Qt浅谈之四十一QLineEdit的新样式和补全历史记录

本文主要是介绍Qt浅谈之四十一QLineEdit的新样式和补全历史记录，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

一、简介

利用背景图片设计出QLineEdit新的样式，起到美化界面的效果，并增加自动补全历史记录的功能，就可以作为一个完整的库。

二、详解

1、知识点

（1）切换QLineEdit的背景

void InnerLineEdit::setNormal()
{setText("");setTextMargins(-5,0,this->height(),0);    //solve the cursor problemsetStyleSheet("background-image:url(:/searchInput.png);border:1px solid #536874;");
}void InnerLineEdit::setSearching()
{setTextMargins(0,0,this->height(),0);setStyleSheet("background-image:url(:/searchInput_click.png);border:1px solid #536874;");
}

（2）QLineEdit模糊匹配

    QCompleter *completer = new QCompleter(this);listModel = new QStringListModel(valueList, this);completer->setCaseSensitivity(Qt::CaseInsensitive);completer->setModel(listModel);this->setCompleter(completer);

（3）记录历史输入

connect(this, SIGNAL(editingFinished()), this, SLOT(editComplete()));

void InnerLineEdit::editComplete()
{QString text = this->text();if(QString::compare(text, QString("")) != 0) {bool flag = valueList.contains(text, Qt::CaseInsensitive);if(!flag) {addValue(text);}}
}

2、完整代码

（1）searchlineedit.h

#ifndef SEARCHLINEEDIT_H
#define SEARCHLINEEDIT_H#include <QtGui>
class InnerLineEdit;
class SearchLineEdit : public QWidget
{Q_OBJECTpublic:SearchLineEdit(QWidget *parent = 0);~SearchLineEdit();protected:void resizeEvent(QResizeEvent *event);signals:void searchTextChanged(QString);private slots:void textChange(QString text);void editClicked();void btnClicked();private:InnerLineEdit *lineEdit;QPushButton *btn;
};class InnerLineEdit : public QLineEdit
{Q_OBJECTpublic:explicit InnerLineEdit(QWidget *parent = 0);void setNormal();void setSearching();void addValue(const QString &value);protected:void focusInEvent(QFocusEvent *event);void focusOutEvent(QFocusEvent *event);signals:void pressed();private slots:void editComplete();private:QStringList valueList;QStringListModel *listModel;
};#endif // SEARCHLINEEDIT_H

（2）searchlineedit.cpp

#include "searchlineedit.h"SearchLineEdit::SearchLineEdit(QWidget *parent): QWidget(parent)
{lineEdit = new InnerLineEdit(this);lineEdit->move(8,38);lineEdit->resize(168,23);connect(lineEdit,SIGNAL(textChanged(QString)),this,SLOT(textChange(QString)));connect(lineEdit,SIGNAL(pressed()),this,SLOT(editClicked()));btn = new QPushButton(this);btn->setFocusPolicy(Qt::NoFocus);btn->setCursor(Qt::PointingHandCursor);btn->resize(14,14);btn->move(157,42);btn->setStyleSheet("QPushButton{background-color:transparent;border:0px;}");btn->setFocusPolicy(Qt::NoFocus);btn->setVisible(false);connect(btn,SIGNAL(clicked()),this,SLOT(btnClicked()));this->setFocus();lineEdit->addValue("C");lineEdit->addValue("C++");lineEdit->addValue("Python");lineEdit->addValue("Php");lineEdit->addValue("Perl");lineEdit->addValue("Qt");
}SearchLineEdit::~SearchLineEdit()
{}void SearchLineEdit::resizeEvent(QResizeEvent *event)
{move((QApplication::desktop()->width() - width())/2,  (QApplication::desktop()->height() - height())/2);QWidget::resizeEvent(event);
}void SearchLineEdit::textChange(QString text)
{emit searchTextChanged(text);
}void SearchLineEdit::editClicked()
{lineEdit->setSearching();btn->setVisible(true);
}void SearchLineEdit::btnClicked()
{lineEdit->setNormal();btn->setVisible(false);this->setFocus();
}/*******************************/
InnerLineEdit::InnerLineEdit(QWidget *parent): QLineEdit(parent)
{setTextMargins(0,0,this->height(),0);setStyleSheet("background-image:url(:/searchInput.png);border:1px solid #536874;");QCompleter *completer = new QCompleter(this);listModel = new QStringListModel(valueList, this);completer->setCaseSensitivity(Qt::CaseInsensitive);completer->setModel(listModel);this->setCompleter(completer);connect(this, SIGNAL(editingFinished()), this, SLOT(editComplete()));}void InnerLineEdit::setNormal()
{setText("");setTextMargins(-5,0,this->height(),0);    //solve the cursor problemsetStyleSheet("background-image:url(:/searchInput.png);border:1px solid #536874;");
}void InnerLineEdit::setSearching()
{setTextMargins(0,0,this->height(),0);setStyleSheet("background-image:url(:/searchInput_click.png);border:1px solid #536874;");
}void InnerLineEdit::addValue(const QString &value)
{valueList.append(value);listModel->setStringList(valueList);
}void InnerLineEdit::focusInEvent(QFocusEvent *event)
{emit pressed();QLineEdit::focusInEvent(event);
}void InnerLineEdit::focusOutEvent(QFocusEvent *event)
{QLineEdit::focusInEvent(event);
}void InnerLineEdit::editComplete()
{QString text = this->text();if(QString::compare(text, QString("")) != 0) {bool flag = valueList.contains(text, Qt::CaseInsensitive);if(!flag) {addValue(text);}}
}

（3）main.cpp

#include "searchlineedit.h"
#include <QApplication>int main(int argc, char *argv[])
{QApplication a(argc, argv);SearchLineEdit w;w.show();return a.exec();
}

（4）编译运行