private async void ExecuteStatisticsQuery(object sender, EventArgs e)
{
// Remove the placeholder "Add statistic" row (if it exists).
StatisticDefinition placeholderRow = _statisticDefinitions.LastOrDefault();
if (placeholderRow != null && placeholderRow.OutputAlias == "")
{
_statisticDefinitions.Remove(placeholderRow);
}
// Verify that there is at least one statistic definition.
if (!_statisticDefinitions.Any())
{
ShowAlert("Statistical Query", "Please define at least one statistic for the query.");
return;
}
// Create the statistics query parameters, pass in the list of statistic definitions.
StatisticsQueryParameters statQueryParams = new StatisticsQueryParameters(_statisticDefinitions);
// Specify the selected group fields (if any).
if (_groupByFields != null)
{
foreach (KeyValuePair <string, bool> groupField in _groupByFields.Where(field => field.Value))
{
statQueryParams.GroupByFieldNames.Add(groupField.Key);
}
}
// Specify the fields to order by (if any).
if (_orderByFields != null)
{
foreach (OrderFieldOption orderBy in _orderByFields)
{
statQueryParams.OrderByFields.Add(orderBy.OrderInfo);
}
}
// Ignore counties with missing data
statQueryParams.WhereClause = "\"State\" IS NOT NULL";
// Execute the statistical query with these parameters and await the results.
try
{
StatisticsQueryResult statQueryResult = await _usStatesTable.QueryStatisticsAsync(statQueryParams);
// Get results formatted as a dictionary (group names and their associated dictionary of results).
Dictionary <string, IReadOnlyDictionary <string, object> > resultsLookup = statQueryResult.ToDictionary(result => string.Join(", ", result.Group.Values), result => result.Statistics);
// Create an instance of a custom data source to display the results.
StatisticQueryResultsDataSource statResultsDataSource = new StatisticQueryResultsDataSource(resultsLookup);
// Create a new table with a grouped style for displaying rows.
UITableViewController statResultsTable = new UITableViewController(UITableViewStyle.Grouped)
{
// Set the table view data source.
TableView = { Source = statResultsDataSource }
};
// Show the table view.
NavigationController.PushViewController(statResultsTable, true);
}
catch (ArcGISWebException exception)
{
ShowAlert("There was a problem performing the query.", exception.ToString());
}
}
private async void ExecuteStatisticsQuery(object sender, EventArgs e)
{
// Verify that there is at least one statistic definition
if (!_statisticDefinitions.Any())
{
// Warn the user to define a statistic to query
ShowMessage("Please define at least one statistic for the query.", "Statistical Query");
return;
}
// Create the statistics query parameters, pass in the list of statistic definitions
StatisticsQueryParameters statQueryParams = new StatisticsQueryParameters(_statisticDefinitions);
// Specify the selected group fields (if any)
if (_groupByFields != null)
{
// Find fields in the dictionary with a 'true' value and add them to the group by field names
foreach (KeyValuePair <string, bool> groupField in _groupByFields.Where(field => field.Value))
{
statQueryParams.GroupByFieldNames.Add(groupField.Key);
}
}
// Specify the fields to order by (if any)
if (_orderByFields != null)
{
foreach (OrderFieldOption orderBy in _orderByFields)
{
statQueryParams.OrderByFields.Add(orderBy.OrderInfo);
}
}
// Ignore counties with missing data
statQueryParams.WhereClause = "\"State\" IS NOT NULL";
try
{
// Execute the statistical query with these parameters and await the results
StatisticsQueryResult statQueryResult = await _usStatesTable.QueryStatisticsAsync(statQueryParams);
// Get results formatted as a dictionary (group names and their associated dictionary of results)
Dictionary <string, IReadOnlyDictionary <string, object> > resultsLookup = statQueryResult.ToDictionary(r => string.Join(", ", r.Group.Values), r => r.Statistics);
// Create an instance of a custom list adapter that has logic to show results as expandable groups
ExpandableResultsListAdapter expandableListAdapter = new ExpandableResultsListAdapter(this, resultsLookup);
// Create an expandable list view and assign the expandable adapter
ExpandableListView expandableResultsListView = new ExpandableListView(this);
expandableResultsListView.SetAdapter(expandableListAdapter);
// Show the expandable list view in a dialog
AlertDialog.Builder dialogBuilder = new AlertDialog.Builder(this);
dialogBuilder.SetView(expandableResultsListView);
dialogBuilder.Show();
}
catch (Exception ex)
{
new AlertDialog.Builder(this).SetMessage(ex.ToString()).SetTitle("Error").Show();
}
}