5

我想根据鼠标移动移动矩形。请参考以下链接。

http://atomicrobotdesign.com/blog_media/draw/draw1.html

在 mousedown 事件中获取矩形开始位置并开始拖动它将在鼠标移动事件中创建矩形。但是当我移动到上一个值时（即移动到小于鼠标按下的值意味着它将返回负值）所以宽度变为负值。

上面的链接是画布矩形。但我创建了具有相同逻辑的 svg 矩形。

不支持矩形的负宽度？或者我如何根据鼠标移动移动矩形？

怎么了？

我的代码片段。

ChartMouseDown:function(e){

//       e = this.normalizeMouseEvent(e);


      var mousedownCords=this.calMousePosition(e);
      this.mouseDownX=mousedownCords.X;
      this.mouseDownY=mousedownCords.Y;

      this.chartMouseDownPoint= this.GetValuebyPoint(Math.abs(this.mouseDownX-this.model.m_AreaBounds.X),Math.abs(this.mouseDownY-(this.model.m_AreaBounds.Y + this.model.m_AreaBounds.Height)));
      this.zoomingX=true;

    },



ChartMouseMove: function (evt) {

    if( this.zoomingX)
    {

    var mouseMoveX,mouseMoveY;

     var mouseMoveCords=this.calMousePosition(evt);
      mouseMoveX=mouseMoveCords.X;
      mouseMoveY=mouseMoveCords.Y;
      $(this.ZoomAreaRect).remove();
      var width =  Math.abs(mouseMoveX - this.mouseDownX);
      var height = mouseMoveY - this.mouseDownY;
      var x;
      if(mouseMoveX > this.mouseDownX)
      x= this.mouseDownX;
      else
      x= mouseMoveX;

       this.ZoomAreaRect = document.createElementNS("http://www.w3.org/2000/svg", "rect");

        $(this.ZoomAreaRect).attr({
            'id': 'ZoomArea', 'x': x, 'y': this.model.m_AreaBounds.Y, 'width': width, 'height': this.model.m_AreaBounds.Height,
            'fill': 'gray', 'stroke-width': 1, 'stroke':'gray'
        });

       $(this.ZoomAreaRect).appendTo(this.SvgObject);

    }


 calMousePosition:function(e)
    {
     var matched = jQuery.uaMatch( navigator.userAgent );
     var browser = {};
     var mouseX,mouseY;
     if(matched.browser.toLowerCase()=="mozilla")
        {
        mouseX = (e.pageX)-  $(this.SvgObject).parent().offset().left;
        mouseY=  (e.pageY) - $(this.SvgObject).parent().offset().top;
        }
        else
        {
        mouseX =  (e.pageX +document.documentElement.scrollLeft)-$(this.SvgObject).offset().left;
        mouseY =  (e.pageY + document.documentElement.scrollTop) - $(this.SvgObject).offset().top;
        }

        return { X: mouseX, Y:mouseY};

    },

谢谢，

湿婆

4

3 回答 3

11

If you want to implement this in SVG you'll have to make sure the rectangles width/height are always positive and calculate the x/y accordingly.

于 2013-03-24T13:00:20.250 回答
1

如果你有两个坐标数组开始和结束，(start[0],start[1])左上角（或右下角）和(end[0],end[1])左上角（或右下角）然后这是绘制该矩形的算法，它不关心这些坐标是否被切换

              <rect
                fill="rgba(255,0,0,0.3)"
                x={Math.min(start[0], end[0])}
                y={Math.min(start[1], end[1])}
                width={Math.abs(start[0] - end[0])}
                height={Math.abs(start[1] - end[1])}
              />
于 2020-04-15T04:59:11.067 回答
0

您可以使用多边形而不是矩形，点为

points={`${x},${y} ${x + width},${y} ${x + width},${y + height} ${x},${y + height}`}
于 2022-01-15T12:06:33.400 回答