//导入.dem格式的文件
private bool ImportDEMFormat(string InFile, ref MapWinGIS.ICallback Callback)
{
Stream FileStream;
sDEMData DEMData = new sDEMData();
try
{
FileStream = System.IO.File.Open(InFile, FileMode.Open, FileAccess.Read);
if (!(FileStream == null))
{
DEMData = ReadDEMData(FileStream, Callback);
FileStream.Close();
FileStream.Dispose();
MakeGrid(DEMData, Callback);
return(true);
}
else
{
return(false);
}
}
catch (System.Exception ex)
{
MapWinGIS.Utility.Logger.Message("导入.dem格式的文件出现错误 " + InFile + "\r\n" + ex.Message);
return(false);
}
}
private void MakeGrid(sDEMData DEMData, MapWinGIS.ICallback Callback)
{
//根据.dem文件，生成一个网格文件对象
MapWinGIS.GridHeader h = new MapWinGIS.GridHeader();
int i;
int j;
int m;
int n;
h.dX = 30;
h.dY = 30;
h.Notes = "DEMData.Notes";
h.NodataValue = -1;
h.NumberCols = DEMData.NumCols;
h.NumberRows = System.Convert.ToInt32((DEMData.MaxY() - DEMData.MinY() / 30)) + 1;
h.XllCenter = DEMData.MinX();
h.YllCenter = DEMData.MinY();
MapWinGIS.Utility.Logger.Dbg("根据.dem文件和其数据文件，生成一个网格文件对象");
base.Close();
MapWinGIS.Utility.Logger.Dbg("开始创建");
base.CreateNew("", h, MapWinGIS.GridDataType.ShortDataType, h.NodataValue, true, MapWinGIS.GridFileType.Binary);
MapWinGIS.Utility.Logger.Dbg("只带header的新的grid网格文件创建了");
for (i = 0; i < DEMData.NumCols; i++)
{
for (j = 0; j < DEMData.NumElevs[i]; j++)
{
base.ProjToCell(DEMData.ColStarts[i].X, System.Convert.ToInt32(DEMData.ColStarts[i].Y) + (30 * j), out m, out n);
base.Value[m, n] = DEMData.Values[i, j];
}
MapWinGIS.Utility.Logger.Dbg("创建 MapWinGIS grid 对象. numCols: " + i.ToString());
if (Callback != null)
{
Callback.Progress(base.Key, 50 + i / DEMData.NumCols * 50, "创建 MapWinGIS grid 对象");
}
}
MapWinGIS.Utility.Logger.Dbg("生成一个网格文件对象完成");
}
private sDEMData ReadDEMData(Stream fileStream, MapWinGIS.ICallback Callback)
{
// 从USGS读取dem格式的数据文件(ASCII 文本)
int i, j;
int numElevs;
int Elev = 0;
int Off2;
int Off3;
int Inserts;
sDEMData DEMData = new sDEMData();
string chunckResult;
try
{
//获取header数据
DEMData.Notes = GetChunk(fileStream, 1, 144);
DEMData.HorizUnits = System.Convert.ToInt32(GetChunk(fileStream, 529, 6));
DEMData.VertUnits = System.Convert.ToInt32(GetChunk(fileStream, 535, 6));
DEMData.Vertices = new sVertex[4];
for (i = 0; i <= 3; i++)
{
DEMData.Vertices[i].X = Fdbl(GetChunk(fileStream, 547 + (48 * i), 24));
DEMData.Vertices[i].Y = Fdbl(GetChunk(fileStream, 571 + (48 * i), 24));
}
DEMData.Min = System.Convert.ToDouble(Fdbl(GetChunk(fileStream, 739, 24)));
DEMData.Max = System.Convert.ToDouble(Fdbl(GetChunk(fileStream, 763, 24)));
DEMData.NumCols = System.Convert.ToInt32((GetChunk(fileStream, 859, 6)));
DEMData.Values = new int[DEMData.NumCols - 1 + 1, 1];
DEMData.NumElevs = new int[DEMData.NumCols - 1 + 1];
MapWinGIS.Utility.Logger.Dbg("DEM 的头(Header)信息:");
MapWinGIS.Utility.Logger.Dbg("DEMData.Notes: " + DEMData.Notes);
MapWinGIS.Utility.Logger.Dbg("DEMData.HorizUnits: " + DEMData.HorizUnits.ToString());
MapWinGIS.Utility.Logger.Dbg("DEMData.VertUnits: " + DEMData.VertUnits.ToString());
MapWinGIS.Utility.Logger.Dbg("DEMData.Min: " + DEMData.Min.ToString());
MapWinGIS.Utility.Logger.Dbg("DEMData.Max: " + DEMData.Max.ToString());
MapWinGIS.Utility.Logger.Dbg("DEMData.NumCols: " + DEMData.NumCols.ToString());
//获取海拔(elevation)数据
Off2 = 1024;
Inserts = 0;
DEMData.ColStarts = new sVertex[DEMData.NumCols - 1 + 1];
MapWinGIS.Utility.Logger.Dbg("DEM Data");
for (i = 0; i < DEMData.NumCols; i++)
{
//读取elevs的数量, starting x 和 starting y
numElevs = Convert.ToInt32(GetChunk(fileStream, Off2 + 13, 6));
DEMData.NumElevs[i] = numElevs;
DEMData.ColStarts[i].X = Fdbl(GetChunk(fileStream, Off2 + 25, 24));
DEMData.ColStarts[i].Y = Fdbl(GetChunk(fileStream, Off2 + 49, 24));
//Information.UBound(DEMData.Values, 2)
if (numElevs - 1 > DEMData.Values.GetLength(1))
{
DEMData.Values = (int[, ])Microsoft.VisualBasic.CompilerServices.Utils.CopyArray((Array)DEMData.Values, new int[DEMData.NumCols, numElevs]);
}
for (j = 0; j < numElevs; j++)
{
Inserts = 0;
if (j > 145)
{
Inserts = (int)((j - 145) / 171 + 1);
}
Off3 = Off2 + 145 + (j * 6) + Inserts * 4; //4 spaces between each extended group
chunckResult = GetChunk(fileStream, Off3, 6);
if (chunckResult.Trim() != string.Empty)
{
if (int.TryParse(chunckResult, out Elev) == false)
{
Elev = -1;
MapWinGIS.Utility.Logger.Dbg("ReadDEMData Error. GetChunk returned non-integer:" + chunckResult);
}
}
DEMData.Values[i, j] = Elev;
}
if (numElevs <= 146)
{
Off2 = Off2 + 1024;
}
else
{
Inserts = (int)((numElevs - 146) / 170 + 1);
Off2 = Off2 + 1024 + Inserts * 1024;
}
if (Callback != null)
{
Callback.Progress(base.Key, i / DEMData.NumCols * 50, "读取 DEM 数据");
}
}
MapWinGIS.Utility.Logger.Dbg("读取 DEM 数据完成");
return(DEMData);
}
catch (System.Exception ex)
{
MapWinGIS.Utility.Logger.Msg("读取DEM数据出错 : " + ex.Message);
}
sDEMData a = new sDEMData();
return(a);
}