1. void udp_server::on_lineEdit_textEdited()
{
ui->pushButton->setEnabled(ui->lineEdit->hasAcceptableInput());
}
2. 撤销ctrl+z
3.信号槽函数定义
signals:
void readyRead();
private slots:
void on_pushButton_clicked();
原文：https://www.cnblogs.com/xpylovely/p/10899905.html