QLineEdit带有自定义按钮

Question

我需要实现LineEdit小部件,可以在文本区域的右端添加工具按钮.我知道有两种方法可以做到这一点但两种解决方案看起来都很丑

1)添加工具按钮作为QLineEdit的子窗口小部件,并处理resizeEvent以正确定位它们.主要缺点是如果文本足够长,它可能出现在工具按钮下.

2)另一个解决方案是将行编辑和按钮放在框架内并覆盖样式以隐藏线条框架并使QFrame看起来像QLineEdit.

我需要一种最好的方法来实现这样的小部件.我的小部件也应该是风格意识.

Answer 1

从Qt 5.2开始,可以使用QLineEdit::addAction(...)插入自定义按钮.(Qt Docs)

示例(假设我们在MyClass的定义中):

QLineEdit *myLineEdit = new QLineEdit(this);
QAction *myAction = myLineEdit->addAction(QIcon("test.png"), QLineEdit::TrailingPosition);
connect(myAction, &QAction::triggered, this, &MyClass::onActionTriggered);

Answer 2

原来的博文现在不见了，但奇趣科技曾经发布过一个Qt 4清除按钮的例子。

结果

没有文字的行编辑：

带有一些文本的行编辑（出现按钮）：

全文本行编辑（不在按钮下方）：

来源

行编辑器

/****************************************************************************
**
** Copyright (c) 2007 Trolltech ASA <info@trolltech.com>
**
** Use, modification and distribution is allowed without limitation,
** warranty, liability or support of any kind.
**        
****************************************************************************/

#ifndef LINEEDIT_H
#define LINEEDIT_H

#include <QLineEdit>

class QToolButton;

class LineEdit : public QLineEdit
{
    Q_OBJECT

public:
    LineEdit(QWidget *parent = 0);

protected:
    void resizeEvent(QResizeEvent *);

private slots:
    void updateCloseButton(const QString &text);

private:
    QToolButton *clearButton;
};

#endif // LIENEDIT_H

行编辑器

/****************************************************************************
**
** Copyright (c) 2007 Trolltech ASA <info@trolltech.com>
**
** Use, modification and distribution is allowed without limitation,
** warranty, liability or support of any kind.
**
****************************************************************************/

#include "lineedit.h"
#include <QToolButton>
#include <QStyle>

LineEdit::LineEdit(QWidget *parent)
    : QLineEdit(parent)
{
    clearButton = new QToolButton(this);
    QPixmap pixmap("fileclose.png");
    clearButton->setIcon(QIcon(pixmap));
    clearButton->setIconSize(pixmap.size());
    clearButton->setCursor(Qt::ArrowCursor);
    clearButton->setStyleSheet("QToolButton { border: none; padding: 0px; }");
    clearButton->hide();
    connect(clearButton, SIGNAL(clicked()), this, SLOT(clear()));
    connect(this, SIGNAL(textChanged(const QString&)), this, SLOT(updateCloseButton(const QString&)));
    int frameWidth = style()->pixelMetric(QStyle::PM_DefaultFrameWidth);
    setStyleSheet(QString("QLineEdit { padding-right: %1px; } ").arg(clearButton->sizeHint().width() + frameWidth + 1));
    QSize msz = minimumSizeHint();
    setMinimumSize(qMax(msz.width(), clearButton->sizeHint().height() + frameWidth * 2 + 2),
                   qMax(msz.height(), clearButton->sizeHint().height() + frameWidth * 2 + 2));
}

void LineEdit::resizeEvent(QResizeEvent *)
{
    QSize sz = clearButton->sizeHint();
    int frameWidth = style()->pixelMetric(QStyle::PM_DefaultFrameWidth);
    clearButton->move(rect().right() - frameWidth - sz.width(),
                      (rect().bottom() + 1 - sz.height())/2);
}

void LineEdit::updateCloseButton(const QString& text)
{
    clearButton->setVisible(!text.isEmpty());
}