arcgis arcengine Using environment settings

In this topic

• About using environment settings
• Environment settings summary table

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About using environment settings

Each tool has a set of parameters it uses to execute an operation. Some of these parameters are common among all tools, such as a tolerance or output location. These parameters can obtain their default values from a geoprocessing environment that all tools utilize during their operation.

When a tool is executed, the current environment settings can also be used as global input parameter values. Settings, such as an area of interest (extent), the coordinate system of the output dataset, and the cell size of a new raster dataset, can all be specified in the geoprocessing environments.

In a program, the geoprocessor object possesses all default environment values. You can get the default value or change it. The environment values remain in effect within the current geoprocessing session. The following table shows the environment methods the geoprocessor has to work with:

Method	Description
GetEnvironmentValue(envName)	Retrieves the value of an environment by name.
SetEnvironmentValue(envName, envValue)	Updates the value of an environment by name.
ResetEnvironments()	Resets the environments to their default state.
ListEnvironments("*")	Returns the list of environments (properties).
SaveSettings(sFileName)	Saves the current settings (toolboxes, environments, and so on) to a file on disk in Extensible Markup Language (XML) format.
LoadSettings(sFileName)	Loads the current settings from the saved file.

All environment names are passed as strings. Environment names are not case sensitive; therefore, it does not matter if "workspace" or "Workspace" is used.

The following is a code example to set environment values. By default, the output of Copy Features geoprocessing tool gets the coordinate system of the input. By setting a different value, you override the default coordinate system.

[C#]

public void setCoordinateSystem(IGeoProcessor2 gp)
{
    // Set overwrite option to true.
    gp.OverwriteOutput = true;

    // Set workspace environment.
    gp.SetEnvironmentValue("workspace", @"C:\data\saltlake.gdb");

    // Set the output coordinate system environment.            
    gp.SetEnvironmentValue("outputCoordinateSystem", @
        "C:\Program Files\ArcGIS\Desktop10.0\Coordinate Systems\Projected Coordinate Systems\UTM\Nad 1983\NAD 1983 UTM Zone 12N.prj");

    IVariantArray parameters = new VarArrayClass();
    parameters.Add("roads");
    parameters.Add("roads_copy");

    gp.Execute("CopyFeatures_management", parameters, null);
}

[VB.NET]

Public Sub setCoordinateSystem(ByVal gp As IGeoProcessor2)
    
    'Set overwrite option to true.
    gp.OverwriteOutput = True
    
    'Set workspace environment.
    gp.SetEnvironmentValue("workspace", "C:\data\saltlake.gdb")
    
    'Set the output coordinate system environment.
    gp.SetEnvironmentValue("outputCoordinateSystem", "C:\Program Files\ArcGIS\Desktop10.0\Coordinate Systems\Projected Coordinate Systems\UTM\Nad 1983\NAD 1983 UTM Zone 12N.prj")
    
    Dim parameters As IVariantArray = New VarArray
    parameters.Add("roads")
    parameters.Add("roads_copy")
    
    gp.Execute("CopyFeatures_management", parameters, Nothing)
    
End Sub

The following code example shows how to retrieve and reset environment values:

[C#]

// Get the cell size environment value.
object env = gp.GetEnvironmentValue("cellsize");

// Reset the environment values to their defaults.
gp.ResetEnvironments();

[VB.NET]

' Get the cell size environment value.
Dim env As Object = GP.GetEnvironmentValue("cellsize")

' Reset the environment values to their defaults.
GP.ResetEnvironments()

The ListEnvironments method returns a list of environments. This method has a wildcard option, and returns an IGpEnumList of strings that can be looped through. The following code example shows how to list environments. The method returns all environments that start with the letter "q" (for example, qualifedFieldNames).

[C#]

public void ListGeoprocessingEnvironments(IGeoprocessor2 gp)
{
    // List all environments that start with the letter q.
    IGpEnumList environments = gp.ListEnvironments("q*");

    // Only one environment starts with q (qualifiedFieldNames).
    string env = environments.Next();
    Console.WriteLine(env);

}

[VB.NET]

Public Sub ListGeoprocessingEnvironments(ByVal gp As IGeoProcessor2)
    
    'List all environments that start with the letter q.
    Dim environments As IGpEnumList = gp.ListEnvironments("q*")
    
    Dim env As String = environments.Next()
    
    'Only one environment starts with q (qualifiedFieldNames).
    Console.WriteLine(env)
    env = environments.Next()
    
End Sub

After setting several environments using the SetEnvironmentValue method, you can save them to an XML file, then use them later by loading the settings with the LoadSettings method as shown in the following code example:

[C#]

public void SaveLoadSettings(IGeoProcessor2 gp)
{
    gp.SetEnvironmentValue("workspace", @"C:/data/mydata.gdb");
    gp.SetEnvironmentValue("extent", "-3532000, -911000, -3515000, -890000");
    gp.SetEnvironmentValue("outputCoordinateSystem", 
        "PROJCS['NAD_1983_UTM_Zone_11N',GEOGCS['GCS_North_American_1983',DATUM['D_North_American_1983',SPHEROID['GRS_1980',6378137.0,298.257222101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]],PROJECTION['Transverse_Mercator'],PARAMETER['False_Easting',500000.0],PARAMETER['False_Northing',0.0],PARAMETER['Central_Meridian',-117.0],PARAMETER['Scale_Factor',0.9996],PARAMETER['Latitude_Of_Origin',0.0],UNIT['Meter',1.0]]");

    // Save environment settings to an XML file.
    string settingsFile = @"C:\sdk\MyCustomSettings.xml";
    gp.SaveSettings(settingsFile);

    // Load previously saved environment settings.
    gp.LoadSettings(settingsFile);
    object sExtent = gp.GetEnvironmentValue("workspace");
}

[VB.NET]

Public Sub SaveLoadSettings(ByVal gp As IGeoProcessor2)
    
    gp.SetEnvironmentValue("workspace", "C:/data/mydata.gdb")
    gp.SetEnvironmentValue("extent", "-3532000, -911000, -3515000, -890000")
    gp.SetEnvironmentValue("outputCoordinateSystem", "PROJCS['NAD_1983_UTM_Zone_11N',GEOGCS['GCS_North_American_1983',DATUM['D_North_American_1983',SPHEROID['GRS_1980',6378137.0,298.257222101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]],PROJECTION['Transverse_Mercator'],PARAMETER['False_Easting',500000.0],PARAMETER['False_Northing',0.0],PARAMETER['Central_Meridian',-117.0],PARAMETER['Scale_Factor',0.9996],PARAMETER['Latitude_Of_Origin',0.0],UNIT['Meter',1.0]]")
    
    ' Save environment settings to an XML file.
    Dim settingsFile As String = "C:\sdk\MyCustomSettings.xml"
    gp.SaveSettings(settingsFile)
    
    ' Load previously saved environment settings.
    gp.LoadSettings(settingsFile)
    Dim sExtent As Object = gp.GetEnvironmentValue("workspace")
    
End Sub

Environment settings summary table

The following table shows the geoprocessing environments in alphabetical order. The first column in the table is the name of the environment. You must pass this name as a string to the geoprocessor's GetEnvironmentValue and SetEnvironmentValue methods. The second column is the display name as shown on the Environment Settings dialog box.

Each environment display name in the table links to the reference page of that environment, which explains what the environment is for and what values can be set for it.

Environment names are not case-sensitive in .NET.

Environment name	Display name
autoCommit	Auto Commit
cartographicCoordinateSystem	Cartographic Coordinate System
cellSize	Cell size
coincidentPoints	Coincident points
compression	Compression
configKeyword	Output CONFIG Keyword
derivedPrecision	Precision For Derived Coverages
extent	Extent
geographicTransformations	Geographic Transformations
maintainSpatialIndex	Maintain Spatial Index
mask	Mask
MDomain	Output M Domain
MResolution	M Resolution
MTolerance	M Tolerance
newPrecision	Precision For New Coverages
outputCoordinateSystem	Output Coordinate System
outputMFlag	Output has M Values
outputZFlag	Output has Z values
outputZValue	Default output Z value
projectCompare	Level Of Comparison Between Projection Files
pyramid	Pyramid
qualifiedFieldNames	Maintain fully qualified field names
randomGenerator	Random number generator
rasterStatistics	Raster statistics
referenceScale	Reference Scale
scratchWorkspace	Scratch Workspace
snapRaster	Snap Raster
spatialGrid1, 2, 3	Output Spatial Grid 1, 2, 3
terrainMemoryUsage	Terrain Memory Usage
tileSize	Tile size
tinSaveVersion	TIN storage version
workspace	Current Workspace
XYDomain	Output XY Domain
XYResolution	XY Resolution
XYTolerance	XY Tolerance
ZDomain	Output Z Domain
ZResolution	Z Resolution
ZTolerance	Z Tolerance

See Also:

What is a geoprocessing environment?
A quick tour of geoprocessing environments

 

 

作者： cglnet

出处： http://www.cnblogs.com/cglnet

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