1.簡(jiǎn)介
QgsMapTool地圖工具是用于操作地圖畫(huà)布的用戶交互式工具。例如，地圖平移和縮放功能被實(shí)現(xiàn)為地圖工具。
QgsMapTool是抽象基類，以下是類的繼承關(guān)系：
- QgsMapToolEdit：用于編輯矢量幾何圖形的映射工具的基類?
- QgsMapToolEmitPoint：一個(gè)地圖工具，當(dāng)單擊地圖時(shí)，它只是發(fā)出一個(gè)點(diǎn)。
將一個(gè)槽連接到它的canvasClicked()信號(hào)將允許您為傳入點(diǎn)實(shí)現(xiàn)自定義行為。 - QgsMapToolExtent：地圖畫(huà)布上繪制矩形發(fā)出一個(gè)范圍。
- QgsMapToolIdentify ：用于識(shí)別圖層特征的映射工具。
- QgsMapToolPan：用于平移地圖的地圖工具。
- QgsMapToolZoom ：用于放大/縮小地圖的地圖工具。
2.常用接口
| virtual void canvasDoubleClickEvent (QgsMapMouseEvent *e) | 重寫(xiě)鼠標(biāo)雙擊事件 |
| virtual void?canvasMoveEvent (QgsMapMouseEvent *e) | 重寫(xiě)鼠標(biāo)移動(dòng)事件 |
| virtual void canvasPressEvent (QgsMapMouseEvent *e) | 重寫(xiě)鼠標(biāo)按下事件 |
| virtual void canvasReleaseEvent (QgsMapMouseEvent *e) | 重寫(xiě)鼠標(biāo)抬起事件 |
| virtual void?setCursor (const QCursor &cursor) | 設(shè)置光標(biāo) |
| QgsPointXY toMapCoordinates (QPoint point) | 將點(diǎn)從屏幕坐標(biāo)轉(zhuǎn)換為地圖坐標(biāo)。 |
3.示例?
示例1：畫(huà)布移動(dòng)、放大、縮小
源碼：
#pragma once
#include <QtWidgets/QMainWindow>
#include "ui_GisCtrl.h"
#include <QDebug>
#include <QFileInfo>
#include <qgsmaptoolpan.h>
#include <qgsrasterlayer.h>
#include <qgsmapcanvas.h>
#include <qgspoint.h>
#include <QMouseEvent>
#include <qgsmaptoolzoom.h>
#include <QActionGroup>
class GisCtrl : public QMainWindow
{
Q_OBJECT
public:
GisCtrl(QWidget *parent = Q_NULLPTR);
private:
Ui::GisCtrlClass ui;
private slots:
void slotXyCoordinates(const QgsPointXY &p);
void slotMove();
void slotZoomIn();
void slotZoomOut();
private:
QgsMapCanvas *m_mapCanvas = nullptr;
QList<QgsMapLayer *> m_layers;
QgsMapToolPan *m_toolPan = nullptr; // 新建移動(dòng)工具
QgsMapToolZoom *m_toolZoomIn = nullptr;//放大
QgsMapToolZoom *m_toolZoomOut = nullptr;//縮小
QActionGroup *m_actionGroup = nullptr;
};
#include "GisCtrl.h"
#include <qgsrasterlayer.h>
#include <qgsrubberband.h>
#pragma execution_character_set("utf-8")
GisCtrl::GisCtrl(QWidget *parent)
: QMainWindow(parent)
{
ui.setupUi(this);
//創(chuàng)建畫(huà)布
m_mapCanvas = new QgsMapCanvas(this);
QString url = "F:/arcgis/TMS.xml";
m_mapCanvas->setCanvasColor(QColor(255, 255, 255));
//加載瓦片地圖
QgsRasterLayer *layer = new QgsRasterLayer(url);
if (!layer->isValid())
{
qDebug() << "load map faild";
}
m_layers.append(layer);
// 新建移動(dòng)工具
m_toolPan = new QgsMapToolPan(m_mapCanvas);
m_mapCanvas->setExtent(layer->extent());
m_mapCanvas->enableAntiAliasing(true);
m_mapCanvas->setLayers(m_layers);
m_mapCanvas->setMapTool(m_toolPan);
m_toolZoomIn = new QgsMapToolZoom(m_mapCanvas, false);
m_toolZoomOut = new QgsMapToolZoom(m_mapCanvas, true);
m_actionGroup = new QActionGroup(this);
m_actionGroup->addAction(ui.actionMove);
m_actionGroup->addAction(ui.actionZoomIn);
m_actionGroup->addAction(ui.actionZoomOut);
m_actionGroup->setExclusive(true);
connect(m_mapCanvas, &QgsMapCanvas::xyCoordinates, this, &GisCtrl::slotXyCoordinates);
connect(ui.actionMove, &QAction::triggered, this, &GisCtrl::slotMove);
connect(ui.actionZoomIn, &QAction::triggered, this, &GisCtrl::slotZoomIn);
connect(ui.actionZoomOut, &QAction::triggered, this, &GisCtrl::slotZoomOut);
setCentralWidget(m_mapCanvas);
ui.actionMove->setChecked(true);
ui.actionLineManager->setVisible(false);
ui.actionLayer->setVisible(false);
ui.actionSelect->setVisible(false);
ui.actionItem->setVisible(false);
}
void GisCtrl::slotXyCoordinates(const QgsPointXY &p)
{
QString str = QString("經(jīng)度= %1，緯度=%2").arg(QString::number(p.x(), 'f', 6)).arg(QString::number(p.y(), 'f', 6));
this->statusBar()->showMessage(str);
}
void GisCtrl::slotMove()
{
m_mapCanvas->setMapTool(m_toolPan);
}
void GisCtrl::slotZoomIn()
{
m_mapCanvas->setMapTool(m_toolZoomIn);
}
void GisCtrl::slotZoomOut()
{
m_mapCanvas->setMapTool(m_toolZoomOut);
}
示例2：鼠標(biāo)點(diǎn)擊畫(huà)矩形。
自定義一個(gè)地圖交互工具繼承QgsMapToolIdentify
源碼：
#pragma once
#include <QObject>
#include <QList>
#include <QScopedPointer>
#include <qgsmapcanvas.h>
#include <qgsmaptoolidentify.h>
#include <qgsrubberband.h>
#include <qgsmapmouseevent.h>
class QgsMapToolSelectFeatures : public QgsMapToolIdentify
{
Q_OBJECT
public:
QgsMapToolSelectFeatures(QgsMapCanvas *mapCanvas);
protected:
//重寫(xiě)鼠標(biāo)移動(dòng)
void canvasMoveEvent(QgsMapMouseEvent *e) override;
//重寫(xiě)鼠標(biāo)按下
void canvasPressEvent(QgsMapMouseEvent *e) override;
void initRubberBand();
private:
// 是否正在選擇
bool mSelectionActive = false;
QScopedPointer<QgsRubberBand> mSelectionRubberBand;
QColor mFillColor = QColor(255, 255, 0, 63);
QColor mStrokeColor = QColor(255, 255, 0, 100);
QPoint mInitDragPos;
};
//cpp
#include "QgsMapToolSelectFeatures.h"
#include "QgsMapToolIdentify.h"
QgsMapToolSelectFeatures::QgsMapToolSelectFeatures(QgsMapCanvas *mapCanvas)
: QgsMapToolIdentify(mapCanvas)
{
}
void QgsMapToolSelectFeatures::canvasMoveEvent(QgsMapMouseEvent * e)
{
if (e->buttons() != Qt::LeftButton)
return;
QRect rect;
if (!mSelectionActive)
{
mSelectionActive = true;
rect = QRect(e->pos(), e->pos());
}
else
{
rect = QRect(e->pos(), mInitDragPos);
}
if (mSelectionRubberBand)
mSelectionRubberBand->setToCanvasRectangle(rect);
}
void QgsMapToolSelectFeatures::canvasPressEvent(QgsMapMouseEvent * e)
{
if (!mSelectionRubberBand)
initRubberBand();
mInitDragPos = e->pos();
}
void QgsMapToolSelectFeatures::initRubberBand()
{
mSelectionRubberBand.reset(new QgsRubberBand(mCanvas, QgsWkbTypes::PolygonGeometry));
mSelectionRubberBand->setFillColor(mFillColor);
mSelectionRubberBand->setStrokeColor(mStrokeColor);
}使用
QgsMapToolSelectFeatures *m_tool = new QgsMapToolSelectFeatures(m_mapCanvas);
m_mapCanvas->setMapTool(m_tool);示例3：右鍵彈出菜單標(biāo)注地點(diǎn)。
#pragma once
#include <QObject>
#include <QList>
#include <QScopedPointer>
#include <qmath.h>
#include <qgsmapcanvas.h>
#include <qgsmaptoolidentify.h>
#include <qgsrubberband.h>
#include <qgsmapmouseevent.h>
#include <qgsgeometry.h>
#include <QMenu>
class QgsRubberBand;
class QgsAnnotationPointTextItem;
class QgsMapToolAddItem : public QgsMapToolIdentify
{
Q_OBJECT
public:
QgsMapToolAddItem(QgsMapCanvas *mapCanvas);
typedef struct _mark
{
QgsRubberBand *rubberBand; //svg圖標(biāo)item
QgsGeometry geo; //區(qū)域
QgsAnnotationPointTextItem *text;//字體
QgsAnnotationLayer *layer;
}Mark;
protected:
//重寫(xiě)鼠標(biāo)按下
void canvasPressEvent(QgsMapMouseEvent *e) override;
private slots:
void slotAdd();
void slotDel();
void slotShowScale(double scale);
void slotZoomLastStatusChanged(bool);
private:
// 是否正在選擇
bool mSelectionActive = false;
QMenu *m_menu = nullptr;
QAction *m_add = nullptr;
QAction *m_del = nullptr;
QgsMapCanvas *m_canvas;
QList<Mark> m_lstMark;
};
#include "QgsMapToolAddItem.h"
#include "QgsMapToolIdentify.h"
#include "qgsapplication.h"
#include "qgsvectorlayer.h"
#include <QMessageBox>
#include <qgsfeature.h>
#include <qgsvectorlayer.h>
#include <qgsrectangle.h>
#include <QMouseEvent>
#include <QMessageBox>
#include "BaseFunc.h"
#include <qgsannotationlayer.h>
#include <qgsannotationpointtextitem.h>
#pragma execution_character_set("utf-8")
extern bool g_is3857crs;
extern QList<QgsMapLayer *> g_layers;
static QgsPointXY g_point;
static int g_index = -1;
QgsMapToolAddItem::QgsMapToolAddItem(QgsMapCanvas *mapCanvas)
: QgsMapToolIdentify(mapCanvas)
, m_canvas(mapCanvas)
{
this->setCursor(Qt::CrossCursor);
m_menu = new QMenu();
m_add = m_menu->addAction(QIcon(QPixmap(":/GisCtrl/image/add.png")),"添加");
m_del = m_menu->addAction(QIcon(QPixmap(":/GisCtrl/image/del.png")),"刪除");
connect(m_add, &QAction::triggered, this, &QgsMapToolAddItem::slotAdd);
connect(m_del, &QAction::triggered, this, &QgsMapToolAddItem::slotDel);
connect(mapCanvas, &QgsMapCanvas::zoomLastStatusChanged,
this, &QgsMapToolAddItem::slotZoomLastStatusChanged);
}
void QgsMapToolAddItem::canvasPressEvent(QgsMapMouseEvent * e)
{
if (e->buttons() == Qt::RightButton)
{
g_point = e->mapPoint();
bool isHaveItem = false;
const QgsMapToPixel *mtransform = m_canvas->getCoordinateTransform();
for (int i = 0; i < m_lstMark.size(); i++)
{
Mark item = m_lstMark.at(i);
QgsVector qgsVector;
QgsPointXY p2 = item.geo.asPoint();
QgsPointXY curPoint = mtransform->transform(g_point.x(), g_point.y());
QgsPointXY itemPoint = mtransform->transform(p2.x(), p2.y());
qgsVector = curPoint - itemPoint;
if ((-10 < qgsVector.x() && qgsVector.x() < 15) &&
(-10 < qgsVector.y() && qgsVector.y() < 15))
{
isHaveItem = true;
g_index = i;
break;
}
}
if (!isHaveItem)
g_index = -1;
QPoint point = e->pos();
point.setY(point.y() + 80);
m_del->setVisible(isHaveItem);
m_menu->exec(point);
}
else
{
m_menu->hide();
}
}
void QgsMapToolAddItem::slotAdd()
{
//添加點(diǎn)
QgsRubberBand *rb = new QgsRubberBand(m_canvas, QgsWkbTypes::PointGeometry);
//rb->setOpacity(0.8);
rb->setIcon(QgsRubberBand::IconType::ICON_SVG); //設(shè)置圖標(biāo)類型
rb->setIconSize(5); //設(shè)置圖標(biāo)尺寸
rb->setSvgIcon(":/GisCtrl/image/water.svg", QPoint(-16, -16)); //設(shè)置圖標(biāo)文件路徑和偏移
QgsGeometry geo = QgsGeometry::fromPointXY(g_point); //經(jīng)緯度
rb->addGeometry(geo); //繪制
//添加文字
QgsCoordinateTransformContext coordinateTransformContext;
//先構(gòu)造出一個(gè)能加注記的圖層
QgsAnnotationLayer *textLayer = new QgsAnnotationLayer("annotationLayer",
QgsAnnotationLayer::LayerOptions(coordinateTransformContext));
double lon = 0, lat = 0;
BaseFunc::WebMercatorToWGS84(g_point.x(), g_point.y(), &lon, &lat);
//構(gòu)造時(shí)傳入地理坐標(biāo)，有必要后期改成鼠標(biāo)事件點(diǎn)擊來(lái)創(chuàng)建QgsAnnotationMarkerItem
const QgsMapToPixel *mtransform = m_canvas->getCoordinateTransform();
//轉(zhuǎn)換到屏幕坐標(biāo)
QgsPointXY offsetPoint = mtransform->transform(g_point.x(), g_point.y());
int yOffset = 25;
offsetPoint.setY(offsetPoint.y() + yOffset);
//轉(zhuǎn)回去到地圖坐標(biāo)
offsetPoint = mtransform->toMapCoordinates(offsetPoint.x(), offsetPoint.y());
QString showText = QString("%1,%2").arg(QString::number(lon, 'f', 6)).arg(QString::number(lat, 'f', 6));
QgsAnnotationPointTextItem* textItem = new QgsAnnotationPointTextItem(showText, QgsPoint(offsetPoint.x(), offsetPoint.y()));
textItem->setAlignment(Qt::AlignHCenter);
QgsTextFormat format;
QFont font;
font.setBold(true);
font.setPointSize(13);
format.setFont(font);
format.setColor(QColor(Qt::yellow));
textItem->setFormat(format);
textLayer->addItem(textItem);//畫(huà)布添加Item
Mark mark;
mark.rubberBand = rb;
mark.geo = geo;
mark.text = textItem;
mark.layer = textLayer;
m_lstMark.append(mark);
g_layers.push_front(textLayer);
m_canvas->setLayers(g_layers);
m_canvas->refresh();
}
void QgsMapToolAddItem::slotDel()
{
if (g_index < 0)
return;
Mark mark = m_lstMark.at(g_index);
g_layers.removeOne(mark.layer);
delete mark.layer;
mark.rubberBand->reset();
delete mark.rubberBand;
m_lstMark.removeAt(g_index);
m_canvas->setLayers(g_layers);
m_canvas->refresh();
}
void QgsMapToolAddItem::slotShowScale(double scale)
{
qDebug() << "scale = " << scale;
}
void QgsMapToolAddItem::slotZoomLastStatusChanged(bool)
{
for (int i = 0; i < m_lstMark.size(); i++)
{
QgsPointXY xy = m_lstMark.at(i).geo.asPoint();
const QgsMapToPixel *mtransform = m_canvas->getCoordinateTransform();
//轉(zhuǎn)換到屏幕坐標(biāo)
QgsPointXY offsetPoint = mtransform->transform(xy.x(), xy.y());
int yOffset = 25;
offsetPoint.setY(offsetPoint.y() + yOffset);
//轉(zhuǎn)回去到地圖坐標(biāo)
offsetPoint = mtransform->toMapCoordinates(offsetPoint.x(), offsetPoint.y());
m_lstMark.at(i).text->setPoint(QgsPoint(offsetPoint.x(), offsetPoint.y()));
}
}
4.更多參考
Qgis二次開(kāi)發(fā)-QgsAnnotationItem（添加文字、圖片標(biāo)注（支持svg、png、jpg等常用圖片格式））_Mr.codeee的博客-CSDN博客
Qgis二次開(kāi)發(fā)-QgsMapCanvas畫(huà)布簡(jiǎn)介_(kāi)Mr.codeee的博客-CSDN博客?
Qgis二次開(kāi)發(fā)-QgsRubberBand詳解（畫(huà)線、畫(huà)多邊形）_Mr.codeee的博客-CSDN博客?文章來(lái)源：http://www.zghlxwxcb.cn/news/detail-599802.html
Qgis二次開(kāi)發(fā)-QgsAnnotationItem（添加文字、圖片標(biāo)注（支持svg、png、jpg等常用圖片格式））_Mr.codeee的博客-CSDN博客?文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-599802.html
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