[Solved] Adding a qwtPlot to a layout

[cl90]

Hi!

What i'm trying to do should be pretty easy. But somehow it doesn't work.
All i'm trying to do is to add a qwtPlot to an qt application, without launching the plot in its own application.
Every time i try, i end up with 2 application windows (one for the application and one for the plot) or with no application (because it crashes).
I tired this for quiet some time without any progress, so maybe you can help me out.

If i run this somewhere in my code i end up with 2 application windows. (not what i want)

QwtPlot* plot = new QwtPlot();
    plot->setTitle( "Plot Demo" );
    plot->setCanvasBackground( Qt::white );
    plot->setAxisScale( QwtPlot::yLeft, 0.0, 10.0 );
    plot->insertLegend( new QwtLegend() );
    [...]
    plot->show();

QwtPlot* plot = new QwtPlot();
    plot->setTitle( "Plot Demo" );
    plot->setCanvasBackground( Qt::white );
    plot->setAxisScale( QwtPlot::yLeft, 0.0, 10.0 );
    plot->insertLegend( new QwtLegend() );
    [...]
    plot->show();

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What i want is to add a plot to a specified layout inside my application.
every time i try to add a qwtPlot as a widget, my application crashes.

QwtPlot* plot = new QwtPlot();
    [...]
    ui->horizontalLayout->addWidget(plot);

QwtPlot* plot = new QwtPlot();
    [...]
    ui->horizontalLayout->addWidget(plot);

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Is this even Possible? i cant even find anything about this.