programin in the qt creator

[squidge]

Slot does not run because you use connect incorrectly.

ui.pushButton->connect(ui.pushButton,SIGNAL(clicked()),ui.comboB ox_3,SLOT(browse()));

ui.pushButton->connect(ui.pushButton,SIGNAL(clicked()),ui.comboB ox_3,SLOT(browse()));

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is not good.

Please see the examples.

I also do not understand slot browse() of comboBox_3. According to your code, this should be MainWindow, as thats where browse lives?