Create buffer around selected points and add to a new shapefile

Question

I am trying to figure out how to create a buffer around selected points and add them to an new shapefile.

My idea is to have a loop that loops through the selected points and perform a buffer and then adds them to a new shapefile and saves it.

So here is my code to create points and feature data and saves it as a shapefile.

Here is my code for the shapefile creation:

public void addDataToMap(string folder, string shapefilename) {
        pMap = mDoc.FocusMap;

        string strFolder = folder;
        string strName = shapefilename;
        string strShapeFileName = "Shape";
        string strLatitude = "Latitude";
        string strLongitude = "Longitude";
        string strLocationName = "Name";

        IFeatureWorkspace pFWS;
        IWorkspaceFactory pWorkspaceFactory;
        pWorkspaceFactory = new ShapefileWorkspaceFactory();
        pFWS = (IFeatureWorkspace)pWorkspaceFactory.OpenFromFile(strFolder, 0);

        //FIELDS SETUP
        IFields pFields;
        IFieldsEdit pFieldsEdit;
        pFields = new Fields();
        pFieldsEdit = (IFieldsEdit)pFields;

        //FIELD1 SETUP
        IField pField;
        IFieldEdit pFieldEdit;
        pField = new Field();
        pFieldEdit = (IFieldEdit)pField;

        pFieldEdit.Name_2 = strShapeFileName;
        pFieldEdit.Type_2 = esriFieldType.esriFieldTypeGeometry;
        pFieldsEdit.AddField(pField);

        //FIELD2 SETUP
        IField pField1;
        IFieldEdit pFieldEdit1;
        pField1 = new Field();
        pFieldEdit1 = (IFieldEdit)pField1;

        pFieldEdit1.Name_2 = strLatitude;
        pFieldEdit1.Type_2 = esriFieldType.esriFieldTypeDouble;
        pFieldsEdit.AddField(pField1);

        //FIELD3 SETUP
        IField pField2;
        IFieldEdit pFieldEdit2;
        pField2 = new Field();
        pFieldEdit2 = (IFieldEdit)pField2;

        pFieldEdit2.Name_2 = strLongitude;
        pFieldEdit2.Type_2 = esriFieldType.esriFieldTypeDouble;
        pFieldsEdit.AddField(pField2);

        //FIELD4 SETUP
        IField pField3;
        IFieldEdit pFieldEdit3;
        pField3 = new Field();
        pFieldEdit3 = (IFieldEdit)pField3;

        pFieldEdit3.Name_2 = strLocationName;
        pFieldEdit3.Type_2 = esriFieldType.esriFieldTypeString;
        pFieldsEdit.AddField(pField3);

        IGeometryDef pGeomDef;
        IGeometryDefEdit pGeomDefEdit;
        pGeomDef = new GeometryDefClass();
        pGeomDefEdit = (IGeometryDefEdit)pGeomDef;
        pGeomDefEdit.GeometryType_2 = esriGeometryType.esriGeometryPoint;

        //Spatialreference setup
        ISpatialReferenceFactory SRF = new SpatialReferenceEnvironmentClass();
        ISpatialReference SR = SRF.CreateProjectedCoordinateSystem((int)esriSRProjCSType.esriSRProjCS_World_Mercator);
        SR = SRF.CreateGeographicCoordinateSystem((int)esriSRGeoCSType.esriSRGeoCS_WGS1984);
        ISpatialReferenceResolution SRR = (ISpatialReferenceResolution)SR;
        SRR.ConstructFromHorizon();
        ISpatialReferenceTolerance SRT = (ISpatialReferenceTolerance)SR;
        SRT.SetDefaultXYTolerance();
        pGeomDefEdit.SpatialReference_2 = SR;

        pFieldEdit.GeometryDef_2 = pGeomDef;

        IFeatureClass pFeatClass;
        pFeatClass = pFWS.CreateFeatureClass(strName, pFields, null, null, esriFeatureType.esriFTSimple, strShapeFileName, "");

        IFeatureLayer pFeaturelayer = new FeatureLayerClass();
        pFeaturelayer.FeatureClass = pFeatClass;
        pFeaturelayer.Name = pFeatClass.AliasName;

        IPoint point = new Point();
        for (int i = 1; i < data_.Count; i++)
        {

            point.PutCoords(data_[i].getLngAsDouble(), data_[i].getLatgAsDouble());

            IFeature feature = pFeatClass.CreateFeature();
            feature.Value[2] = data_[i].getLatgAsDouble();
            feature.Value[3] = data_[i].getLngAsDouble();
            feature.Value[4] = data_[i].getName();
            feature.Shape = point;
            feature.Store();
        }
        pMap.AddLayer(pFeaturelayer);
        mDoc.UpdateContents();
        mDoc.ActiveView.Refresh();
    }

And now when the layer is created I have done some code to Count the selected features and the if it is a Point I want to create a new shapefile with a given buffer around the selected points.

And here is that code:

        private void cmdBuffer_Click(object sender, EventArgs e)
        {
        int counter=0;
        IEnumFeature enumFeature = (IEnumFeature)ArcMap.Document.FocusMap.FeatureSelection;
        IFeature feature = enumFeature.Next();
        while (feature != null) {
            IGeometry geomfeature = feature.ShapeCopy;
            if (geomfeature.GeometryType == esriGeometryType.esriGeometryPoint)
            {
                //Create some buffering magic.
            }
            feature = enumFeature.Next();
        }
        if (counter != 0)
        {

        }
        else {
            MessageBox.Show("You need to select features to make a buffer", "Try again.");
        }
    }

Does anyone have a good practice for this?

Answer 1

Here is some code using VBA showing you an approach to calling the Buffer tool:

Public Sub buff()
    ' Get featurelayer so selections are used
    Dim pmxd As IMxDocument
    Set pmxd = ThisDocument
    Dim pmap As IMap
    Set pmap = pmxd.FocusMap
    Dim pl As ILayer
    Set pl = pmap.Layer(0)
    Dim pfl As IFeatureLayer
    Set pfl = pl

    ' Load parameters into Array, IMPORTANT must be same order as tool
    Dim pA As IVariantArray
    Set pA = New VarArray
    With pA
        .Add pfl
        .Add "IN_MEMORY/test"
        .Add "100 Meters" ' 100m
        .Add "FULL"
        .Add "ROUND"
        .Add "NONE"
        .Add "#" ' Default
        .Add "#" ' Default
    End With

    ' Create geoprocessor
    Dim pGP As IGeoProcessor
    Set pGP = New GeoProcessor
    pGP.AddOutputsToMap = True
    pGP.OverwriteOutput = True

    ' Run tool
    Dim pRes As IGeoProcessorResult
    Set pRes = pGP.Execute("Buffer_analysis", pA, Nothing)
    If pRes.Status <> esriJobSucceeded Then
        Debug.Print "oops something went wrong!"
    End If
End Sub