我在QLineEdit
上有特定的字符串,该字符串通过QListView
传递到QPushButton
。这些字符串是QComboBox
的选择,它们非常具体:
1)“ [信息]最小距离:5”,
2)“ [信息]最小距离:10”和
3)“ [信息]最小距离:15”
[Here,如果需要测试,是一个可以正常工作的最小可验证示例。
当前,我可以successfully更改QGraphicsView
的颜色,但是通过单击或双击在QString
中输入的QListView
。
问题:如何更改QString
中特定的QListView
内容以更改QGraphicsView
的背景颜色?我的意思是我不想单击或双击QListView
的条目,但是我希望QListView
看到有一个字符串“ [INFO] Minimum Distance:5”,因此更改了自动更改QGraphicsView
的颜色,而无需单击或双击QListView
条目。在我“转到插槽”之后,我的选择如下:
在MVE工作代码下面,您可以在计算机上复制/粘贴,它将起作用:
mainwindow.h
#include <QMainWindow>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QGraphicsTextItem>
#include <QStringListModel>
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
void changeColorDetection();
void updateListView();
void updateListView(const QString & message);
private slots:
void on_pushButton_clicked();
void on_listView_entered(const QModelIndex &index);
void on_listView_activated(const QModelIndex &index);
private:
Ui::MainWindow *ui;
QGraphicsView *mView;
QGraphicsScene *mScene;
QGraphicsTextItem *mText;
StringList *newString;
QStringListModel *model;
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
mView = new QGraphicsView();
mScene = new QGraphicsScene();
ui->graphicsView->setScene(mScene);
QFont font;
font.setPixelSize(10);
font.setBold(false);
font.setFamily("Calibri");
mText = new QGraphicsTextItem;
mText->setPos(150,70);
mScene->addText(tr("Boat outside alarm area"))->setDefaultTextColor(Qt::black);
model = new QStringListModel();
ui->listView->setModel(model);
ui->listView->setEditTriggers(QAbstractItemView::NoEditTriggers);
emptyIndex();
connect(ui->listView, SIGNAL(loggingUpdated()), this, SLOT(updateListView(const QString &)));
connect(ui->graphicsView, SIGNAL(clicked(const QModelIndex &)), this, SLOT(on_listView_activated(const QModelIndex &index)));
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::updateListView(const QString & message)
{
if(model->insertRow(model->rowCount())) {
QModelIndex index = model->index(model->rowCount() - 1, 0);
model->setData(index, message);
ui->listView->scrollTo(index);
}
}
void MainWindow::on_pushButton_clicked()
{
QString str = ui->lineEdit->text();
model->insertRow(model->rowCount());
QModelIndex index = model->index(model->rowCount()-1);
model->setData(index, str);
ui->listView->scrollToBottom();
}
void MainWindow::on_comboBox_currentIndexChanged(const QString &arg1)
{
QString list = ui->comboBox->currentText();
ui->lineEdit->setText(list);
Q_UNUSED(arg1)
}
void MainWindow::on_listView_activated(const QModelIndex &index)
{
QStringList allStrings = model->stringList();
QString last = allStrings.last();
if(last.startsWith("[ INFO] Minimum Distance: 5"))
{
ui->graphicsView->setBackgroundBrush(QColor(Qt::red));
}
else if(last.startsWith("[ INFO] Minimum Distance: 10"))
{
ui->graphicsView->setBackgroundBrush(QColor(Qt::yellow));
}
else if(last.startsWith("[ INFO] Minimum Distance: 15"))
{
ui->graphicsView->setBackgroundBrush(QColor(Qt::green));
}
Q_UNUSED(index)
}
编辑2
mainwindow.h
#include <QMainWindow>
#include <QGraphicsView>
#include <QGraphicsScene>
#include <QGraphicsTextItem>
#include <QStringListModel>
#include "listview.h"
QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = nullptr);
~MainWindow();
public slots:
void setGraphicViewColor(QColor c);
private:
Ui::MainWindow *ui;
QGraphicsView *mView;
QGraphicsScene *mScene;
QGraphicsTextItem *mText;
QStringListModel *model;
ListView *myListView;
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);
mView = new QGraphicsView();
mScene = new QGraphicsScene();
ui->graphicsView->setScene(mScene);
QFont font;
font.setPixelSize(10);
font.setBold(false);
font.setFamily("Calibri");
mText = new QGraphicsTextItem;
mText->setPos(150,70);
mScene->addText(tr("Boat outside alarm area"))->setDefaultTextColor(Qt::black);
model = new QStringListModel();
ui->listView->setModel(model);
ui->listView->setEditTriggers(QAbstractItemView::NoEditTriggers);
connect(ui->listView, SIGNAL(changeColor(QColor)), this, SLOT(setGraphicViewColor(QColor)));
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::setGraphicViewColor(QColor c)
{
qDebug() << "Update your graphicsView backgroundBrush" << c;
ui->graphicsView->setBackgroundBrush(Qt::green);
}
listview.h
#ifndef LISTVIEW_H
#define LISTVIEW_H
#include <QListView>
#include <QStringListModel>
class ListView : public QListView
{
Q_OBJECT
public:
ListView(QWidget *parent = nullptr);
signals:
void changeColor(QColor c);
protected:
void dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles = QVector<int>()) override;
};
#endif // LISTVIEW_H
listview.cpp
#include "listview.h"
ListView::ListView(QWidget *parent)
: QListView(parent)
{}
void ListView::dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector<int> &roles)
{
QListView::dataChanged(topLeft, bottomRight, roles);
/**
* Assuming that you have just one item changed
* So topLeft == bottomRight
*/
if (topLeft.row() == model()->rowCount()-1){
QString last = topLeft.data().toString();
if(last.startsWith("[ INFO] Minimum Distance: 5")) {
emit changeColor(Qt::red);
} else if(last.startsWith("[ INFO] Minimum Distance: 10")) {
emit changeColor(Qt::yellow);
} else if(last.startsWith("[ INFO] Minimum Distance: 15")) {
emit changeColor(Qt::green);
}
}
}
到目前为止我所做的:
我在这个问题上进行了很多研究,发现this source很有用,但不能解决问题,但除此之外,似乎使用了QModelIndex
,我不确定这正是我所要解决的问题。需要这个小项目。我也阅读了this source,它对于建立和捕获特定且唯一的字符串很有用,但是就改变颜色而言,我无法解决。
非常感谢您为解决此问题指明了正确的方向。
我在QLineEdit上有一个特定的字符串,该字符串通过QPushButton传递给QListView。这些字符串是QComboBox的选择,它们非常具体:1)“ [INFO]最小距离:5”,...
backgroundBrush
的最后一项以您的特定字符串开头,则您想更改graphicsView
的QStringListModel
。