QComboBox输入自动提示功能（仿Google搜索提示）

#include "qcomboxwidget.h" #include "ui_qcomboxwidget.h" #include <QKeyEvent> #include <QLineEdit> QComboxWidget::QComboxWidget(QWidget *parent) : QWidget(parent), ui(new Ui::QComboxWidget) { ui->setupUi(this); ui->comboBox->lineEdit()->setText(""); ui->comboBox->lineEdit()->setClearButtonEnabled(true); ui->listWidget->setSizeAdjustPolicy(QListView::AdjustToContents); ui->listWidget->setVisible(false); setMinimumWidth(220); adjustSize(); // setWindowFlags(Qt::FramelessWindowHint | Qt::WindowSystemMenuHint | Qt::WindowMinMaxButtonsHint); connect(ui->comboBox->lineEdit(),SIGNAL(textChanged (const QString & )),this,SLOT(OnRadarChange(const QString & ))); vtCity.push_back("beijing1"); vtCity.push_back("beijing2"); vtCity.push_back("beijing3"); vtCity.push_back("beijing4"); vtCity.push_back("beijing5"); vtCity.push_back("beijing6"); vtCity.push_back("beijing7"); vtCity.push_back("beijing8"); vtCity.push_back("beijing9"); vtCity.push_back("bengbu"); vtCity.push_back("baise"); vtCity.push_back("hailaer"); } QComboxWidget::~QComboxWidget() { delete ui; } void QComboxWidget::keyPressEvent ( QKeyEvent * keyevent ) { if(QApplication::focusWidget() != ui->comboBox->lineEdit() || ui->listWidget->count() == 0)return; int uKey = keyevent->key(); Qt::Key key = static_cast<Qt::Key>(uKey); int iIndex = ui->listWidget->currentRow (); if(key == Qt::Key_Up) { iIndex--; if(iIndex < 0) iIndex = 0; QListWidgetItem *pItem = ui->listWidget->item(iIndex); // pItem->setForeground(Qt::red); ui->listWidget->setCurrentItem(pItem); } else if (key == Qt::Key_Down) { iIndex++; if(iIndex >= ui->listWidget->count()) iIndex = ui->listWidget->count() - 1; QListWidgetItem *pItem = ui->listWidget->item(iIndex); ui->listWidget->setCurrentItem(pItem); } else if (key == Qt::Key_Enter || key == Qt::Key_Return) { ui->comboBox->lineEdit()->setText(ui->listWidget->currentItem()->text()); } } void QComboxWidget::OnRadarChange(const QString &strText) { ui->listWidget->clear(); if (!ui->comboBox->lineEdit()->text().isEmpty()) { for(int i = 0;i < vtCity.size();++i) { if (vtCity[i].indexOf(strText) != -1) { ui->listWidget->addItem(vtCity[i]); } } } if (ui->listWidget->count() > 0) { ui->listWidget->setVisible(true); } else { ui->listWidget->setVisible(false); setMaximumHeight(ui->comboBox->lineEdit()->height()); adjustSize(); } }