写在前面

这里自定义一个搜索控件，通过自定义LineEdit的textChange信号，搜索指定内容，并以QCheckBox的方式显示在QListWidget中。

开发版本

Qt: 5.15.2
Qt: Creator10.0.2

编译环境：msvc2019_64bit release

效果

代码

自定义LineEdit，带前缀图标。

//MLineEdit.h
#ifndef MLINEEDIT_H
#define MLINEEDIT_H#include <QLineEdit>
#include <QHBoxLayout>class MLineEdit : public QLineEdit
{Q_OBJECT
public:explicit MLineEdit(QWidget *parent = nullptr);signals:private:QHBoxLayout* layout;};#endif // MLINEEDIT_H

//MLineEdit.cpp
#include "mlineedit.h"
#include <QLabel>
#include <QDebug>MLineEdit::MLineEdit(QWidget *parent): QLineEdit{parent}
{layout = new QHBoxLayout(this);QLabel* prefixIcon = new QLabel(this);QPixmap pix(":/icons/search.svg");prefixIcon->setPixmap(pix);prefixIcon->setFixedSize(pix.size());layout->addWidget(prefixIcon);layout->setContentsMargins(1, 1, 1, 1);layout->addStretch();layout->setDirection(QBoxLayout::LeftToRight);qDebug() << font();setFont(QFont("SimSun", 15));setTextMargins(prefixIcon->width(), 1, 1, 1);QString qss = QString("QLineEdit{border:1px solid gray;border-radius:10px;}");setStyleSheet(qss);
}

应用实现：

//MyWidgets.h
#ifndef MYWIDGETS_H
#define MYWIDGETS_H#include <QWidget>QT_BEGIN_NAMESPACE
namespace Ui { class MyWidgets; }
QT_END_NAMESPACEclass MyWidgets : public QWidget
{Q_OBJECTpublic:MyWidgets(QWidget *parent = nullptr);~MyWidgets();public slots:void textChangeSlot(const QString& text);private:Ui::MyWidgets *ui;QStringList qlCheck;
};
#endif // MYWIDGETS_H

//MyWidgets.cpp
#include "mywidgets.h"
#include "ui_mywidgets.h"#include <QPushButton>
#include <QIcon>
#include <QCheckBox>
#include <QDebug>
#include <QListWidgetItem>
#include "mlineedit.h"MyWidgets::MyWidgets(QWidget *parent): QWidget(parent), ui(new Ui::MyWidgets)
{ui->setupUi(this);qlCheck << tr("whatsApp") << tr("weChat") << tr("QQ") << tr("Telegram") << tr("twitter");connect(ui->lineEdit, &QLineEdit::textChanged, this, &MyWidgets::textChangeSlot);
}MyWidgets::~MyWidgets()
{delete ui;
}void MyWidgets::textChangeSlot(const QString& text)
{QString qsInput = ui->lineEdit->text();qDebug() << qsInput;ui->listWidget->clear();if (qsInput.isEmpty()){return;}for (QString qs : qlCheck){if (qs.contains(qsInput, Qt::CaseInsensitive)){QCheckBox* checkBox = new QCheckBox(this);checkBox->setText(qs);QListWidgetItem* listItem = new QListWidgetItem();ui->listWidget->addItem(listItem);ui->listWidget->setItemWidget(listItem, checkBox);}}
}

ui布局及完整代码可见github仓库：https://github.com/SNAKEpg12138/SearchWidget

总结

使用样式表实现带前缀图标的LineEdit，并通过一个简单的搜索控件应用。