QGis添加图层后可以用鼠标滚动缩放,如果想添加图标到工具栏实现相同的效果,如图:
(1)在QMainWindow中添加如下变量:
QToolBar *mpMapToolBar; ///<地图操作相关的工具栏 QgsMapTool *mpPanTool; ///<漫游 QgsMapTool *mpZoomInTool;///<放大 QgsMapTool *mpZoomOutTool;///<缩小 QgsMapTool *mpZoomFull; ///<全图显示
在Qt设计师里面添加Action:
(2)然后在初始化函数里添加:
//添加工具栏上按钮
mpMapToolBar = addToolBar(tr("Tools"));
mpMapToolBar->addSeparator();
mpMapToolBar->addAction(ui.mpActionPan);
mpMapToolBar->addAction(ui.mpActionZoomIn);
mpMapToolBar->addAction(ui.mpActionZoomOut);
mpMapToolBar->addAction(ui.mpActionZoomFull);
mpPanTool= new QgsMapToolPan(mainMapCanvas);
mpPanTool->setAction(ui.mpActionPan);
mpZoomInTool = new QgsMapToolZoom(mainMapCanvas,false);
mpZoomInTool->setAction(ui.mpActionZoomIn);
mpZoomOutTool = new QgsMapToolZoom(mainMapCanvas,true);
mpZoomOutTool->setAction(ui.mpActionZoomOut); (3)添加信号槽函数连接:
connect(ui.mpActionPan,SIGNAL(triggered()),this,SLOT(panMode())); connect(ui.mpActionZoomIn,SIGNAL(triggered()),this,SLOT(zoomInMode())); connect(ui.mpActionZoomOut,SIGNAL(triggered()),this,SLOT(zoomOutMode())); connect(ui.mpActionZoomFull, SIGNAL(triggered()), this, SLOT(zoomFull()));(4)槽函数实现:
void MainWindow::zoomInMode()
{
mainMapCanvas->setMapTool(mpZoomInTool);
if ( mainMapCanvas->layer(0)->type() == QgsMapLayer::RasterLayer)
{
return;
}
QgsVectorLayer *pLayer=(QgsVectorLayer *)mainMapCanvas->layer(0);
pLayer->removeSelection(true);
}
void MainWindow::zoomOutMode()
{
mainMapCanvas->setMapTool(mpZoomOutTool);
if ( mainMapCanvas->layer(0)->type() == QgsMapLayer::RasterLayer)
{
return;
}
QgsVectorLayer *pLayer=(QgsVectorLayer *)mainMapCanvas->layer(0);
pLayer->removeSelection(true);
}
void MainWindow::panMode()
{
mainMapCanvas->setMapTool(mpPanTool);
ui.mpActionPan->setCheckable(true);
ui.mpActionPan->setChecked(true);
if ( mainMapCanvas->layer(0)->type() == QgsMapLayer::RasterLayer)
{
return;
}
QgsVectorLayer *pLayer=(QgsVectorLayer *)mainMapCanvas->layer(0);
pLayer->removeSelection(true);
}
void MainWindow::zoomFull()
{
mainMapCanvas->zoomToFullExtent();
if ( mainMapCanvas->layer(0)->type() == QgsMapLayer::RasterLayer)
{
return;
}
QgsVectorLayer *pLayer=(QgsVectorLayer *)mainMapCanvas->layer(0);
pLayer->removeSelection(true);
}上面的mainMapCanvas就是已经加载了矢量图层的。
QGis(二)添加缩放漫游工具栏,布布扣,bubuko.com
原文:http://blog.csdn.net/tszhangjunqiao/article/details/38518291