• 地图定位实现,地图平移自动


    问题1:当点击某一条数据时将实现地图定位功能,但要如何才能控制定位的缩放呢,按几何对象的大小缩放不是很好,今天特意去观察了下百度,发现百度地图中不管几何对象都大,定位时都是控制了地图的缩放的,故本人实现如下

     1  /// <summary>
     2         /// 使用矩形对象获取定位矩形对象
     3         /// </summary>
     4         /// <param name="enveLope">矩形实例</param>
     5         /// <param name="dScale">定位时,定位信息X、Y最大最小值所占屏幕宽度比例,取值范围为0-1(不包含0包含1,否则将返回原矩形对象) </param>
     6         /// <param name="mindistance">如果矩形实例中xy的最大差值小于这个值,定位将采用这个默认的xy差值进行缩放,默认值为60.0</param>
     7         /// <returns></returns>
     8         public static Geometry GetZoomToGeometry(Envelope enveLope, double dScale, double mindistance)
     9         {
    10             if (mindistance <= 0.0) mindistance = 60.0;
    11             if (dScale <= 0.0 || dScale > 1.0) return enveLope;
    12             double widthX = enveLope.XMax - enveLope.XMin, hightY = enveLope.YMax - enveLope.YMin;
    13             if (widthX < mindistance && hightY < mindistance)
    14             {
    15                 MapPoint minPoint = new MapPoint(enveLope.GetCenter().X - mindistance, enveLope.GetCenter().Y - mindistance);
    16                 MapPoint maxPoint = new MapPoint(enveLope.GetCenter().X + mindistance, enveLope.GetCenter().Y + mindistance);
    17                 return new Envelope(minPoint, maxPoint);
    18             }
    19             else
    20             {
    21                 double xVaue = (widthX / 2.0) / dScale; double yValue = (hightY / 2.0) /dScale;
    22                 MapPoint minPoint = new MapPoint(enveLope.GetCenter().X - xVaue, enveLope.GetCenter().Y - yValue);
    23                 MapPoint maxPoint = new MapPoint(enveLope.GetCenter().X + xVaue, enveLope.GetCenter().Y + yValue);
    24                 return new Envelope(minPoint, maxPoint);
    25             }
    26         }
    View Code

    问题2:在百度地图测距中当鼠标将移出地图时,地图实现自动平移,代码实现

     1  /// <summary>
     2         /// 增加 地图测量时 移至地图边缘时 地图能够相应进行平移操作
     3         /// </summary>
     4         private void BindMeasureMapMouseMoveAction()
     5         {
     6             //设置 绑定地图控件的 鼠标移动事件
     7             this.MapMainMap.MouseMove += (sender, e) =>
     8             {
     9                 if (!IsMeasureAction)
    10                     return;
    11                 Point tmpoint = e.GetPosition(this.MapMainMap);//获取当前鼠标坐标点
    12                 //获取 距离左测边框 和距离上册边框的 距离 以及 上下左右边框的高和宽
    13                 double curWidth = this.MapMainMap.ActualWidth, curHeight = this.MapMainMap.ActualHeight, mouseWidth = tmpoint.X, mouseHeight = tmpoint.Y;
    14                 if (curWidth - mouseWidth < 30 || mouseWidth < 30)//距离左侧过近 或右侧过近 进行平移
    15                 {
    16                     Point tmx = new Point { X = curWidth / 2 + (mouseWidth < 30 ? -50 : 50), Y = curHeight / 2 };//计算平移后中心点距离
    17                     this.MapMainMap.PanTo(this.MapMainMap.ScreenToMap(tmx));//执行平移
    18                 }
    19                 else if (curHeight - mouseHeight < 30 || mouseHeight < 30)//距离上侧过近 或下侧过近 进行平移
    20                 {
    21                     Point tmx = new Point { X = curWidth / 2, Y = curHeight / 2 + (mouseHeight < 30 ? -50 : 50) };//计算平移后中心点距离
    22                     this.MapMainMap.PanTo(this.MapMainMap.ScreenToMap(tmx));//执行平移
    23                 }
    24             };
    25         }
    View Code
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  • 原文地址:https://www.cnblogs.com/kurt/p/4221580.html
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