Qt开源作品17-IP地址输入控件

一、前言

这个IP地址输入框控件，估计写烂了，网上随便一搜索，保证一大堆，估计也是因为这个控件太容易了，非常适合新手练手，一般的思路都是用4个qlineedit控件拼起来，然后每个输入框设置正则表达式过滤只能输入3位数字，然后安装事件过滤器识别回车自动跳到下一个输入框。关于如何设置正则表达式过滤，这个可以搜索查到，本人也不大懂这个规则，貌似还有专门的书籍专门介绍正则表达式，可能这块非常强大。

主要功能：

1. 可设置IP地址,自动填入框
2. 可清空IP地址
3. 支持按下小圆点自动切换
4. 支持退格键自动切换
5. 支持IP地址过滤
6. 可设置背景色/边框颜色/边框圆角角度

二、代码思路

IPAddress::IPAddress(QWidget *parent) : QWidget(parent)
{
    bgColor = "#FFFFFF";
    borderColor = "#A6B5B8";
    borderRadius = 3;

    //用于显示小圆点的标签,居中对齐
    labDot1 = new QLabel;
    labDot1->setAlignment(Qt::AlignCenter);
    labDot1->setText(".");

    labDot2 = new QLabel;
    labDot2->setAlignment(Qt::AlignCenter);
    labDot2->setText(".");

    labDot3 = new QLabel;
    labDot3->setAlignment(Qt::AlignCenter);
    labDot3->setText(".");

    //用于输入IP地址的文本框,居中对齐
    txtIP1 = new QLineEdit;
    txtIP1->setObjectName("txtIP1");
    txtIP1->setAlignment(Qt::AlignCenter);
    txtIP1->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    connect(txtIP1, SIGNAL(textChanged(QString)), this, SLOT(textChanged(QString)));

    txtIP2 = new QLineEdit;
    txtIP2->setObjectName("txtIP2");
    txtIP2->setAlignment(Qt::AlignCenter);
    txtIP2->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    connect(txtIP2, SIGNAL(textChanged(QString)), this, SLOT(textChanged(QString)));

    txtIP3 = new QLineEdit;
    txtIP3->setObjectName("txtIP3");
    txtIP3->setAlignment(Qt::AlignCenter);
    txtIP3->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    connect(txtIP3, SIGNAL(textChanged(QString)), this, SLOT(textChanged(QString)));

    txtIP4 = new QLineEdit;
    txtIP4->setObjectName("txtIP4");
    txtIP4->setAlignment(Qt::AlignCenter);
    txtIP4->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    connect(txtIP4, SIGNAL(textChanged(QString)), this, SLOT(textChanged(QString)));

    //设置IP地址校验过滤
    QRegExp regExp("(2[0-5]{2}|2[0-4][0-9]|1?[0-9]{1,2})");
    QRegExpValidator *validator = new QRegExpValidator(regExp, this);
    txtIP1->setValidator(validator);
    txtIP2->setValidator(validator);
    txtIP3->setValidator(validator);
    txtIP4->setValidator(validator);

    //绑定事件过滤器,识别键盘按下
    txtIP1->installEventFilter(this);
    txtIP2->installEventFilter(this);
    txtIP3->installEventFilter(this);
    txtIP4->installEventFilter(this);

    QFrame *frame = new QFrame;
    frame->setObjectName("frameIP");

    QStringList qss;
    qss.append(QString("QFrame#frameIP{border:1px solid %1;border-radius:%2px;}").arg(borderColor).arg(borderRadius));
    qss.append(QString("QLabel{min-15px;background-color:%1;}").arg(bgColor));
    qss.append(QString("QLineEdit{background-color:%1;border:none;}").arg(bgColor));
    qss.append(QString("QLineEdit#txtIP1{border-top-left-radius:%1px;border-bottom-left-radius:%1px;}").arg(borderRadius));
    qss.append(QString("QLineEdit#txtIP4{border-top-right-radius:%1px;border-bottom-right-radius:%1px;}").arg(borderRadius));
    frame->setStyleSheet(qss.join(""));

    QVBoxLayout *verticalLayout = new QVBoxLayout(this);
    verticalLayout->setMargin(0);
    verticalLayout->setSpacing(0);
    verticalLayout->addWidget(frame);

    //将控件按照横向布局排列
    QHBoxLayout *layout = new QHBoxLayout(frame);
    layout->setMargin(0);
    layout->setSpacing(0);
    layout->addWidget(txtIP1);
    layout->addWidget(labDot1);
    layout->addWidget(txtIP2);
    layout->addWidget(labDot2);
    layout->addWidget(txtIP3);
    layout->addWidget(labDot3);
    layout->addWidget(txtIP4);
}

bool IPAddress::eventFilter(QObject *watched, QEvent *event)
{
    if (event->type() == QEvent::KeyPress) {
        QLineEdit *txt = (QLineEdit *)watched;
        if (txt == txtIP1 || txt == txtIP2 || txt == txtIP3 || txt == txtIP4) {
            QKeyEvent *key = (QKeyEvent *)event;

            //如果当前按下了小数点则移动焦点到下一个输入框
            if (key->text() == ".") {
                this->focusNextChild();
            }

            //如果按下了退格键并且当前文本框已经没有了内容则焦点往前移
            if (key->key() == Qt::Key_Backspace) {
                if (txt->text().length() <= 1) {
                    this->focusNextPrevChild(false);
                }
            }
        }
    }

    return QWidget::eventFilter(watched, event);
}

三、效果图

四、开源主页

以上作品完整源码下载都在开源主页，会持续不断更新作品数量和质量，欢迎各位关注。

1. 国内站点：https://gitee.com/feiyangqingyun/QWidgetDemo
2. 国际站点：https://github.com/feiyangqingyun/QWidgetDemo
3. 个人主页：https://blog.csdn.net/feiyangqingyun
4. 知乎主页：https://www.zhihu.com/people/feiyangqingyun/