ArcGis For Silverlight API,地图显示Gis,绘制点，线，绘制图等(三)--绘制点、线、圆，显示提示信息
平台：Vs 2010,Blend 4,Silverlight 4
调用API: ArcGis for Silverligth API(ESRI.ArcGIS.Client)
OK，今天又有空来写点啦，这个例子自己不想拉的太长了，所以这节多写点东西，我尽量把东西都介绍全面，有不懂的可以留言~
有空大家共同讨论。
好进入正题，如今天标题所示，我们先来看画点，线，圆吧！
/// <summary>
/// 绘制界面上的点和线
/// </summary>
/// <param name="myMap"></param>
/// <param name="point"></param>
/// <param name="pointLine"></param>
public void DrawAnimationCompleted(Map myMap, List<Graphic> point,ESRI.ArcGIS.Client.Geometry.PointCollection pointLine)
{
GraphicsLayer gPointLayer = new GraphicsLayer();
GraphicsLayer lineLayer = new GraphicsLayer();
SimpleLineSymbol lineSymbol = new SimpleLineSymbol();
lineSymbol.Color = new SolidColorBrush(Colors.Brown);
lineSymbol.Width = 1;
lineSymbol.Style = SimpleLineSymbol.LineStyle.Solid;
// 画线到图层上并绘制到地图上
GisMap.AddLayersToMap(myMap, new GraphicsLayer[] { lineLayer });
GisLine.DrawLineOnMap(pointLine, lineLayer, lineSymbol);
GisMap.DrawAllLayers(myMap, new GraphicsLayer[] { gPointLayer }, point);
GisMap.AddLayersToMap(myMap, new GraphicsLayer[] { gPointLayer });
}
好，看一下如何画圆吧。
/// <summary>
/// 在地图上绘制圆
/// </summary>
/// <param name="myMap">地图</param>
/// <param name="container">绘制容器</param>
/// <param name="pt">要绘制的点</param>
/// <param name="drawCircleLayer"></param>
/// <param name="circleKm">直径</param>
/// <param name="color">填充色</param>
/// <param name="ellipseStroke">边框色</param>
public void DrawEllipse(Map myMap, Canvas container, MapPoint pt,ref ElementLayer drawCircleLayer, double circleKm,Color color,Color ellipseStroke)
{
if (!drawCircleLayer.Children.Contains(container))
{
drawCircleLayer.Children.Add(container);
container.Opacity = 0.5;
container.SetValue(ElementLayer.EnvelopeProperty, new Envelope(myMap.Extent.XMax, myMap.Extent.YMax, myMap.Extent.XMin, myMap.Extent.YMin));
}
Point ptFirst = myMap.MapToScreen(new MapPoint(Convert.ToDouble(pt.X),
Convert.ToDouble(pt.Y)));
Point pt7 = myMap.MapToScreen(new MapPoint((Convert.ToDouble(pt.X) + circleKm * kmToEN),
Convert.ToDouble(pt.Y)));
Ellipse ellipse7 = new Ellipse();
ellipse7.Width = (pt7.X - ptFirst.X) * 2;
ellipse7.Height = ellipse7.Width;
ellipse7.StrokeThickness = 1;
ellipse7.Stroke = new SolidColorBrush(ellipseStroke);
ellipse7.Fill = new SolidColorBrush(color);
Canvas.SetLeft(ellipse7, ptFirst.X - ellipse7.Width / 2);
Canvas.SetTop(ellipse7, ptFirst.Y - ellipse7.Width / 2);
ellipse7.Opacity = 0.5;
container.Children.Add(ellipse7);
container.IsHitTestVisible = false;
container.SetValue(Canvas.ZIndexProperty, -10);
}
这是一个画圆的方法，需要地图类，点，Canvas容器,Gis 的地图层ElementLayer和color
我前台是这样调用的
/// <summary>
/// 绘制7级风圈和10级风圈
/// </summary>
/// <param name="myMap"></param>
/// <param name="sender"></param>
public void DrawEllipse7And10WindCircle(Map myMap, object sender)
{
if (GisMap.LayerExist(myMap, "WindCircleLayer"))
{ GisMap.DeleteLayersToMap(myMap, "WindCircleLayer"); }
ElementLayer circleLayer = new ElementLayer();
circleLayer.ID = "WindCircleLayer";
Canvas circleCanvas = new Canvas();
Graphic tipGraphic = sender as Graphic;
if (Convert.ToDouble(tipGraphic.Attributes["WindCircle7"]) != 0)
{
Color color = new Color();
color.A = 255;
color.R = 153;
color.G = 105;
color.B = 192;
DrawEllipse(myMap, circleCanvas, new MapPoint(Convert.ToDouble(tipGraphic.Attributes["Longitude"]),
Convert.ToDouble(tipGraphic.Attributes["Latitude"])), ref circleLayer,
Convert.ToDouble(300), color, Colors.Blue);
}
if (Convert.ToDouble(tipGraphic.Attributes["WindCircle10"]) != 0)
{
Color color = new Color();
color.A = 255;
color.R = 111;
color.G = 91;
color.B = 171;
this.DrawEllipse(myMap, circleCanvas, new MapPoint(Convert.ToDouble(tipGraphic.Attributes["Longitude"]),
Convert.ToDouble(tipGraphic.Attributes["Latitude"])), ref circleLayer,
Convert.ToDouble(tipGraphic.Attributes["WindCircle10"]), color, Colors.Blue);
}
GisMap.AddLayersToMap(myMap, new ElementLayer[] { circleLayer });
}
这里的sender是一个Gis元素 Graphic,根据我的WebService 取到的实体后我把这个点加上了Attributes，一系列属性，所以在上面的代码可以看到tipGraphic.Attributes["WindCircle10"],
下面的代码就是在我从WebService取到实体后做添加点的代码:
/// <summary>
/// 添加台风点代码
/// 添加鼠标移入、移出事件
/// </summary>
/// <param name="model"></param>
/// <param name="i"></param>
private void AddPointToGraphic(TyphoonModel model, int i, List<Graphic> pointParam)
{
SimpleMarkerSymbol symbol = new SimpleMarkerSymbol();
Color color = new Color();
color.A = 255;
if (Convert.ToDouble(model.WS) <= 17.1)
{
color.R = 0;
color.G = 254;
color.B = 223;
symbol.Color = new SolidColorBrush(color);
}
else if (Convert.ToDouble(model.WS) > 17.1 && Convert.ToDouble(model.WS) <= 24.4)
{
color.R = 254;
color.G = 243;
color.B = 0;
symbol.Color = new SolidColorBrush(color);
}
else if (Convert.ToDouble(model.WS) > 24.4 && Convert.ToDouble(model.WS) <= 32.6)
{
color.R = 254;
color.G = 144;
color.B = 44;
symbol.Color = new SolidColorBrush(color);
}
else if (Convert.ToDouble(model.WS) > 32.6 && Convert.ToDouble(model.WS) <= 41.4)
{
color.R = 254;
color.G = 4;
color.B = 4; symbol.Color = new SolidColorBrush(color);
}
else if (Convert.ToDouble(model.WS) > 41.4 && Convert.ToDouble(model.WS) <= 50.9)
{
color.R = 254;
color.G = 58;
color.B = 163; symbol.Color = new SolidColorBrush(color);
}
else if (Convert.ToDouble(model.WS) > 50.9)
{
color.R = 174;
color.G = 0;
color.B = 217; symbol.Color = new SolidColorBrush(color);
}
symbol.Size = 10;
if (i == 0)
{
symbol.Style = SimpleMarkerSymbol.SimpleMarkerStyle.Square;
}
else
{
symbol.Style = SimpleMarkerSymbol.SimpleMarkerStyle.Circle;
}
pointParam.Add(new Graphic()
{
Geometry = new MapPoint(model.Longitude, model.Latitude),
Symbol = symbol
});
pointParam[i].Attributes.Add("TyphoonID", model.TyphoonID);
pointParam[i].Attributes.Add("TyphoonNo", model.TyphoonNo);
pointParam[i].Attributes.Add("TyphoonName", model.TyphoonName);
pointParam[i].Attributes.Add("WindCircle7", model.WindCircle7);
pointParam[i].Attributes.Add("WindCircle10", model.WindCircle10);
pointParam[i].Attributes.Add("WS", model.WS);
pointParam[i].Attributes.Add("Pressure", model.Pressure);
pointParam[i].Attributes.Add("IssueTime", model.IssueTime);
pointParam[i].Attributes.Add("Future", model.Future);
pointParam[i].Attributes.Add("Latitude", model.Latitude);
pointParam[i].Attributes.Add("Longitude", model.Longitude);
}
信息提示功能如图:
我们先看下Xmal中的代码:
<Canvas x:Name="typhoonPointInfoCanvas" Visibility="Visible" Height="188" HorizontalAlignment="Left" Margin="0,-272,0,0" VerticalAlignment="Top" Width="360">
<Path Stretch="Fill" Stroke="Black" Height="168.5" Width="328.5" UseLayoutRounding="False" Canvas.Left="0.5" Canvas.Top="-0.5" Data="M113,25 C113,11.745166 123.74516,1.0000004 137,1.0000004 L304,1.0000004 C317.25482,1.0000004 328,11.745166 328,25 L328,144 C328,157.25484 317.25482,168 304,168 L137,168 C123.74516,168 113,157.25484 113,144 z M112.5,24.499998 L0.5,0.5 L112.5,72.499992 z" Fill="{StaticResource CommonGradient2}"/>
<StackPanel Orientation="Vertical" Height="168" Width="176" Canvas.Left="137" Canvas.Top="15">
<TextBlock x:Name="typhoonNameTextBlock" Height="20" Text="名称:" Foreground="White" TextWrapping="Wrap"/>
<TextBlock x:Name="typhoonCollectionTimeTextBlock" Height="20" Text="时间:" Foreground="White" TextWrapping="Wrap" d:LayoutOverrides="HorizontalAlignment"/>
<TextBlock x:Name="typhoonPositionTextBlock" Height="20" Text="位置:" Foreground="White" TextWrapping="Wrap" d:LayoutOverrides="HorizontalAlignment"/>
<TextBlock x:Name="typhoonWSTextBlock" Height="20" Text="最大风速:" Foreground="White" TextWrapping="Wrap" d:LayoutOverrides="HorizontalAlignment"/>
<TextBlock x:Name="typhoonPressureTextBlock" Height="20" Text="中心气压:" Foreground="White" TextWrapping="Wrap" d:LayoutOverrides="HorizontalAlignment"/>
<TextBlock x:Name="typhoonCircle7TextBlock" Height="20" Text="7级风圈半径:" Foreground="White" TextWrapping="Wrap" d:LayoutOverrides="HorizontalAlignment"/>
<TextBlock x:Name="typhoonCircle10TextBlock" Height="20" Text="10级风圈半径:" Foreground="White" TextWrapping="Wrap" d:LayoutOverrides="HorizontalAlignment"/>
</StackPanel>
</Canvas>
<LinearGradientBrush x:Key="CommonGradient" StartPoint="0.5,0" EndPoint="0.5,1"> <GradientStop Offset="0" Color="#ee76a8d3"/> <GradientStop Offset="0.25" Color="#ee5b8cb5"/> <GradientStop Offset="0.75" Color="#ee4b7ba7"/> </LinearGradientBrush>
看下c# 中的代码:
当我们添加那些点也就是 Graphic 的时候有这样一个事件MouseEventHandler
// 添加点和线，先显示点层，动画结束后显示线层
mapDraw.DrawLineAndPoint(ref point, myMap, gLayer, ref pointLine, e, length);
// 添加点事件
foreach (Graphic item in point)
{
item.MouseEnter += new MouseEventHandler(MainPage_MouseEnter);
item.MouseLeave += new MouseEventHandler(MainPage_DrawLine);
}
/// <summary>
/// 绘制单条台风动画前的信息
/// </summary>
/// <param name="point"></param>
/// <param name="myMap"></param>
/// <param name="gLayer"></param>
/// <param name="pointLine"></param>
/// <param name="e"></param>
/// <param name="length"></param>
public void DrawLineAndPoint(ref List<Graphic> point,Map myMap,GraphicsLayer gLayer,
ref ESRI.ArcGIS.Client.Geometry.PointCollection pointLine, GetTyphoonsCompletedEventArgs e, int length)
{
#region 添加点代码
point = new List<Graphic>();
for (int i = 0; i < length; i++)
{
AddPointToGraphic(e.Result[i], i, point);
}
#endregion
// 添加线的代码
pointLine = new ESRI.ArcGIS.Client.Geometry.PointCollection();
AddLineToMap(e.Result.ToList(), length, pointLine);
// 显示点层
GisMap.DrawAllLayers(myMap, new GraphicsLayer[] { gLayer }, point);
GisMap.AddLayersToMap(myMap, new GraphicsLayer[] { gLayer });
}
AddPointToGraphic这个方法就是图片上面的那段代码
item.MouseEnter += new MouseEventHandler(MainPage_MouseEnter);
item.MouseLeave += new MouseEventHandler(MainPage_DrawLine);
这两段代码就是我们添加鼠标移入和移出事件了，我们看下移入事件:
void MainPage_MouseEnter(object sender, MouseEventArgs e) { Graphic graphic = sender as Graphic; Cursor = Cursors.Hand; typhoonPointInfoCanvas.Visibility = Visibility.Visible; Point pt = myMap.MapToScreen(new MapPoint(Convert.ToDouble(graphic.Attributes["Longitude"]), Convert.ToDouble(graphic.Attributes["Latitude"]))); typhoonPointInfoCanvas.SetValue(Grid.MarginProperty, new Thickness(pt.X, pt.Y, 0, 0)); typhoonNameTextBlock.Text = "台风：" + graphic.Attributes["TyphoonName"].ToString(); typhoonCollectionTimeTextBlock.Text = "时间：" + graphic.Attributes["IssueTime"].ToString(); typhoonPositionTextBlock.Text = "位置：" + graphic.Attributes["Longitude"].ToString() + "°E," + graphic.Attributes["Latitude"].ToString() + "°N"; typhoonWSTextBlock.Text = "最大风速：" + graphic.Attributes["WS"].ToString() + " m/s"; typhoonPressureTextBlock.Text = "中心气压：" + graphic.Attributes["Pressure"].ToString() + " hPa"; typhoonCircle7TextBlock.Text = "7级风圈半径：" + graphic.Attributes["WindCircle7"].ToString() + " km"; typhoonCircle10TextBlock.Text = "10级风圈半径：" + graphic.Attributes["WindCircle10"].ToString() + " km"; circle.DrawEllipse7And10WindCircle(myMap, sender); selectedGarphic = sender as Graphic; }
我们看到在显示信息的同时我们又把圆画了上去DrawEllipse7And10WindCircle()这个函数
GisMap是个静态类，以下是他的代码
/// <summary>
/// ArcGis 调用类
/// 动态加载、显示隐藏层数据、加载层上的点等
/// 日期：2010-5-10
/// 作者：AngelSoft
/// </summary>
public static class GisMap
{
/// <summary>
/// 绘制所有的点到地图上
/// </summary>
/// <param name="glayer"></param>
/// <param name="cacheGraphic"></param>
public static void DrawSymbol(GraphicsLayer glayer, List<Graphic> cacheGraphic)
{
if (glayer != null)
{
int graphicCount = cacheGraphic.Count;
for (int i = 0; i < graphicCount; i++)
{
glayer.Graphics.Add(cacheGraphic[i]);
} // i
}
}
/// <summary>
/// 加载所有图层上的点
/// 动态绘制
/// 图层和点的对应关系要正确
/// 有几个图层就要有几个点集合
/// </summary>
/// <param name="map">ArcGis 地图变量</param>
/// <param name="layers">GraphicLayer 层数组</param>
/// <param name="graphicParam">Graphic 点数组</param>
public static void DrawLayers(Map map, GraphicsLayer[] layers, params List<Graphic>[] graphicParam)
{
// 计算要绘制的层数并一层一层的绘制(调用动态绘制方法)
if (layers != null)
{
int length = layers.Length;
for (int i = 0; i < length; i++)
{
if (layers[i] == null)
{
layers[i] = new GraphicsLayer();
}
DynamicDrawSymbol(layers[i], graphicParam[i], map);
}
}
}
/// <summary>
/// 加载所有图层上的点
/// 画所有点
/// 图层和点的对应关系要正确
/// 有几个图层就要有几个点集合
/// </summary>
/// <param name="map">ArcGis 地图变量</param>
/// <param name="layers">GraphicLayer 层数组</param>
/// <param name="graphicParam">Graphic 点数组</param>
public static void DrawAllLayers(Map map, GraphicsLayer[] layers, params List<Graphic>[] graphicParam)
{
// 计算要绘制的层数并一层一层的绘制(调用动态绘制方法)
if (layers != null)
{
int length = layers.Length;
for (int i = 0; i < length; i++)
{
if (layers[i] == null)
{
layers[i] = new GraphicsLayer();
}
DrawAllGraphics(layers[i], graphicParam[i]);
}
}
}
/// <summary>
/// 隐藏或显示 ArcGis 层
/// </summary>
/// <param name="show">隐藏或显示</param>
/// <param name="layers">层</param>
public static void LayersVisibility(bool show, params GraphicsLayer[] layers)
{
if (layers != null)
{
foreach (GraphicsLayer item in layers)
{
item.Visible = show;
}
}
}
/// <summary>
/// 将图层数组全部从 map 中移除
/// </summary>
/// <param name="map">表示一张 ArcGis 地图</param>
/// <param name="layers">表示地图层的数组</param>
public static void DeleteLayersToMap(Map map, GraphicsLayer[] layers)
{
// 逐个将数据移除
foreach (GraphicsLayer item in layers)
{
map.Layers.Remove(item);
}
}
/// <summary>
/// 根据 ID 号删除某层
/// </summary>
/// <param name="map"></param>
/// <param name="ID"></param>
/// <returns></returns>
public static void DeleteLayersToMap(Map map, string[] ID)
{
int length = ID.Length;
for (int i = 0; i < length; i++)
{
foreach (Layer item in map.Layers)
{
if (item.ID == ID[i])
{
map.Layers.Remove(item);
length--;
break;
}
}
}
}
/// <summary>
/// 将图层数组全部从 map 中移除
/// </summary>
/// <param name="map">表示一张 ArcGis 地图</param>
/// <param name="layers">表示地图层的数组</param>
public static void DeleteLayersToMap(Map map, ElementLayer[] layers)
{
// 逐个将数据移除
foreach (ElementLayer item in layers)
{
map.Layers.Remove(item);
}
}
/// <summary>
/// 删除地图上的某一层
/// </summary>
/// <param name="myMap"></param>
/// <param name="ID">ID号</param>
public static void DeleteLayersToMap(Map myMap, string ID)
{
int layers = myMap.Layers.Count;
for (int i = 0; i < layers; i++)
{
if (myMap.Layers[i].ID == ID)
{
myMap.Layers.RemoveAt(i);
return;
}
}
}
public static bool LayerExist(Map myMap, string ID)
{
int layers = myMap.Layers.Count;
for (int i = 0; i < layers; i++)
{
if (myMap.Layers[i].ID == ID)
{
return true;
}
}
return false;
}
/// <summary>
/// 将图层数组全部添加到 map 中
/// </summary>
/// <param name="map">表示一张 ArcGis 地图</param>
/// <param name="layers">表示地图层的数组</param>
public static void AddLayersToMap(Map map, GraphicsLayer[] layers)
{
// 逐个将数据添加到当前地图中
foreach (GraphicsLayer item in layers)
{
if (item != null)
{
map.Layers.Add(item);
}
}
}
/// <summary>
/// 将图层数组全部添加到 map 中
/// </summary>
/// <param name="map">表示一张 ArcGis 地图</param>
/// <param name="layers">表示地图层的数组</param>
public static void AddLayersToMap(Map map, ElementLayer[] layers)
{
// 逐个将数据添加到当前地图中
foreach (ElementLayer item in layers)
{
map.Layers.Add(item);
}
}
/// <summary>
/// 绘制所有的点到地图上
/// </summary>
/// <param name="eLayer"></param>
/// <param name="image"></param>
public static void AddImageToElementLayer(ElementLayer eLayer, List<Image> image)
{
if (eLayer != null)
{
foreach (Image item in image)
{
eLayer.Children.Add(item);
}
}
}
/// <summary>
/// 隐藏或显示 ArcGis 层
/// </summary>
/// <param name="show">隐藏或显示</param>
/// <param name="layers">层</param>
public static void LayersVisibility(bool show, params ElementLayer[] layers)
{
if (layers != null)
{
foreach (ElementLayer item in layers)
{
item.Visible = show;
}
}
}
/// <summary>
/// 动态加载图层
/// 使用 ElementLayer 层
/// </summary>
/// <param name="eLayer"></param>
/// <param name="cacheGraphic"></param>
/// <param name="map"></param>
public static void DynamicDrawElementLayer(ElementLayer eLayer, List<UIElement> cacheElement, Map map)
{
// 以下四个变量分别表示地图的四个边
// 即最大经纬度和最小经纬度
// xMax最大经度,yMax最大纬度
double xMax = map.Extent.XMax + 2;
double xMin = map.Extent.XMin - 2;
double yMax = map.Extent.YMax + 2;
double yMin = map.Extent.YMin - 2;
// 去除不在坐标范围内的点,先检查图层是否为空
if (eLayer != null)
{
int graphicCount = eLayer.Children.Count;
for (int i = 0; i < graphicCount; i++)
{
UIElement element = eLayer.Children[i];
// 判断经度,纬度
if (!(((element.GetValue(ElementLayer.EnvelopeProperty) as Envelope).Extent.XMax < xMax && (element.GetValue(ElementLayer.EnvelopeProperty) as Envelope).Extent.XMax > xMin)
&& ((element.GetValue(ElementLayer.EnvelopeProperty) as Envelope).Extent.YMax < yMax && (element.GetValue(ElementLayer.EnvelopeProperty) as Envelope).Extent.YMax > yMin)))
{
// 将点在地图上移除,并放在缓存中
cacheElement.Add(eLayer.Children[i]);
eLayer.Children.Remove(eLayer.Children[i]);
graphicCount--; // 当从集合中移除元素时应该把 graphicCount 减1
i--; // 元素被移除后相当于当前元素的后一位元素会 -1,应该再循环一次本次循环所以应该 -1
}
} // i
}
// 检查缓存是否为空,并将点绘制到图形上
if (cacheElement != null)
{
int count = cacheElement.Count;
for (int i = 0; i < count; i++)
{
// 判断经度,纬度
if (((cacheElement[i].GetValue(ElementLayer.EnvelopeProperty) as Envelope).Extent.XMax < xMax && (cacheElement[i].GetValue(ElementLayer.EnvelopeProperty) as Envelope).Extent.XMax > xMin)
&& ((cacheElement[i].GetValue(ElementLayer.EnvelopeProperty) as Envelope).Extent.YMax < yMax && (cacheElement[i].GetValue(ElementLayer.EnvelopeProperty) as Envelope).Extent.YMax > yMin))
{
// 运行到此则该点在目前地图范围内,将该点加入到地图中
eLayer.Children.Add(cacheElement[i]);
cacheElement.Remove(cacheElement[i]);
count--; // 当从集合中移除元素时应该把 count 减1
i--; // 元素被移除后相当于当前元素的后一位元素会 -1,应该再循环一次本次循环所以应该 -1
continue;
}
}
}
}
/// <summary>
/// 将所有元素画到地图上
/// </summary>
/// <param name="eLayer"></param>
/// <param name="cacheElement"></param>
public static void DrawAllUIElement(ElementLayer eLayer, List<UIElement> cacheElement)
{
if (eLayer != null)
{
foreach (UIElement item in cacheElement)
{
eLayer.Children.Add(item);
}
}
}
/// <summary>
/// 动态的绘制图层
/// 当然地图移动到相应的坐标后绘制(保留原来的点,绘制新的数据)
/// 实现了无刷新绘制
/// </summary>
/// <param name="glayer">表示地图上的层</param>
/// <param name="cacheGraphic">存放 Graphics 的缓存</param>
/// <param name="map">表示一张 ArcGis 地图</param>
private static void DynamicDrawSymbol(GraphicsLayer glayer, List<Graphic> cacheGraphic, Map map)
{
// 以下四个变量分别表示地图的四个边
// 即最大经纬度和最小经纬度
// xMax最大经度,yMax最大纬度
double xMax = map.Extent.XMax + 2;
double xMin = map.Extent.XMin - 2;
double yMax = map.Extent.YMax + 2;
double yMin = map.Extent.YMin - 2;
// 去除不在坐标范围内的点,先检查图层是否为空
if (glayer != null)
{
int graphicCount = glayer.Graphics.Count;
for (int i = 0; i < graphicCount; i++)
{
// 判断经度,纬度
if (!((glayer.Graphics[i].Geometry.Extent.XMax < xMax && glayer.Graphics[i].Geometry.Extent.XMax > xMin)
&& (glayer.Graphics[i].Geometry.Extent.YMax < yMax && glayer.Graphics[i].Geometry.Extent.YMax > yMin)))
{
// 将点在地图上移除,并放在缓存中
cacheGraphic.Add(glayer.Graphics[i]);
glayer.Graphics.Remove(glayer.Graphics[i]);
graphicCount--; // 当从集合中移除元素时应该把 graphicCount 减1
i--; // 元素被移除后相当于当前元素的后一位元素会 -1,应该再循环一次本次循环所以应该 -1
}
} // i
}
// 检查缓存是否为空,并将点绘制到图形上
if (cacheGraphic != null)
{
int count = cacheGraphic.Count;
for (int i = 0; i < count; i++)
{
// 判断经度,纬度
if ((cacheGraphic[i].Geometry.Extent.XMax < xMax && cacheGraphic[i].Geometry.Extent.XMax > xMin)
&& (cacheGraphic[i].Geometry.Extent.YMax < yMax && cacheGraphic[i].Geometry.Extent.YMax > yMin))
{
// 运行到此则该点在目前地图范围内,将该点加入到地图中
glayer.Graphics.Add(cacheGraphic[i]);
cacheGraphic.Remove(cacheGraphic[i]);
count--; // 当从集合中移除元素时应该把 count 减1
i--; // 元素被移除后相当于当前元素的后一位元素会 -1,应该再循环一次本次循环所以应该 -1
continue;
}
}
}
}
/// <summary>
/// 将所有元素画到地图上
/// </summary>
/// <param name="eLayer"></param>
/// <param name="cacheElement"></param>
private static void DrawAllGraphics(GraphicsLayer eLayer, List<Graphic> cacheGraphic)
{
if (eLayer != null)
{
foreach (Graphic item in cacheGraphic)
{
eLayer.Graphics.Add(item);
}
}
}
}
今天把 GisMap 这个类都写出来了也为了我写下一篇文章做准备吧！后面会写一篇动态加载数据点的文章！因为当大批量点(2000)左右加载到地图上的时候，
就会非常的卡，基本都动不了，所以我们要动态去加载这些点。
