kineticjs - 如何从一条线上获得点数

Question

If I create a line...

 var line = new Kinetic.Line({
  points: [0 , 5, 0, 100],
  stroke: 'black',
  strokeWidth: 2,
  draggable: true

});

And I attach a event...

   line.on("mouseup", function () {
      updateLineInput( this.attrs.points );
   });

How could I get the points back out? this.attrs.points does not work...

Answer 1

You can get the points with line.getPoints() but they usually don't change after dragging and dropping, the X, Y coordinates change which the relative points are drawn from. You can get those with line.getX() and line.getY()

  //It would be better to use the 'dragend' event if you want it to fire on a drag/drop
  line.on('dragend', function() {

    //You may really want the coordinates too
    var x = line.getX();
    var y = line.getY();

    //But this is what you asked for:
    var points = line.getPoints();
    updateLineInput(points);
  });

Answer 2

I concur with nak but I would recommend:

 //It would be better to use the 'dragend' event if you want it to fire on a drag/drop
  line.on('dragend', function(evt) {
     var myline=evt.shape;
    //You may really want the coordinates too
    var x = myline.getX();
    var y = myline.getY();

    //But this is what you asked for:
    var points = myline.getPoints();

    var mynewpoints=manipulate(points);
    myline.setPoints(mynewpoints);
    var mylayer=myline.getLayer();
    mylayer.draw();
  });