Qt小程序(三)-继承Qt窗口部件创建自定义部件

前言

人都是有两面性的，当你有价值的时候(入了别人眼的时候)，就会得到不同的待遇！所以，没有入别人眼的时候，自然就不会被认真对待！努力，学习，人真的可以选择自己的层次！

制作自定义的窗口部件-继承Qt已有的窗口部件

在项目上右键添加新文件，然后建立里一个hexspinbox类，就会自动在头文件目录和源文件目录生成hexspinbox.cpp和hexspinbox.h。

Qt代码

#include "dialog.h"
#include <QApplication>
#include "hexspinbox.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
//    Dialog w;
//    w.show();
    HexSpinBox  h;
    h.show();

    return a.exec();
}

hexspinbox.h

#ifndef HEXSPINBOX_H
#define HEXSPINBOX_H

#include <QSpinBox>
class QRegExpValidator;

class HexSpinBox : public QSpinBox
{
public:
    HexSpinBox(QWidget* parent = 0);
protected:
    QValidator::State validate(QString &input, int &pos) const;
    int valueFromText(const QString &text) const;
    QString textFromValue(int val) const;
private:
    QRegExpValidator *validator;
};

#endif // HEXSPINBOX_H

hexspinbox.cpp

#include "hexspinbox.h"
#include <QtWidgets>

HexSpinBox::HexSpinBox(QWidget* parent):QSpinBox(parent)
{
    setRange(0, 255);
    validator = new QRegExpValidator(QRegExp("[0-9A-Fa-f]{1,8}"), this);

}

// when we input a value, validate() will be called automatically
// To decide whether the value is good
QValidator::State HexSpinBox::validate(QString &input, int &pos) const
{
    return validator->validate(input, pos);
}

// when the value is going to be show, we should transform it
// into hex, also you can make it Upper
QString HexSpinBox::textFromValue(int value) const
{
    return QString::number(value, 16).toUpper();
}

// Qt will save the value as Int. so when we input a hex
// Qt will call valueFromText to transform hex to Int
int HexSpinBox::valueFromText(const QString &text) const
{
    bool ok;
    return text.toInt(&ok, 16);
}