1.求指定宽度的文本的高度，2.ubuntu下ping ipv6，3.git提示：终止提交因为提交说明为空

1.如何求指定宽度的文本的高度

paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    QString text = "Invalid parameter passed to C runtime function.";
    QFontMetrics fm(qApp->font());
 
    QTextDocument doc(text);
    doc.setDefaultFont(painter.font());
    doc.setTextWidth(100);
    doc.adjustSize();
    painter.fillRect(QRect(QPoint(0, 0), doc.size().toSize()), Qt::yellow);
    doc.drawContents(&painter);
}

更新方法

QFontMetrics(font).boundingRect(QRect(0, 0, option.rect.width(), 0), Qt::AlignCenter|Qt::TextWordWrap, text);

2.ubuntu下ping ipv6

服务端

    QTcpServer *server = new QTcpServer(this);
    server->listen(QHostAddress("FE80::AF72:573C:4B61:CABD%eno1"), 8080);
    connect(server, &QTcpServer::newConnection, this, [=](){qDebug() << "new connection" << server->nextPendingConnection()->peerAddress();});

客户端

 QTcpSocket tcp;
 tcp.connectToHost(QHostAddress("FE80::AF72:573C:4B61:CABD%eno1"), 8080);
 tcp.waitForConnected();

终端ping

3.Ubuntu下git提示：终止提交因为提交说明为空

这么简单的问题居然搜索了一会儿，现在的网络环境越来越差了。

解决方法：

gedit:

git config --global core.editor "gedit -s"

the paramater "-s " means set the gedit mode to "standalone"

Sublime Text 2

git config --global core.editor "subl -w"

the paramater "-w" means return until the file was closed.

参考：https://www.cnblogs.com/maadiah/archive/2012/02/27/2369931.html