Qt自定义带游标的slider，在滑块正上方显示当前值

[{"title":"（8个子文件5KB）Qt自定义带游标的slider，在滑块正上方显示当前值","children":[{"title":"testSlider","children":[{"title":"mainwindow.ui <span style='color:#111;'>2.61KB</span>","children":null,"spread":false},{"title":"mainwindow.cpp <span style='color:#111;'>233B</span>","children":null,"spread":false},{"title":"mycustomslider.h <span style='color:#111;'>485B</span>","children":null,"spread":false},{"title":"testSlider.pro.user <span style='color:#111;'>23.33KB</span>","children":null,"spread":false},{"title":"main.cpp <span style='color:#111;'>183B</span>","children":null,"spread":false},{"title":"mycustomslider.cpp <span style='color:#111;'>1.30KB</span>","children":null,"spread":false},{"title":"mainwindow.h <span style='color:#111;'>313B</span>","children":null,"spread":false},{"title":"testSlider.pro <span style='color:#111;'>433B</span>","children":null,"spread":false}],"spread":true}],"spread":true}]