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

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

     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 == - || currentRow == -)
     {
         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+).arg(currentCol+));

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

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