Qt文件拷贝带进度条显示

[{"title":"（8个子文件7KB）Qt文件拷贝带进度条显示","children":[{"title":"FileCopy","children":[{"title":"FileCopy.pro.user <span style='color:#111;'>23.25KB</span>","children":null,"spread":false},{"title":"mainwindow.ui <span style='color:#111;'>5.89KB</span>","children":null,"spread":false},{"title":"mainwindow.cpp <span style='color:#111;'>3.18KB</span>","children":null,"spread":false},{"title":"main.cpp <span style='color:#111;'>183B</span>","children":null,"spread":false},{"title":"mainwindow.h <span style='color:#111;'>592B</span>","children":null,"spread":false},{"title":"FileCopy.pro <span style='color:#111;'>423B</span>","children":null,"spread":false},{"title":"copythread.cpp <span style='color:#111;'>3.45KB</span>","children":null,"spread":false},{"title":"copythread.h <span style='color:#111;'>930B</span>","children":null,"spread":false}],"spread":true}],"spread":true}]