolved QFileDialog::getOpenFileName
  • meikelneit

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  @meikelneit
  Hi
  with QFileDialog::getOpenFileName static call, if user press Cancel or close X the
  returned string will be empty.

  QString l_filePath = QFileDialog::getOpenFileName(this,tr("open directory"),QDir::homePath(),("*.db")); if ( ! l_filePath.isEmpty() ) { // if user did select something .... }
• 

  Unsolved Failure to return file paths in server 2008 qt QDirIterator
  • ErfanCoder

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  @mrjj said in Failure to return file paths in server 2008 qt QDirIterator:

  Hi and welcome to the forums.
  Are you certain you have rights to enumerate folder in c:\ for the user account on the server ?

  yes ,
  im using qt 5.8 msvc2015

• 

  Unsolved QJSEngine, how to expose C++ enum to a JavaScript?
  • Alhasni

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  Hi @Alhasni,

  According to https://doc.qt.io/qt-5/qjsengine.html#qobject-integration I guess you need to use QJSEngine::newQMetaObject():

  QJSValue enumObjectValue = _jsEngine.newQMetaObject(_controller->metaObject()); _jsEngine.globalObject().setProperty("controller", enumObjectValue);
• 

  Unsolved Need to use QCryptographicHash and convert an STL function
  • vivian

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  @jsulm Thank you for that.. I just did a straight up copy.

  Now just stuck at the last part where the SHA1 and then converting to base64

  string utf8String = wstring_to_utf8(keyaccessGuid); unsigned char digestStr2[SHA_DIGEST_LENGTH]; SHA1((unsigned char*)utf8String.c_str(), strlen(utf8String.c_str()), (unsigned char*)&digestStr2); char* utf8StrSha1Base64 = convertToBase64(digestStr2, SHA_DIGEST_LENGTH); string sha1DataStr(utf8StrSha1Base64); //Remove all characters except alphabets removeForbiddenChar(&sha1DataStr);

  This is what I am trying to do.

  { ... QString utf8String = keyaccessGuid.toUtf8(); QByteArray resBytes(utf8String.toStdString().c_str()); QCryptographicHash sha(QCryptographicHash::Sha1); sha.addData(resBytes); QByteArray shaBytes = sha.result(); qDebug()<<"Resulting Hash is "; QString resHash = base64_encode(shaBytes); qDebug()<<resHash ; } QString base64_encode(QByteArray ba){ return ba.toBase64(); } QByteArray base64_decode(QByteArray ba){ return QByteArray::fromBase64(ba); }

  I am hoping I am on the right track.

• 

  Unsolved C++ signal QML slot with QObject as parameter but sometimes QML receives null
  • Prasad_Socionext

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