Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. QLabel pixmap not clearing
Forum Updated to NodeBB v4.3 + New Features

QLabel pixmap not clearing

Scheduled Pinned Locked Moved General and Desktop
qt 4.8qpixmapqlabeltransparency
1 Posts 1 Posters 2.9k Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • T Offline
    T Offline
    Tymer
    wrote on last edited by
    #1

    Hello, I'm having QPixmap issues yet again....
    The documentation has led me to believe that the pixmap of a QLabel is cleared after QLabel::setPixmap. However, this does not seem to be the case. I have two images, but for this example I'm just going to do an image filled with red for one. The other will be called redandblue.png. I want to switch between red and redandblue.png, but redandblue.png has a transparent background. When I try and bring it up after the red, I just see some blue lines on a red background. This makes some sense, since redandblue.png has a transparent background. However, shouldn't the red be gone if I'm doing (psuedocode) label->setPixmap(redandblue.png)?

    Here's some code: (note: there are some redundant lines that I'm leaving to show that they aren't helpful, and some lines omitted for brevity)

    void myWidget::myWidget()
    {
        // QPixmap redandblue in header
        redandblue = QPixmap(":/path/to/redandblue.png");
    
    }
    

    Thanks in advance.
    void myWidget::setRed()
    {

        QImage img(120, 120, QImage::Format_ARGB32);
        img.fill(Qt::red);
        ui->myLabel->setPixmap(QPixmap::fromImage(img));
        this->repaint();
        this->update();
    }
    
    void myWidget::setRedAndBlue()
    {
        ui->myLabel->setPixmap(redandblue);
        this->repaint();
        ui->myLabel->update();
    }
    
    1 Reply Last reply
    0

    • Login

    • Login or register to search.
    • First post
      Last post
    0
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Groups
    • Search
    • Get Qt Extensions
    • Unsolved