how to mark a point on image.Image is already draw on QLabel and set using setPixmap

[scascio]

It's true it's a little bit hard to follow what you did and there is many solutions to do what you want :

You can overload the PainEvent of your widget, call the parent method, then draw your point after label is painted. The position may be saved in a proper mouseEvent.

Or inherit QLabel, and in overloaded paintEvent, call the parent method, then draw your point.

Maybe your problem is that your are not calling the parent method in the paintEvent, so result of drawing the point is visible only where there is no image

[bpatel]

ok here is my code

this is my widget .cpp file

Widget() //constructor
{
Label1=new QLabel(this);
button=new QPushButton(this);
Point->setx(0):
point->sety(0);
connect(button,SIGNAL(clicked()),this,SLOT(open()) );
}

void Widget:pen()
{
Image("E:\\new.tif"); //Image is object of QImage class declare in header file
Label1.setPix(Qt::Pixmap.fromImage(Image)); //that will draw image on QLabel
}

void Widget::QPaintEvent(QPaintEvent *e)
{
QPainter painter(this);
draw(&painter);
}

void Widget::draw(QPainter *painter)
{
Qimage imageicon("E:\\icon.png");
painter.drawImage(point,imageicon);
}

void Widget::mousePressEvent(QMousePressEvent *e)
{
point->setX(e->X()); //getting coordinate of image where i want to draw icon
point->setY(e->Y());
}

if there is something missing in code or some syntax error plz assume right one ...

now u get some idea about my code here my problem is that after clicking on a button it will set image on label then i clicked on that image i want icon at that place where i click but it will not appear on image it is behind the image
so my problem is that instead of QPainter painter(this)
can i write
QPainter painter(Label1);
so i can click on image that will draw icon on image.
which will return me something using that i can draw or mark on image
actually i m working in GIS field so i want to mark some point on image.....like i want to mark some house or some road or some palce.........my image is satellite image.......

[wysota]

Did you try compiling this code? IMO it won't compile.

You need to call the base class implementation in the paint event, that's for sure.

[scascio]

To answer your question, just call the base class in your paintEvent:

void Widget::paintEvent(QPaintEvent * event) {
  //this will draw your widget, and therefore the label too
  QWidget::paintEvent(event);
 
  //then draw your point 
  Qpainter painter(this);
  painter.drawPoint(x, y);
}

void Widget::paintEvent(QPaintEvent * event) {
  //this will draw your widget, and therefore the label too
  QWidget::paintEvent(event);

  //then draw your point 
  Qpainter painter(this);
  painter.drawPoint(x, y);
}

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But to answer your problem, if you are trying to implement a GIS engine with QLabeland painting points, maybe you should better read the documentation about about QGraphicsViewand QGraphicsPixmapItem.

[bpatel]

@above
tbahks yaar for reply