C++11 lambda

MergePointDialog.h

#ifndef MERGEPOINTDIALOG_H
#define MERGEPOINTDIALOG_H

#include <QDialog>
#include <functional>
using namespace std;
typedef std::function<void(QString)> Complete;


namespace Ui {
class MergePointDialog;
}

class MergePointDialog : public QDialog
{
    Q_OBJECT

public:
    explicit MergePointDialog(QWidget *parent = 0);
    ~MergePointDialog();
    void setOnCompleteListener(Complete complete);

private slots:
    void on_btnConfirm_clicked();

    void on_btnCancel_clicked();

private:
    Ui::MergePointDialog *ui;
    Complete mComplete=NULL;
};

#endif // MERGEPOINTDIALOG_H

MergePointDialog.c

#include "MergePointDialog.h"
#include "ui_MergePointDialog.h"
#include <QDoubleValidator>
MergePointDialog::MergePointDialog(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::MergePointDialog)
{
    ui->setupUi(this);
}

MergePointDialog::~MergePointDialog()
{
    delete ui;
}
void MergePointDialog::setOnCompleteListener(Complete complete){
    this->mComplete=complete;
}

void MergePointDialog::on_btnConfirm_clicked(){
    if(this->mComplete!=NULL){
        this->mComplete(ui->leValue->text());
    }
    this->close();
}

void MergePointDialog::on_btnCancel_clicked(){
    this->close();
}

MergePointDialog *dialog=new MergePointDialog;
    dialog->setOnCompleteListener([=](QString value){
        qDebug()<<"========";
        //        ProjectUtil::mergePoint(value);
       this->drawPointLine(Constant::SCREEN_SEG_LIST);
    });
    dialog->show();