QGIS二次开发：显示本地地图

库

直接安装

1	`sudo apt install libqgis-dev`

工程

按照标准流程创建一个MainWindow工程

在pro配置中修改

QT += xml # 这个是qgis库的依赖
# 头文件和库文件
INCLUDEPATH += /usr/include/qgis/

LIBS += -lqgis_core -lqgis_gui

代码

mainwindow.h

添加头文件

#include <QMainWindow>
#include <QFileDialog>
#include <QMessageBox>

#include "qgsmapcanvas.h"
#include "qgsvectorlayer.h"

添加成员变量

private:
    QgsMapCanvas *mapCanvas;

    QList<QgsMapLayer *> layers;

mainwindow.cpp

在构造函数里面创建画布

mapCanvas = new QgsMapCanvas();
this->setCentralWidget(mapCanvas);

mapCanvas->setCanvasColor(QColor(255, 255, 255));
mapCanvas->setVisible(true);
mapCanvas->enableAntiAliasing(true);

在ui中添加一个打开菜单

在对应槽函数里面添加打开shp文件功能

QString fileName = QFileDialog::getOpenFileName(this, tr("Open shape file"), "", "*.shp");
QStringList temp = fileName.split('/');
QString basename = temp.at(temp.size() - 1);
QgsVectorLayer* vecLayer = new QgsVectorLayer(fileName, basename, "ogr");

if (!vecLayer->isValid())
{
    QMessageBox::critical(this, "error", QString("layer is invalid: \n") + fileName);
    return;
}

mapCanvas->setExtent(vecLayer->extent());
layers.append(vecLayer);
mapCanvas->setLayers(layers);
mapCanvas->refresh();