private void btnQuant_Click(object sender, EventArgs e)
{
//Create a new instance for MapWinGIS.Table
MapWinGIS.Table myTable = new MapWinGIS.Table();
//Define the data source of Table instance
myTable.Open(@"D:\GISSampleData2\arabcntry.dbf", null);
//Define the index of the field will used in symbology
int myFieldIndex = 1;
//Get the number of rows in the table
int numberOfRows = myTable.NumRows;
//Create an array to store the cell values of the field
double[] myCellsValues = new double[numberOfRows];
//Populate the array with cell values restored from the Table instance
for (int i = 0; i < numberOfRows - 1; i++)
{
myCellsValues[i] =
System.Convert.ToDouble(myTable.get_CellValue(1, i));
}
//Get the minimum and maximum values
double minValue = myCellsValues.Min();
double maxValue = myCellsValues.Max();
//Create a new instance for MapWinGIS.ShapefileColorScheme
MapWinGIS.ShapefileColorScheme myScheme = new MapWinGIS.ShapefileColorScheme();
//Set the layer handler to the MapWinGIS.ShapefileColorScheme instance
myScheme.LayerHandle = intHandler;
//Set the field index to use in symbology
myScheme.FieldIndex = myFieldIndex;
//Create a new instance for MapWinGIS.ShapefileColorBreak
MapWinGIS.ShapefileColorBreak myBreak = new MapWinGIS.ShapefileColorBreak();
//Set the minimum value in the field as a start value
myBreak.StartValue = minValue;
//Set the start color of the scheme
myBreak.StartColor =
(UInt32)(System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Aqua));
//Set the maximum value in the field as an end value
myBreak.EndValue = maxValue;
//Set the end color of the sceme
myBreak.EndColor =
(UInt32)(System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.DarkBlue));
//Add the break to the color scheme
myScheme.Add(myBreak);
//Upgrade display using the scheme
axMap1.ApplyLegendColors(myScheme);
}
/// <summary>
/// 打开指定数据源的图层
/// </summary>
/// <param name="filename">文件名</param>
/// <param name="callback"></param>
/// <returns></returns>
public bool Open(string filename, MapWinGIS.ICallback callback)
{
this.Close();
if (filename.ToLower().EndsWith(".shp"))
{
MapWinGIS.Shapefile sf = new MapWinGIS.Shapefile();
if (sf.Open(filename, callback))
{
// 检查dbf是否存在
bool error = false;
if (!File.Exists(Path.ChangeExtension(sf.Filename, ".dbf")))
{
m_error = LayerSourceError.DbfIsMissing;
error = true;
}
// 检查DBF记录数相匹配的形状的数量。
MapWinGIS.Table table = new MapWinGIS.Table();
table.Open(Path.ChangeExtension(sf.Filename, ".dbf"), null);
if (sf.NumShapes != table.NumRows)
{
m_error = LayerSourceError.DbfRecordCountMismatch;
error = true;
}
table.Close();
if (error)
{
sf.Close();
}
else
{
m_shapefile = sf;
}
return(!error);
}
else
{
m_error = LayerSourceError.OcxBased;
m_ErrorString = sf.get_ErrorMsg(sf.LastErrorCode);
}
}
else
{
bool asGrid = true;
if (filename.ToLower().EndsWith(".tif"))
{
asGrid = false;
}
// TODO: 可能更聪明的选择是在grid/image中使用应用程序设置
if (asGrid)
{
MapWinGIS.Grid grid = new MapWinGIS.Grid();
if (grid.Open(filename, MapWinGIS.GridDataType.UnknownDataType, false, MapWinGIS.GridFileType.UseExtension, callback))
{
m_grid = grid;
return(true);
}
}
// 尝试image
MapWinGIS.Image image = new MapWinGIS.Image();
if (image.Open(filename, MapWinGIS.ImageType.USE_FILE_EXTENSION, false, callback))
{
m_image = image;
return(true);
}
else
{
m_error = LayerSourceError.OcxBased;
m_ErrorString = image.get_ErrorMsg(image.LastErrorCode);
}
}
return(false);
}