/// <summary>
/// 返回最后错误代码的描述
/// </summary>
public string GetErrorMessage()
{
string s = "";
switch (m_error)
{
case LayerSourceError.DbfIsMissing:
s = "Dbf table丢失";
break;
case LayerSourceError.DbfRecordCountMismatch:
s = "DBF表的行数是不同的形状";
break;
case LayerSourceError.OcxBased:
s = m_ErrorString;
break;
}
m_ErrorString = "";
m_error = LayerSourceError.None;
return(s);
}
/// <summary>
/// 关闭图层. 设置未定义的图层类型
/// </summary>
public void Close()
{
m_error = LayerSourceError.None;
switch (this.Type)
{
case LayerSourceType.Shapefile:
m_shapefile.Close();
m_shapefile = null;
break;
case LayerSourceType.Image:
m_image.Close();
m_image = null;
break;
case LayerSourceType.Grid:
m_grid.Close();
m_grid = null;
break;
default:
break;
}
}
/// <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);
}
