private TileExtent getTileExtent_4490(int zoomLevel)
{
TileExtent tileExtent = new TileExtent();
tileExtent.ProjType = this.PROJECTION_TYPE;
tileExtent.ZoomLevel = zoomLevel;
tileExtent.ZoomResolution = this.GetZoomResolution(zoomLevel);
tileExtent.ZoomScale = this.GetZoomScale(zoomLevel);
tileExtent.MinColumnIndex = 0;
tileExtent.MinRowIndex = 0;
if (zoomLevel == 0)
{
tileExtent.RowNumber = 1;
tileExtent.ColumnNumber = 1;
}
else if (zoomLevel == 1)
{
tileExtent.RowNumber = 1;
tileExtent.ColumnNumber = 2;
tileExtent.MaxColumnIndex = 0;
tileExtent.MaxRowIndex = 0;
}
else
{
tileExtent.RowNumber = Convert.ToInt32(1 * Math.Pow(2, (zoomLevel - 1)));
tileExtent.ColumnNumber = Convert.ToInt32(2 * Math.Pow(2, (zoomLevel - 1)));
}
tileExtent.MaxColumnIndex = tileExtent.ColumnNumber - 1;
tileExtent.MaxRowIndex = tileExtent.RowNumber - 1;
return(tileExtent);
}
/// <summary>
/// 获取默认瓦片范围
/// </summary>
/// <param name="zoomLevel"></param>
/// <returns></returns>
public TileExtent GetDefaultTileExtent(int zoomLevel)
{
if (!this.CheckZoomLevel(zoomLevel))
{
return(null);
}
TileExtent result = null;
switch (this.PROJECTION_TYPE)
{
case ProjectionType.EPSG_3857:
result = this.getTileExtent_3857(zoomLevel);
break;
case ProjectionType.EPSG_4326:
result = this.getTileExtent_4326(zoomLevel);
break;
case ProjectionType.EPSG_4490:
result = this.getTileExtent_4490(zoomLevel);
break;
default:
result = null;
break;
}
return(result);
}
private TileExtent getTileExtent_3857(int zoomLevel)
{
TileExtent tileExtent = new TileExtent();
tileExtent.ProjType = this.PROJECTION_TYPE;
tileExtent.ZoomLevel = zoomLevel;
tileExtent.ZoomResolution = this.GetZoomResolution(zoomLevel);
tileExtent.ZoomScale = this.GetZoomScale(zoomLevel);
tileExtent.MinColumnIndex = 0;
tileExtent.MinRowIndex = 0;
tileExtent.RowNumber = Convert.ToInt32(Math.Pow(2, zoomLevel));
tileExtent.ColumnNumber = Convert.ToInt32(Math.Pow(2, zoomLevel));
tileExtent.MaxColumnIndex = tileExtent.ColumnNumber - 1;
tileExtent.MaxRowIndex = tileExtent.RowNumber - 1;
return(tileExtent);
}
