#ifndef WIDGET_H

#define WIDGET_H

#include <QWidget>

class Widget : public QWidget

{

    Q_OBJECT

public:

    Widget(QWidget *parent = 0);

    ~Widget();

public slots:

    void showColor();

};

#endif // WIDGET_H

#include "widget.h"

#include<QColor>

#include<QColorDialog>

#include<QPushButton>

#include<QPalette> //调色板

#include<QLabel>

#include<QHBoxLayout>

Widget::Widget(QWidget *parent)

    : QWidget(parent)

{

    this->resize(600,480);

    QPalette qpalette=this->palette();

    QHBoxLayout *s=new QHBoxLayout(this);

    qpalette.color( QPalette::WindowText);

    qpalette.setColor(QPalette::WindowText,QColor(255,0,0));

    qpalette.setColor(QPalette::Background,QColor("#0f8Fb0"));

    this->setPalette(qpalette);

    QPushButton *qp=new QPushButton("打开",this);

    QLabel* ql=new QLabel("打开",this);

    s->addWidget(qp);

    s->addWidget(ql);

   connect(qp,SIGNAL(clicked()),this,SLOT(showColor()));

}

void Widget::showColor()

{

        QColor qc=QColorDialog::getColor(QColor("#0023ff"),this,"dfsd");

        if(qc.isValid())

        {

        QPalette temp=this->palette();

        temp.setColor(QPalette::Background,qc);

            this->setPalette(temp);

        }

}

Widget::~Widget()

{

}

#include "widget.h"

#include <QApplication>

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    Widget w;

    w.show();

    return a.exec();

}