3. QT窗体间值的传递（续）

一、前言

上篇博客中通过重载子窗体的构造函数将主窗体的值传入到子窗体，但是在子窗体运行过程中如何才能将值动态的传入到子窗体？可以有两种办法，1、信号和槽的方式传值；2、主窗体中将传出值设置为public

本文主要实现功能为：鼠标点击主窗体的GraphicsView中的Scene时，将对应像素处的各个波段值传递给子窗体的TabelView并显示。其中子窗体的接受主窗体的值是通过2（public）的方式，简单方便。

二、主、子窗体的设计

定义子窗体类：ShowPixelData

主要实现：1 接受主窗体传入的文件名、当前点击图像的行、列号；

              2 根据传入值，读取并显示pixel data;

头文件如下：

#ifndef SHOWPIXELDATA_H
#define SHOWPIXELDATA_H

#include <QDialog>
#include <QStandardItemModel>
#include "hyperprocess.h"

class HyperProcess;

namespace Ui {
class ShowPixelData;
}

class ShowPixelData : public QDialog
{
    Q_OBJECT

public:
    ShowPixelData(QWidget *parent = 0);
    ~ShowPixelData();


private slots:
    void receiveHyperToPixelDataSlot();  // 接受鼠标单击信号
    void exitShowPixelDataSlot();  //

signals:
    void sendExit();  //

private:
    Ui::ShowPixelData *ui;
    HyperProcess *ptr;

    QStandardItemModel *myPixelData;

    int currentRow;  // 行
    int currentCol;  // 列
    QString curFileName;  //  文件名
};

#endif // SHOWPIXELDATA_H

源文件如下：

#include "ShowPixelData.h"
#include "ui_ShowPixelData.h"


ShowPixelData::ShowPixelData(QWidget *parent) :
    QDialog(parent),
    ui(new Ui::ShowPixelData)
{
    ui->setupUi(this);

    currentRow = -1;
    currentCol = -1;
    curFileName = "";
    ptr = (HyperProcess*)parentWidget();   //获得主窗体的指针

    ui->pixelInfo->setText("Pixel Info");
    myPixelData = new QStandardItemModel;
    myPixelData->setColumnCount(2);
    myPixelData->setHorizontalHeaderLabels(QStringList()<<QStringLiteral("Band")<<QStringLiteral("Data"));
    ui->pixelDataView->setModel(myPixelData);// 初始化
    ui->pixelDataView->setEditTriggers(QAbstractItemView::NoEditTriggers);
    ui->pixelDataView->setColumnWidth(0,75);
    ui->pixelDataView->setColumnWidth(1,80);

    connect(ptr,SIGNAL(sendSignalToShowPixelData()),this,SLOT(receiveHyperToPixelDataSlot()));
    connect(ui->ExitButton,SIGNAL(clicked()),this,SLOT(exitShowPixelDataSlot()));
}

ShowPixelData::~ShowPixelData()
{
    delete ui;
}

void ShowPixelData::receiveHyperToPixelDataSlot()
{
    curFileName = ptr->curFileName;
    currentRow = ptr->curRow;
    currentCol = ptr->curCol;

    if(curFileName == "")
    {
        QMessageBox::information(this,"Message Error","Current Scene IS NULL!");
        return;
    }

    if(currentCol == -1 || currentRow == -1)
    {
        QMessageBox::information(this,"Message Error","please Select A Pixel");
        return;
    }

    cv::Mat curImg = GDALOpenCV::GDAL2Mat(curFileName);
    if(currentCol > curImg.cols || currentRow > curImg.rows)
        return;

    int count  = curImg.channels();
    ui->pixelInfo->setText(QString("pixel:(%1,%2)").arg(currentRow+1).arg(currentCol+1));

    std::vector<cv::Mat> curImgMat(count);
    cv::split(curImg,curImgMat);
    QVector<float> pixSpectralData(count);

    myPixelData->clear();
    myPixelData->setColumnCount(2);
    myPixelData->setHorizontalHeaderLabels(QStringList()<<QStringLiteral("Band")<<QStringLiteral("Data"));
    ui->pixelDataView->setModel(myPixelData);
    ui->pixelDataView->setEditTriggers(QAbstractItemView::NoEditTriggers);
    ui->pixelDataView->setColumnWidth(0,75);
    ui->pixelDataView->setColumnWidth(1,75);
    for(int c = 0;c<count;c++)
    {
        pixSpectralData[c] = curImgMat[c].at<float>(currentCol,currentRow);
        myPixelData->setItem(c,0,new QStandardItem(tr("band%1").arg(QString::number(c+1, 10))));
        myPixelData->setItem(c,1,new QStandardItem(QString("%1").arg(pixSpectralData[c])));
    }
    ui->pixelDataView->setModel(myPixelData);

}

void ShowPixelData::exitShowPixelDataSlot()
{
    emit sendExit();
    close();
}

主窗体类：HyperProcess

实现功能：1 传出鼠标点击信号；

              2 public声明，并且动态改变相应的输出值

头文件如下：

private slots:
    void ShowPixelDataSlot();   // 显示子窗体槽
    void receiveRowColSlot(int,int);  // 从主窗体的GraphicsView接收行、列号，并传出信号

signals:
    void sendSignalToShowPixelData();

public:
    int curRow;
    int curCol;
    QString curFileName;

源文件：

void HyperProcess::ShowPixelDataSlot()
{
    if(currentSceneIndex == -1)
    {
        QMessageBox::information(this,"Message Error","please Open At Least One Image!");
        return;
    }else
    {
        myShowPixelData = new ShowPixelData(this);
        myShowPixelData->show();
        connect(myShowPixelData,SIGNAL(sendExit()),this,SLOT(receiveShowPixelDataSlot()));
        myImg->setCursor(Qt::CrossCursor);
        return;
    }
}

void HyperProcess::receiveRowColSlot(int row,int col)
{
    curCol = col;
    curRow = row;
    emit sendSignalToShowPixelData();
}

void HyperProcess::receiveShowPixelDataSlot()
{
    myImg->setCursor(Qt::ArrowCursor);
}

三、实现效果