首先来看看实现的效果:
比较丑陋,还望大家见怪,呵呵~~~,接下来给大家看看设计的界面吧:
界面比较丑陋,主要控件为: 四个combox,三个textbox和两个按钮,属性值设置在此不详述,还望见谅…… 下面看看实现代码:
1、窗体加载事件:
/// <summary>
/// 窗体加载
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void formLabel_Load(object sender, EventArgs e)
{
//字体大小
for (int i = 5; i < 73; i++)
{
this.cmbFontsSize.Items.Add(i.ToString());
}
//字体样式
string[] strFontsStyle = new string[] {"宋体","Times New Roman","隶书","黑体","仿宋","新宋体","幼圆" };
for (int i = 0; i < strFontsStyle.Length; i++)
{
this.cmbFontsStyle.Items.Add(strFontsStyle[i]);
}
//添加图层
AddLayers();
}
此处,调用了AddLayers这个方法,其代码为:
/// <summary>
/// 添加图层
/// </summary>
private void AddLayers()
{
//首先清除
cmbLayers.Items.Clear();
//加载图层,默认选择第一个图层
int layerCount = _mapControl.LayerCount;
for (int i = 0; i < layerCount; i++)
{
cmbLayers.Items.Add(_mapControl.get_Layer(i).Name);
}
if (layerCount != 0)
{
cmbLayers.SelectedIndex = 0;
}
}
在窗体加载事件中,完成了图层的加载,以及字体大小,字体样式值等的初始化工作,接着,图层cmbLayers的选择改变事件,实现加载该图层的字段,详细代码如下:
/// <summary>
/// 显示字段
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void cmbLayers_SelectedIndexChanged(object sender, EventArgs e)
{
//清空字段列表
cmbFields.Items.Clear();
//改变字段列表
//获取选择的图层
IFeatureLayer featureLayer = _mapControl.get_Layer(cmbLayers.SelectedIndex) as IFeatureLayer;
IFeatureClass featureClass = featureLayer.FeatureClass;
int fieldsCount = featureClass.Fields.FieldCount;
for (int i = 0; i < fieldsCount; i++)
{
IField field = featureClass.Fields.get_Field(i);
//除去Shape字段
if (field.Name == "Shape")
{
continue;
}
cmbFields.Items.Add(field.Name);
}
}
到此,标注样式的设置工作业已完成,接下来就是要进行对图层进行标注了,看看那个“确定”按钮的事件:
/// <summary>
/// 添加标注
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnOk_Click(object sender, EventArgs e)
{
AddLabel addlabel = new AddLabel();
ILayer mLayer = _mapControl.get_Layer(cmbLayers.SelectedIndex) as ILayer;
addlabel.AddAnnotate(mLayer, this.cmbFields.Text, cmbFontsStyle.Text, double.Parse(cmbFontsSize.Text), int.Parse(txtR.Text), int.Parse(txtG.Text), int.Parse(txtB.Text));
_mapControl.ActiveView.Refresh();
this.Close();
}
在该按钮事件中调用了AddLabel这个类的AddAnnotate方法,在AddAnnotate方法中包含7个参数,标注的图层,标注字段,字体大小,字体样式以及字体颜色的RGB值,类AddLabel的代码如下:
using System;
using System.Collections.Generic;
using System.Linq;
//ArcEngine引用
using ESRI.ArcGIS.Carto;
using ESRI.ArcGIS.Display;
using stdole;
namespace MapDemo
{
public class AddLabel
{
private GetRgbColor getrgbcolor = new GetRgbColor();
//添加标注,比TextElment功能更强大
public void AddAnnotate(ILayer layer, string fieldName,string fontFamily,double fontSize,int colorR,int colorG,int colorB)
{
IGeoFeatureLayer pGeoLayer = layer as IGeoFeatureLayer;
IAnnotateLayerPropertiesCollection IPALPColl = pGeoLayer.AnnotationProperties;
IPALPColl.Clear();
IRgbColor pColor = getrgbcolor.GetRGBColor(colorR, colorG, colorB);
IFontDisp pFont = new StdFont()
{
Name = fontFamily,
Bold = true
} as IFontDisp;
ITextSymbol pTextSymbol = new TextSymbolClass()
{
Color = pColor,
Font = pFont,
Size = fontSize
};
//用来控制标注和要素的相对位置关系
ILineLabelPosition pLineLpos = new LineLabelPositionClass()
{
Parallel = false, //修改标注的属性
Perpendicular = true,
InLine = true
};
//用来控制标注冲突
ILineLabelPlacementPriorities pLinePlace = new LineLabelPlacementPrioritiesClass()
{
AboveStart = 5, //让above 和start的优先级为5
BelowAfter = 4
};
//用来实现对ILineLabelPosition 和 ILineLabelPlacementPriorities以及更高级属性的控制
IBasicOverposterLayerProperties pBOLP = new BasicOverposterLayerPropertiesClass()
{
FeatureType = esriBasicOverposterFeatureType.esriOverposterPolygon,
LineLabelPlacementPriorities = pLinePlace,
LineLabelPosition = pLineLpos
};
//创建标注对象
ILabelEngineLayerProperties pLableEngine = new LabelEngineLayerPropertiesClass()
{
Symbol = pTextSymbol,
BasicOverposterLayerProperties = pBOLP,
IsExpressionSimple = true,
Expression = "[" + fieldName + "]"
};
//设置标注的参考比例尺
IAnnotateLayerTransformationProperties pAnnoLyrPros = pLableEngine as IAnnotateLayerTransformationProperties;
pAnnoLyrPros.ReferenceScale = 2500000;
//设置标注可见的最大最小比例尺
IAnnotateLayerProperties pAnnoPros = pLableEngine as IAnnotateLayerProperties;
pAnnoPros.AnnotationMaximumScale = 2500000;
pAnnoPros.AnnotationMinimumScale = 25000000;
//pAnnoPros.WhereClause属性 设置过滤条件
IPALPColl.Add(pAnnoPros);
pGeoLayer.DisplayAnnotation = true;
}
}
}
至此,已完成标注工作,那个取消按钮就不说了。 总结一下,本实例完成了对图层属性的标注,但存在以下问题: 1、不能够随地图的放大与缩小而产生相对应的放大或者缩小的变化; 2、对于标注的重叠没有处理; 3、没实现控制其摆放位置和方向。 后续还会继续对之上述问题进行优化,还望大家多多支持与鼓励!同时,有能解决上述方法的同仁还望不吝赐教!