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：

 1 #ifndef SHOWPIXELDATA_H
 2 #define SHOWPIXELDATA_H
 3
 4 #include <QDialog>
 5 #include <QStandardItemModel>
 6 #include "hyperprocess.h"
 7
 8 class HyperProcess;
 9
10 namespace Ui {
11 class ShowPixelData;
12 }
13
14 class ShowPixelData : public QDialog
15 {
16     Q_OBJECT
17
18 public:
19     ShowPixelData(QWidget *parent = 0);
20     ~ShowPixelData();
21
22
23 private slots:
24     void receiveHyperToPixelDataSlot();  // 接受鼠标单击信号
25     void exitShowPixelDataSlot();  //
26
27 signals:
28     void sendExit();  //
29
30 private:
31     Ui::ShowPixelData *ui;
32     HyperProcess *ptr;
33
34     QStandardItemModel *myPixelData;
35
36     int currentRow;  // 行
37     int currentCol;  // 列
38     QString curFileName;  //  文件名
39 };
40
41 #endif // SHOWPIXELDATA_H

源文件如下：

 1 #include "ShowPixelData.h"
 2 #include "ui_ShowPixelData.h"
 3
 4
 5 ShowPixelData::ShowPixelData(QWidget *parent) :
 6     QDialog(parent),
 7     ui(new Ui::ShowPixelData)
 8 {
 9     ui->setupUi(this);
10
11     currentRow = -1;
12     currentCol = -1;
13     curFileName = "";
14     ptr = (HyperProcess*)parentWidget();   //获得主窗体的指针
15
16     ui->pixelInfo->setText("Pixel Info");
17     myPixelData = new QStandardItemModel;
18     myPixelData->setColumnCount(2);
19     myPixelData->setHorizontalHeaderLabels(QStringList()<<QStringLiteral("Band")<<QStringLiteral("Data"));
20     ui->pixelDataView->setModel(myPixelData);// 初始化
21     ui->pixelDataView->setEditTriggers(QAbstractItemView::NoEditTriggers);
22     ui->pixelDataView->setColumnWidth(0,75);
23     ui->pixelDataView->setColumnWidth(1,80);
24
25     connect(ptr,SIGNAL(sendSignalToShowPixelData()),this,SLOT(receiveHyperToPixelDataSlot()));
26     connect(ui->ExitButton,SIGNAL(clicked()),this,SLOT(exitShowPixelDataSlot()));
27 }
28
29 ShowPixelData::~ShowPixelData()
30 {
31     delete ui;
32 }
33
34 void ShowPixelData::receiveHyperToPixelDataSlot()
35 {
36     curFileName = ptr->curFileName;
37     currentRow = ptr->curRow;
38     currentCol = ptr->curCol;
39
40     if(curFileName == "")
41     {
42         QMessageBox::information(this,"Message Error","Current Scene IS NULL!");
43         return;
44     }
45
46     if(currentCol == -1 || currentRow == -1)
47     {
48         QMessageBox::information(this,"Message Error","please Select A Pixel");
49         return;
50     }
51
52     cv::Mat curImg = GDALOpenCV::GDAL2Mat(curFileName);
53     if(currentCol > curImg.cols || currentRow > curImg.rows)
54         return;
55
56     int count  = curImg.channels();
57     ui->pixelInfo->setText(QString("pixel:(%1,%2)").arg(currentRow+1).arg(currentCol+1));
58
59     std::vector<cv::Mat> curImgMat(count);
60     cv::split(curImg,curImgMat);
61     QVector<float> pixSpectralData(count);
62
63     myPixelData->clear();
64     myPixelData->setColumnCount(2);
65     myPixelData->setHorizontalHeaderLabels(QStringList()<<QStringLiteral("Band")<<QStringLiteral("Data"));
66     ui->pixelDataView->setModel(myPixelData);
67     ui->pixelDataView->setEditTriggers(QAbstractItemView::NoEditTriggers);
68     ui->pixelDataView->setColumnWidth(0,75);
69     ui->pixelDataView->setColumnWidth(1,75);
70     for(int c = 0;c<count;c++)
71     {
72         pixSpectralData[c] = curImgMat[c].at<float>(currentCol,currentRow);
73         myPixelData->setItem(c,0,new QStandardItem(tr("band%1").arg(QString::number(c+1, 10))));
74         myPixelData->setItem(c,1,new QStandardItem(QString("%1").arg(pixSpectralData[c])));
75     }
76     ui->pixelDataView->setModel(myPixelData);
77
78 }
79
80 void ShowPixelData::exitShowPixelDataSlot()
81 {
82     emit sendExit();
83     close();
84 }

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：

 1 private slots:
 2     void ShowPixelDataSlot();   // 显示子窗体槽
 3     void receiveRowColSlot(int,int);  // 从主窗体的GraphicsView接收行、列号，并传出信号
 4
 5 signals:
 6     void sendSignalToShowPixelData();
 7
 8 public:
 9     int curRow;
10     int curCol;
11     QString curFileName;

源文件：

 1 void HyperProcess::ShowPixelDataSlot()
 2 {
 3     if(currentSceneIndex == -1)
 4     {
 5         QMessageBox::information(this,"Message Error","please Open At Least One Image!");
 6         return;
 7     }else
 8     {
 9         myShowPixelData = new ShowPixelData(this);
10         myShowPixelData->show();
11         connect(myShowPixelData,SIGNAL(sendExit()),this,SLOT(receiveShowPixelDataSlot()));
12         myImg->setCursor(Qt::CrossCursor);
13         return;
14     }
15 }
16
17 void HyperProcess::receiveRowColSlot(int row,int col)
18 {
19     curCol = col;
20     curRow = row;
21     emit sendSignalToShowPixelData();
22 }
23
24 void HyperProcess::receiveShowPixelDataSlot()
25 {
26     myImg->setCursor(Qt::ArrowCursor);
27 }

三、实现效果