Outputting from an custom geoprocessing tool (IGPFunction)

GuénoléChoné — Tue, 11 Jun 2013 21:56:14 GMT

Hi,

I'm creating a custom geoprocessing tool in C# (implementing IGPFunction2), and I cannot succeed in creating the output of the gp tool (in my case, a point feature class, but the kind of output I try to create doesn't really matter, it could be a simple table or even a raster...). I guess I need to start by creating the IGPValue (same thing than for the tool's inputs), like that:

public void Execute(IArray paramvalues, ITrackCancel trackcancel, IGPEnvironmentManager envMgr, IGPMessages message)
{
[...]
IGPValue gp_output = m_GPUtilities.UnpackGPValue((IGPParameter3)paramvalues.get_Element(3));

Than what should I do ? How to create a empty (to begin with...) feature class from this IGPValue ?

Re: Outputting from an custom geoprocessing tool (IGPFunction)

TimSexton1 — Thu, 23 Oct 2014 21:03:04 GMT

You have to define an output parameter in the ParameterInfo array of your GP tool, then set the value of that output parameter in the Execute() method. I've included a small code sample below:

// This is the location where the parameters to the Function Tool are defined.

// This property returns an IArray of parameter objects (IGPParameter).

// These objects define the characteristics of the input and output parameters.

public IArray ParameterInfo

{

get

{

//Array to the hold the parameters

IArray parameters = new ArrayClass();

//Input DataType is GPStringType

IGPParameterEdit3 inputParameter = new GPParameterClass();

inputParameter.DataType = new GPStringTypeClass();

// Default Value object is GPString

inputParameter.Value = new GPStringClass();

// Set Input Parameter properties

inputParameter.Direction = esriGPParameterDirection.esriGPParameterDirectionInput;

inputParameter.DisplayName = "Station ID";

inputParameter.Name = "stationid";

inputParameter.ParameterType = esriGPParameterType.esriGPParameterTypeRequired;

parameters.Add(inputParameter);

//Out DataType is GPStringType

IGPParameterEdit3 outputParameter = new GPParameterClass();

outputParameter.DataType = new GPStringTypeClass();

// Default Value object is GPString

outputParameter.Value = new GPStringClass();

// Set Output Parameter properties

outputParameter.Direction = esriGPParameterDirection.esriGPParameterDirectionOutput;

outputParameter.DisplayName = "Output";

outputParameter.Name = "output";

outputParameter.ParameterType = esriGPParameterType.esriGPParameterTypeDerived;

parameters.Add(outputParameter);

return parameters;

}

... and then

// Execute: Execute the function given the array of the parameters

public void Execute(IArray paramvalues, ITrackCancel trackcancel, IGPEnvironmentManager envMgr, IGPMessages message)

{

bool success = false;

// Get the first Input Parameter

IGPParameter inputParameter = (IGPParameter)paramvalues.get_Element(0);

// UnPackGPValue. This ensures you get the value either form the dataelement or GpVariable (ModelBuilder)

IGPValue inputValue = m_GPUtilities.UnpackGPValue(inputParameter);

// input station ID

string inputStringValue = inputValue.GetAsText();

if (!string.IsNullOrEmpty(inputStringValue))

success = true;

if (!success)

message.AddError(2, "An error occurred during the test.");

else

{

message.AddMessage("Test completed successfully!");

}

// Set the Output Parameter

IGPParameter outputParameter = (IGPParameter)paramvalues.get_Element(1);

IGPString outValue = new GPStringClass();

outValue.Value = "This is my output showing input value of '" + inputStringValue + "'";

m_GPUtilities.PackGPValue((IGPValue)outValue, outputParameter);

}

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Outputting from an custom geoprocessing tool (IGPFunction)

Re: Outputting from an custom geoprocessing tool (IGPFunction)