添加文本在GraphicsView在Qt
Adding Text in GraphicsView in Qt
我正在实现一个代码来添加一个按钮单击不同的实体。我得到一个问题，在图形视图中添加文本。以下是我正在实现的代码片段。需要做些什么?mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QPaintEvent>
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QPainter>
#include "line.h"
#include "circle.h"
#include "ellipse.h"
#include "point.h"
#include "arc.h"
#include "text.h"
namespace Ui {
class MainWindow;
}
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
protected:
void wheelEvent(QWheelEvent* event);
private:
Ui::MainWindow *ui;
bool mFirstClick;
bool mPaintFlag;
int mStartX;
int mStartY;
int mEndX;
int mEndY;
QGraphicsScene *scene;
QPainter *painter;
point *item;
line *item1;
circle *item2;
ellipse *item3;
arc *item4;
private slots:
void drawPoint();
void drawLine();
void drawCircle();
void drawEllipse();
void drawArc();
void drawText();
void on_actionSave_triggered();
void on_actionOpen_triggered();
void on_actionQuit_2_triggered();
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QMouseEvent>
#include<QFileDialog>
#include<QMessageBox>
#include<QTextEdit>
#include<QString>
#include <QDebug>
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent), ui(new Ui::MainWindow)
{
ui->setupUi(this);
setWindowTitle(tr("GD CAD"));
scene = new QGraphicsScene;
for(int x = 0; x <= ui->graphicsView->width(); x += 10){
scene->addLine(x,0,x,ui->graphicsView->height(),QPen(Qt::green));
}
for(int y = 0; y <= ui->graphicsView->height(); y += 10){
scene->addLine(0,y,ui->graphicsView->width(),y,QPen(Qt::green));
}
for(int x = 10; x <= ui->graphicsView->width(); x += 100){
scene->addLine(x,0,x,ui->graphicsView->height(),QPen(Qt::darkGreen));
}
for(int y = 10; y <= ui->graphicsView->height(); y += 100){
scene->addLine(0,y,ui->graphicsView->width(),y,QPen(Qt::darkGreen));
}
ui->graphicsView->setScene(scene);
connect(ui->pointButton, SIGNAL(clicked()), this, SLOT(drawPoint()));
connect(ui->lineButton, SIGNAL(clicked()), this, SLOT(drawLine()));
connect(ui->circleButton, SIGNAL(clicked()), this, SLOT(drawCircle()));
connect(ui->ellipseButton, SIGNAL(clicked()), this, SLOT(drawEllipse()));
connect(ui->arcButton, SIGNAL(clicked()),this, SLOT(drawArc()));
connect(ui->text,SIGNAL(clicked()),this,SLOT(drawText()));
connect(ui->actionPoints, SIGNAL(triggered()), this, SLOT(drawPoint()));
connect(ui->actionLine, SIGNAL(triggered()), this, SLOT(drawLine()));
connect(ui->actionCircle, SIGNAL(triggered()), this, SLOT(drawCircle()));
connect(ui->actionEllipse, SIGNAL(triggered()), this, SLOT(drawEllipse()));
}
void MainWindow::drawPoint(){
ui->graphicsView->setScene(scene);
item = new point;
scene->addItem(item);
qDebug() << "Point Created";
connect(item, SIGNAL(DrawFinished()), this, SLOT(drawPoint()));
}
void MainWindow::drawLine(){
ui->graphicsView->setScene(scene);
item1 = new line;
scene->addItem(item1);
qDebug() << "Line Created";
connect(item1, SIGNAL(DrawFinished()), this, SLOT(drawLine()));
}
void MainWindow::drawCircle(){
ui->graphicsView->setScene(scene);
item2 = new circle;
scene->addItem(item2);
qDebug() << "Circle Created";
connect(item2, SIGNAL(DrawFinished()), this, SLOT(drawCircle()));
}
void MainWindow::drawArc(){
ui->graphicsView->setScene(scene);
item4 = new arc;
scene->addItem(item4);
qDebug() << "Circle Created";
connect(item4, SIGNAL(DrawFinished()), this, SLOT(drawArc()));
}
void MainWindow::drawEllipse(){
ui->graphicsView->setScene(scene);
item3 = new ellipse;
scene->addItem(item3);
qDebug() << "Ellipse Created";
connect(item3, SIGNAL(DrawFinished()), this, SLOT(drawEllipse()));
}
void MainWindow::wheelEvent(QWheelEvent* event) {
ui->graphicsView->setTransformationAnchor(QGraphicsView::AnchorUnderMouse);
// Scale the view / do the zoom
double scaleFactor = 1.15;
if(event->delta() > 0) {
// Zoom in
ui->graphicsView->scale(scaleFactor, scaleFactor);
} else {
// Zooming out
ui->graphicsView->scale(1.0 / scaleFactor, 1.0 / scaleFactor);
}
}
void MainWindow::on_actionOpen_triggered()
{
QString filename=QFileDialog::getOpenFileName(
this,
tr("Open File"),
QString(),
tr("file Name(*.dwg|*.DWG|*.dxf)")
);
if (!filename.isEmpty()) {
QFile file(filename);
if (!file.open(QIODevice::ReadOnly)) {
QMessageBox::critical(this,
tr("Error"), tr("Could not open file"));
return;
}
}
}
void MainWindow::on_actionSave_triggered()
{
QString filename=QFileDialog::getSaveFileName(
this,
tr("Save File"),
QString(),
tr("file Name(*.txt)")
);
if(!filename.isEmpty()) {
QFile file(filename);
if (!file.open(QIODevice::WriteOnly)) {
QMessageBox::critical(this, tr("Error"), tr("Could not open file"));
return;
} else {
QTextStream stream(&file);
QTextEdit *textEdit;
stream << textEdit->toPlainText();
stream.flush();
file.close();
}
}
}
void MainWindow::on_actionQuit_2_triggered(){
MainWindow *window;
window->close();
}
void MainWindow::drawText(){
ui->graphicsView->setScene(scene);
text *item5 = new text;
scene->addItem(item5);
qDebug() << "text created";
connect(item5, SIGNAL(DrawFinished()), this, SLOT(drawText()));
}
MainWindow::~MainWindow()
{
delete ui;
}
text.h
#ifndef TEXT_H
#define TEXT_H
#include <QGraphicsTextItem>
#include <QPen>
#include<QFocusEvent>
#include<QGraphicsItem>
#include<QGraphicsScene>
#include<QGraphicsSceneMouseEvent>
#include<QGraphicsTextItem>
#include<QFont>
#include"mainwindow.h"
#include"ui_mainwindow.h"
class text:public QGraphicsTextItem
{
Q_OBJECT
public:
enum { Type = UserType + 3 };
enum Mode { InsertText };
void setFont(const QFont &font);
text(QGraphicsItem *parent = 0);
int type() const { return Type; }
public slots:
void setMode(Mode mode);
signals:
void lostFocus(text *item);
void selectedChange(QGraphicsItem *item);
void textInserted(QGraphicsTextItem *item);
void itemSelected(QGraphicsItem *item);
protected:
QVariant itemChange(GraphicsItemChange change, const QVariant &value);
void focusOutEvent(QFocusEvent *event);
void mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event);
void mousePressEvent(QGraphicsSceneMouseEvent *mouseEvent);
private:
Mode myMode;
QFont myFont;};
#endif // TEXT_H
text.cpp
#include "text.h"
#include"mainwindow.h"
#include"ui_mainwindow.h"
text::text(QGraphicsItem *parent):QGraphicsTextItem(parent)
{
setFlag(QGraphicsItem::ItemIsMovable);
setFlag(QGraphicsItem::ItemIsSelectable);
}
QVariant text::itemChange(GraphicsItemChange change,
const QVariant &value)
{
if (change == QGraphicsItem::ItemSelectedHasChanged)
emit selectedChange(this);
return value;
}
void text::focusOutEvent(QFocusEvent *event)
{
setTextInteractionFlags(Qt::NoTextInteraction);
emit lostFocus(this);
QGraphicsTextItem::focusOutEvent(event);
}
void text::setMode(Mode mode)
{
myMode = mode;
}
void text::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
{
if (textInteractionFlags() == Qt::NoTextInteraction)
setTextInteractionFlags(Qt::TextEditorInteraction);
QGraphicsTextItem::mouseDoubleClickEvent(event);
}
void text::mousePressEvent(QGraphicsSceneMouseEvent *mouseEvent)
{
if (mouseEvent->button() != Qt::LeftButton)
return;
switch(myMode){
case InsertText:
text *textItem;
textItem = new text();
// textItem->setFont(myFont);
textItem->setPlainText("hello");
textItem->setTextInteractionFlags(Qt::TextEditorInteraction);
textItem->setZValue(1000.0);
connect(textItem, SIGNAL(lostFocus(DiagramTextItem*)),
this, SLOT(editorLostFocus(DiagramTextItem*)));
connect(textItem, SIGNAL(selectedChange(QGraphicsItem*)),
this, SIGNAL(itemSelected(QGraphicsItem*)));
//addItem(textItem);
// textItem->setDefaultTextColor(myTextColor);
textItem->setPos(mouseEvent->scenePos());
emit textInserted(textItem);
//! [8] //! [9]
default:
;
}
// QGraphicsScene::mousePressEvent(mouseEvent);
}
嗯，如果我没弄错的话，看起来你确实在设置文本项的各种属性，比如交互标志、z值、颜色等等——除了实际的文本之外的所有属性。文本将是空的，因此您的QGraphicsTextItem将是不可见的。在文本项上使用set明文()，sethhtml()或setDocument()。有两个地方可以创建文本项;一个在主窗口中。cpp:
void MainWindow::drawText(){
ui->graphicsView->setScene(scene);
text *item5 = new text;
scene->addItem(item5);
qDebug() << "text created";
connect(item5, SIGNAL(DrawFinished()), this, SLOT(drawText()));
}
文本被创建并添加到场景中(使用addItem())，但它没有实际的内容;设置其内容:
item5->setPlainText ("Mickey");
第二个文本项是从文本(它是QGraphicsTextItem的子类)类本身内部创建的:
void text::mousePressEvent(QGraphicsSceneMouseEvent *mouseEvent)
{
...
switch(myMode){
case InsertText:
text *textItem;
textItem = new text();
// textItem->setFont(myFont);
textItem->setPlainText("hello");
它被正确创建，并给出一个文本，但没有添加到场景中。将其添加到场景中，例如将其设置为当前文本项的子元素:
textItem->setParentItem (this);
相关文章：
- Qt VTK交互风格的信号到小部件
- QT在错误的班级中寻找空位
- 如何在选项卡视图Qt中设置一个新项目，并保存以前的项目
- 如何在Qt窗口小部件中使用QStringView(或QStringRef）
- 如何在Qt C++中更改光标
- 如何在MS Visual Studio 2019中运行QT UI
- QT通过C++添加映射QML项目
- libssh 的函数在构建 libssh 时无法在 Qt 和 cmake 错误中找到
- 如何将点击的信号和插槽添加到qt中的自定义按钮中
- Qt C++静态thread_local QNetworkAccessManager是线程应用程序的好选择吗
- 使用Qt C++计算类似Git的SHA1哈希
- Qt focusObjectChanged example?
- 如何在cpp文件之间切换窗口?在Qt中
- Qt和C++:将QLineEdit添加到QTabWidget中
- 从数据库实时显示QT c++中的数据
- Qt Quick-如何仅从c++代码与qml属性交互
- 无法使用Qt Creator在Windows中构建yaml-cpp
- 如何在Qt中取消捕获字符串
- Qt GraphicsView mouseMoveEvent shadowing GraphicsItem mouseM
- 添加文本在GraphicsView在Qt
