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，它可能会出现在工具按钮下。

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lineEdits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

最初的博客文章现在已经消失，但Trolltech once posted an example of a clear button为Qt 4。

Results

行编辑没有文字：

使用一些文本进行行编辑（出现按钮）：

行编辑完整的文本（不在按钮下面）：

Source

lineedit.h

/****************************************************************************
**
** Copyright (c) 2007 Trolltech ASA <[email protected]>
**
** 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

lineedit.cpp

/****************************************************************************
**
** Copyright (c) 2007 Trolltech ASA <[email protected]>
**
** 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());
}

Answer 2

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 3

一旦我实现了这样的解决方案：

// LineEdit.h

#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:
    QToolButton *furfurIcon;
};

#endif // LINEEDIT_H

// LineEdit.cpp

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

LineEdit::LineEdit(QWidget *parent)
    : QLineEdit(parent)
{
    furfurIcon = new QToolButton(this);

    QPixmap pixmap(":/root/your_icon");
    furfurIcon->setIcon(QIcon(pixmap));
    furfurIcon->setIconSize(pixmap.size());
    furfurIcon->setCursor(Qt::ArrowCursor);
    furfurIcon->setStyleSheet("QToolButton
                              "{"
                              "border: none; padding: 0px;"
                              "}");

    setStyleSheet(QString("QLineEdit"
                          "{"
                          "border: 1px solid;"
                          "border-color: rgb(148, 168, 199);"
                          "border-radius: 10px;"
                          "background: white;"
                          "padding-left: %1px;"
                          "}").arg(furfurIcon->sizeHint().width() - 4));

    setMinimumSize(0, 25);
}

void LineEdit::resizeEvent(QResizeEvent *)
{
    QSize sz = furfurIcon->sizeHint();
    furfurIcon->move(rect().left(), (rect().bottom() + 1 - sz.height()) / 2);
}

QToolButton的位置在resizeEvent中处理。如果有多个，则必须调整其坐标。您也可以修改它以使用布局。这里没有文字重叠。