qt4 - 单个 QGraphicsScene 的多个 QGraphicsView

Question

我有一个 QGraphicsScene我添加了一些 QGraphicsItem 的实例.

我需要在单个 View 中显示整个场景的特定部分。

为此，我想创建 QGraphicsView 的多个实例。每个都显示我的 QGraphicsScene 的特定部分(不是类似的部分)。

怎么做到呢？

QGraphicsScene mcpGraphicsScene = new QGraphicsScene(this);

QGraphicsRectItem * mcpGraphicsRect = mcpGraphicsScene->addRect(5,5,200,200);

QGraphicsLineItem * mcpGraphicsLine = mcpGraphicsScene->addLine(500,500,300,300);


QGraphicsView * mcpGraphicsView1 = new QGraphicsView(this);
mcpGraphicsView1->setScene(mcpGraphicsScene);
mcpGraphicsView1->setGeometry(260,20,311,500);

QGraphicsView * mcpGraphicsView2 = new QGraphicsView(this);
mcpGraphicsView2->setScene(mcpGraphicsScene);
mcpGraphicsView2->setGeometry(260,520,311,1061);

Answer 1

您使用了错误的函数，您使用的是 setGeometry，它告诉 View 应该相对于其父级(即小部件，而不是场景)放置它的位置。要定义 View 负责显示的场景区域，您需要调用 use setSceneRect

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QGraphicsScene>
#include <QGraphicsView>
#include <QLayout>

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

    QHBoxLayout* myLayout = new QHBoxLayout(this);
    QGraphicsScene* mcpGraphicsScene = new QGraphicsScene(this);

    mcpGraphicsScene->addRect(5,5,200,200);
    mcpGraphicsScene->addLine(500,500,300,300);

    QGraphicsView * mcpGraphicsView1 = new QGraphicsView(mcpGraphicsScene, this);
    mcpGraphicsView1->setSceneRect(0,0,150,150);

    QGraphicsView * mcpGraphicsView2 = new QGraphicsView(mcpGraphicsScene, this);
    mcpGraphicsView2->setSceneRect(0,150,600,600);

    myLayout->addWidget(mcpGraphicsView1);
    myLayout->addWidget(mcpGraphicsView2);
    QWidget *window = new QWidget();
    window->setLayout(myLayout);
    setCentralWidget(window);
}

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