public GISLine(List <GISVertex> _vertexes)
{
Vertexes = _vertexes;
centroid = GISTools.CalculateCentroid(_vertexes);
extent = GISTools.CalculateExtent(_vertexes);
length = GISTools.CalculateLength(_vertexes);
}
public GISPolygon(List <GISVertex> _vertexes)
{
Vertexes = _vertexes;
centroid = GISTools.CalculateCentroid(_vertexes);
extent = GISTools.CalculateExtent(_vertexes);
Area = GISTools.CalculateArea(_vertexes);
}
static void WriteFields(List <GISField> fields, BinaryWriter bw)
{
for (int fieldindex = 0; fieldindex < fields.Count; fieldindex++)
{
GISField field = fields[fieldindex];
bw.Write(GISTools.TypeToInt(field.datatype)); //字段类型
GISTools.WriteString(field.name, bw); //字段名
}
}
//点到线实体的距离计算 //可以算出最短的距离 但无法获知最近的位置
public double Distance(GISVertex vertex)
{
double distance = Double.MaxValue;
for (int i = 0; i < Vertexes.Count - 1; i++)
{
distance = Math.Min(GISTools.PointToSegment
(Vertexes[i], Vertexes[i + 1], vertex), distance);
}
return(distance);
}
//*************
//从文件中读取字段信息
static List <GISField> ReadFields(BinaryReader br, int FieldCount)
{
List <GISField> fields = new List <GISField>();
for (int fieldindex = 0; fieldindex < FieldCount; fieldindex++)
{
Type fieldtype = GISTools.IntToType(br.ReadInt32());
string fieldname = GISTools.ReadString(br);
fields.Add(new GISField(fieldtype, fieldname));
}
return(fields);
}
//写文件函数主框架
public static void WriteFile(GISLayer layer, string filename)
{
FileStream fsr = new FileStream(filename, FileMode.Create); //根据文件名创建文件流
BinaryWriter bw = new BinaryWriter(fsr);
WriteFileHeader(layer, bw); //写入头文件
GISTools.WriteString(layer.Name, bw); //写入图层名字
WriteFields(layer.Fields, bw); //写入字段
WriteFeatures(layer, bw);
bw.Close();
fsr.Close();
}
static void WriteFileHeader(GISLayer layer, BinaryWriter bw)//bw是与文件相连的文件写入工具
{
MyFileHeader mfh = new MyFileHeader();
mfh.MinX = layer.Extent.getMinX();
mfh.MinY = layer.Extent.getMinY();
mfh.MaxX = layer.Extent.getMaxX();
mfh.MaxY = layer.Extent.getMaxY();
mfh.FeatureCount = layer.FeatureCount();
mfh.Shapetype = (int)(layer.ShapeType);
mfh.FieldCount = layer.Fields.Count;
bw.Write(GISTools.ToBytes(mfh));
}
static ShapefileHeader ReadFileHeader(BinaryReader br) //用于读取文件头的函数
{ //*************************************
/*
* byte[] buff = br.ReadBytes(Marshal.SizeOf(typeof(ShapefileHeader)));
* GCHandle handle = GCHandle.Alloc(buff, GCHandleType.Pinned);//handle读取buff数组在内存中的指针
* //指针指向的内存被映射给一个结构体实例header
* ShapefileHeader header = (ShapefileHeader)Marshal.PtrToStructure
* (handle.AddrOfPinnedObject(), typeof(ShapefileHeader));
* handle.Free(); //释放内存 将其还给C#管理
* return header;
*/
return((ShapefileHeader)GISTools.FromBytes(br, typeof(ShapefileHeader)));
}
public static GISLayer ReadFile(string filename)
{
FileStream fsr = new FileStream(filename, FileMode.Open);
BinaryReader br = new BinaryReader(fsr);
MyFileHeader mfh = (MyFileHeader)(GISTools.FromBytes(br, typeof(MyFileHeader))); //读取文件头
SHAPETYPE ShapeType = (SHAPETYPE)Enum.Parse(typeof(SHAPETYPE), mfh.Shapetype.ToString()); //获取空间实体类型shapetype和
GISExtent Extent = new GISExtent(mfh.MinX, mfh.MaxX, mfh.MinY, mfh.MaxY); //地图范围extent
string layername = GISTools.ReadString(br); //读取图层名
List <GISField> Fields = ReadFields(br, mfh.FieldCount); //读取字段信息
GISLayer layer = new GISLayer(layername, ShapeType, Extent, Fields);
ReadFeatures(layer, br, mfh.FeatureCount);
br.Close();
fsr.Close();
return(layer);
}
private void btchangedotdensity_Click(object sender, EventArgs e)
{
int dotdensity = Convert.ToInt32(tbdotdensity.Text);
int dotsize = Convert.ToInt32(tbdotsize.Text);
Color dotcolor = btdotfillcolor.BackColor;
//获取归一化后的属性数据 作为每一个控件对象内点数量的权重
List <int> normalizations = layer.getNormalized(cbattributedot.SelectedIndex, dotdensity);
if (normalizations == null)
{
MessageBox.Show("基于该属性无法绘制点密度地图!!");
return;
}
//新建一个dotlayer，在点密度中的点将以一个点图层的形式显示出来
GISLayer dotlayer = new GISLayer("dotdensity", SHAPETYPE.point, layer.Extent);
dotlayer.Selectable = false; //设置为不可选择
dotlayer.ThematicType = THEMATICTYPE.DotDensity; //设置为点密度型专题地图
dotlayer.defaultThmatic = new GISThematic(dotcolor, dotsize, dotcolor);
List <GISFeature> dotpoints = GISTools.MakeRandomDensityDot(layer,
cbattributedot.SelectedIndex, normalizations);
dotlayer.Features = dotpoints;
//先移除之前已有的点密度图层
for (int i = Document.layers.Count - 1; i > 0; i--)
{
if (Document.layers[i].Name == "dotdensity")
{
Document.layers.RemoveAt(i);
}
}
Document.layers.Add(dotlayer);//将dotlayer添加到document中 在更新地图绘制时会自动绘制layers里面的所有图层
//更新地图绘制
if (sender.Equals(previewds))
{
PreviewWindow.UpdateMap();
}
else if (sender.Equals(btchangedotdensity))
{
Mapwindow.UpdateMap();
}
}
public override void draw(Graphics graphics, GISView view)
{
Point[] points = GISTools.GetScreenPoints(Vertexes, view);
graphics.FillPolygon(new SolidBrush(Color.Yellow), points);
graphics.DrawPolygon(new Pen(Color.White, 2), points);
}
public override void draw(Graphics graphics, GISView view)
{
Point[] points = GISTools.GetScreenPoints(Vertexes, view);
graphics.DrawLines(new Pen(Color.Red, 2), points);
}
//读取一个gisfeature的所有属性值，放在gisfile中 此函数需要事先知道字段结构，根据字段类型选取适当的读取函数
static GISAttribute ReadAttributes(List <GISField> fs, BinaryReader br)
{
GISAttribute attribute = new GISAttribute();
for (int i = 0; i < fs.Count; i++)
{
Type type = fs[i].datatype;
if (type.ToString() == "System.Boolean")
{
attribute.AddValue(br.ReadBoolean());
}
else if (type.ToString() == "System.Boolean")
{
attribute.AddValue(br.ReadBoolean());
}
else if (type.ToString() == "System.Byte")
{
attribute.AddValue(br.ReadByte());
}
else if (type.ToString() == "System.Char")
{
attribute.AddValue(br.ReadChar());
}
else if (type.ToString() == "System.Decimal")
{
attribute.AddValue(br.ReadDecimal());
}
else if (type.ToString() == "System.Double")
{
attribute.AddValue(br.ReadDouble());
}
else if (type.ToString() == "System.Single")
{
attribute.AddValue(br.ReadSingle());
}
else if (type.ToString() == "System.Int32")
{
attribute.AddValue(br.ReadInt32());
}
else if (type.ToString() == "System.Int64")
{
attribute.AddValue(br.ReadInt64());
}
else if (type.ToString() == "System.UInt16")
{
attribute.AddValue(br.ReadUInt16());
}
else if (type.ToString() == "System.UInt32")
{
attribute.AddValue(br.ReadUInt32());
}
else if (type.ToString() == "System.UInt64")
{
attribute.AddValue(br.ReadUInt64());
}
else if (type.ToString() == "System.Boolean")
{
attribute.AddValue(br.ReadBoolean());
}
else if (type.ToString() == "System.String")
{
attribute.AddValue(GISTools.ReadString(br));
}
}
return(attribute);
}
static void WriteAttributes(GISAttribute attribute, BinaryWriter bw)
{
for (int i = 0; i < attribute.ValueCount(); i++)
{
Type type = attribute.GetValue(i).GetType();
if (type.ToString() == "System.Boolean")
{
bw.Write((bool)attribute.GetValue(i));
}
else if (type.ToString() == "System.Byte")
{
bw.Write((byte)attribute.GetValue(i));
}
else if (type.ToString() == "System.Char")
{
bw.Write((char)attribute.GetValue(i));
}
else if (type.ToString() == "System.Decimal")
{
bw.Write((decimal)attribute.GetValue(i));
}
else if (type.ToString() == "System.Double")
{
bw.Write((double)attribute.GetValue(i));
}
else if (type.ToString() == "System.Single")
{
bw.Write((float)attribute.GetValue(i));
}
else if (type.ToString() == "System.Int32")
{
bw.Write((int)attribute.GetValue(i));
}
else if (type.ToString() == "System.Int64")
{
bw.Write((long)attribute.GetValue(i));
}
else if (type.ToString() == "System.UInt16")
{
bw.Write((ushort)attribute.GetValue(i));
}
else if (type.ToString() == "System.UInt32")
{
bw.Write((uint)attribute.GetValue(i));
}
else if (type.ToString() == "System.UInt64")
{
bw.Write((ulong)attribute.GetValue(i));
}
else if (type.ToString() == "System.SByte")
{
bw.Write((sbyte)attribute.GetValue(i));
}
else if (type.ToString() == "System.Int16")
{
bw.Write((short)attribute.GetValue(i));
}
else if (type.ToString() == "System.String")
{
GISTools.WriteString((string)attribute.GetValue(i), bw);
}
}
}
