/// <summary>
/// Handles the click event of the Button and starts asynchronous geoprocessing.
/// </summary>
private void btnRunGP_Click(object sender, EventArgs e)
{
try
{
#region tidy up any previous gp runs
//Clear the ListView control
listView1.Items.Clear();
//Remove any result layers present in the map
IMapLayers mapLayers = axMapControl1.Map as IMapLayers;
foreach (IFeatureLayer resultLayer in _resultsList)
{
mapLayers.DeleteLayer(resultLayer);
}
axTOCControl1.Update();
//Empty the results layer list
_resultsList.Clear();
//make sure that my GP tool queue is empty
_myGPToolsToExecute.Clear();
#endregion
//Buffer the selected cities by the specified distance
ESRI.ArcGIS.AnalysisTools.Buffer bufferTool = new ESRI.ArcGIS.AnalysisTools.Buffer();
bufferTool.in_features = _layersDict["Cities"];
bufferTool.buffer_distance_or_field = txtBufferDistance.Text + " Miles";
bufferTool.out_feature_class = "city_buffer.shp";
//Clip the zip codes layer with the result of the buffer tool
ESRI.ArcGIS.AnalysisTools.Clip clipTool = new ESRI.ArcGIS.AnalysisTools.Clip();
clipTool.in_features = _layersDict["ZipCodes"];
clipTool.clip_features = bufferTool.out_feature_class;
clipTool.out_feature_class = "city_buffer_clip.shp";
//To run multiple GP tools asynchronously, all tool inputs must exist before ExecuteAsync is called.
//The output from the first buffer operation is used as an input to the second clip
//operation. To deal with this restriction a Queue is created and all tools added to it. The first tool
//is executed from this method, whereas the second is executed from the ToolExecuted event. This approach
//is scalable - any additional geoprocessing tools added to this queue will also be executed in turn.
_myGPToolsToExecute.Enqueue(bufferTool);
_myGPToolsToExecute.Enqueue(clipTool);
_gp.ExecuteAsync(_myGPToolsToExecute.Dequeue());
}
catch (Exception ex)
{
listView1.Items.Add(new ListViewItem(new string[2] {
"N/A", ex.Message
}, "error"));
}
}