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-width: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/
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