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();
}
}
// Execute a statistical query using the parameters defined by the user and display the results
private async void OnExecuteStatisticsQueryClicked(object sender, RoutedEventArgs e)
{
// Verify that there is at least one statistic definition
if (_statDefinitions.Count == 0)
{
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(_statDefinitions);
// Specify the group fields (if any)
foreach (string groupField in _groupByFields)
{
statQueryParams.GroupByFieldNames.Add(groupField);
}
// Specify the fields to order by (if any)
foreach (OrderFieldOption orderBy in _orderByFields)
{
statQueryParams.OrderByFields.Add(orderBy.OrderInfo);
}
// Execute the statistical query with these parameters and await the results
StatisticsQueryResult statQueryResult = await _usStatesTable.QueryStatisticsAsync(statQueryParams);
// Format the output for display of grouped results in the list view
IEnumerable <IGrouping <string, IReadOnlyDictionary <string, object> > > groupedResults = statQueryResult.GroupBy(r => string.Join(", ", r.Group.Values), r => r.Statistics);
// Apply the results to the list view data source
GroupedResultData.Source = groupedResults;
}
// Execute a statistical query using the parameters defined by the user and display the results
private async void OnExecuteStatisticsQueryClicked(object sender, EventArgs e)
{
// Verify that there is at least one statistic definition
if (!_statDefinitions.Any())
{
await((Page)Parent).DisplayAlert("Please define at least one statistic for the query.", "Statistical Query", "OK");
return;
}
// Create the statistics query parameters, pass in the list of statistic definitions
StatisticsQueryParameters statQueryParams = new StatisticsQueryParameters(_statDefinitions);
// Specify the group fields (if any)
foreach (string groupField in _groupByFields)
{
statQueryParams.GroupByFieldNames.Add(groupField);
}
// Specify the fields to order by (if any)
foreach (OrderFieldOption orderBy in _orderByFields)
{
statQueryParams.OrderByFields.Add(orderBy.OrderInfo);
}
// Execute the statistical query with these parameters and await the results
StatisticsQueryResult statQueryResult = await _usStatesTable.QueryStatisticsAsync(statQueryParams);
// Get results formatted as a lookup (list of group names and their associated dictionary of results)
ILookup <string, IReadOnlyDictionary <string, object> > resultsLookup = statQueryResult.ToLookup(result => string.Join(", ", result.Group.Values), result => result.Statistics);
// Loop through the formatted results and build a list of classes to display as grouped results in the list view
ObservableCollection <ResultGroup> resultsGroupCollection = new ObservableCollection <ResultGroup>();
foreach (IGrouping <string, IReadOnlyDictionary <string, object> > group in resultsLookup)
{
// Create a new group
ResultGroup resultGroup = new ResultGroup()
{
GroupName = group.Key
};
// Loop through all the results for this group and add them to the collection
foreach (IReadOnlyDictionary <string, object> resultSet in group)
{
foreach (KeyValuePair <string, object> result in resultSet)
{
resultGroup.Add(new StatisticResult {
FieldName = result.Key, StatValue = result.Value
});
}
}
// Add the group of results to the collection
resultsGroupCollection.Add(resultGroup);
}
// Apply the results to the list view data source and show the results grid
StatResultsList.ItemsSource = resultsGroupCollection;
ResultsGrid.IsVisible = true;
}
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.Count() == 0)
{
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 == true))
{
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);
}
}
// 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(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
statResultsTable.TableView.Source = statResultsDataSource;
// Show the table view
this.NavigationController.PushViewController(statResultsTable, true);
}
private async void OnExecuteStatisticsQueryClicked(object sender, EventArgs e)
{
// Create definitions for each statistic to calculate
StatisticDefinition statDefinitionAvgPop = new StatisticDefinition("POP", StatisticType.Average, "");
StatisticDefinition statDefinitionMinPop = new StatisticDefinition("POP", StatisticType.Minimum, "");
StatisticDefinition statDefinitionMaxPop = new StatisticDefinition("POP", StatisticType.Maximum, "");
StatisticDefinition statDefinitionSumPop = new StatisticDefinition("POP", StatisticType.Sum, "");
StatisticDefinition statDefinitionStdDevPop = new StatisticDefinition("POP", StatisticType.StandardDeviation, "");
StatisticDefinition statDefinitionVarPop = new StatisticDefinition("POP", StatisticType.Variance, "");
// Create a definition for count that includes an alias for the output
StatisticDefinition statDefinitionCount = new StatisticDefinition("POP", StatisticType.Count, "CityCount");
// Add the statistics definitions to a list
List <StatisticDefinition> statDefinitions = new List <StatisticDefinition>
{
statDefinitionAvgPop,
statDefinitionCount,
statDefinitionMinPop,
statDefinitionMaxPop,
statDefinitionSumPop,
statDefinitionStdDevPop,
statDefinitionVarPop
};
// Create the statistics query parameters, pass in the list of definitions
StatisticsQueryParameters statQueryParams = new StatisticsQueryParameters(statDefinitions);
// If only using features in the current extent, set up the spatial filter for the statistics query parameters
if (_onlyInExtentSwitch.Checked)
{
// Get the current extent (envelope) from the map view
Envelope currentExtent = _myMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry as Envelope;
// Set the statistics query parameters geometry with the envelope
statQueryParams.Geometry = currentExtent;
// Set the spatial relationship to Intersects (which is the default)
statQueryParams.SpatialRelationship = SpatialRelationship.Intersects;
}
// If only evaluating the largest cities (over 5 million in population), set up an attribute filter
if (_onlyBigCitiesSwitch.Checked)
{
// Set a where clause to get the largest cities (could also use "POP_CLASS = '5,000,000 and greater'")
statQueryParams.WhereClause = "POP_RANK = 1";
}
// Execute the statistical query with these parameters and await the results
StatisticsQueryResult statQueryResult = await _worldCitiesTable.QueryStatisticsAsync(statQueryParams);
// Display results in a list in a dialog
List <KeyValuePair <string, object> > statsList = statQueryResult.First().Statistics.ToList();
ShowStatsList(statsList);
}
// Execute a statistical query using the parameters defined by the user and display the results
private async void OnExecuteStatisticsQueryClicked(object sender, RoutedEventArgs e)
{
// Verify that there is at least one statistic definition
if (_statDefinitions.Count == 0)
{
MessageBox.Show("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(_statDefinitions);
// Specify the group fields (if any)
foreach (string groupField in _groupByFields)
{
statQueryParams.GroupByFieldNames.Add(groupField);
}
// Specify the fields to order by (if any)
foreach (OrderBy orderBy in _orderByFields)
{
statQueryParams.OrderByFields.Add(orderBy);
}
// 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);
// Format the output, and display results in the tree view
ILookup <string, IReadOnlyDictionary <string, object> > groupedResults = statQueryResult.ToLookup(r => string.Join(", ", r.Group.Values), r => r.Statistics);
ResultsTreeView.ItemsSource = groupedResults;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "Invalid statistics definitions");
}
}
private async void QueryStatistics(bool onlyInExtent, bool onlyLargePop)
{
// Create definitions for each statistic to calculate.
StatisticDefinition statDefinitionAvgPop = new StatisticDefinition("POP", StatisticType.Average, "");
StatisticDefinition statDefinitionMinPop = new StatisticDefinition("POP", StatisticType.Minimum, "");
StatisticDefinition statDefinitionMaxPop = new StatisticDefinition("POP", StatisticType.Maximum, "");
StatisticDefinition statDefinitionSumPop = new StatisticDefinition("POP", StatisticType.Sum, "");
StatisticDefinition statDefinitionStdDevPop = new StatisticDefinition("POP", StatisticType.StandardDeviation, "");
StatisticDefinition statDefinitionVarPop = new StatisticDefinition("POP", StatisticType.Variance, "");
// Create a definition for count that includes an alias for the output.
StatisticDefinition statDefinitionCount = new StatisticDefinition("POP", StatisticType.Count, "CityCount");
// Add the statistics definitions to a list.
List <StatisticDefinition> statDefinitions = new List <StatisticDefinition>
{
statDefinitionAvgPop,
statDefinitionCount,
statDefinitionMinPop,
statDefinitionMaxPop,
statDefinitionSumPop,
statDefinitionStdDevPop,
statDefinitionVarPop
};
// Create the statistics query parameters, pass in the list of definitions.
StatisticsQueryParameters statQueryParams = new StatisticsQueryParameters(statDefinitions);
// If only using features in the current extent, set up the spatial filter for the statistics query parameters.
if (onlyInExtent)
{
// Get the current extent (envelope) from the map view.
Envelope currentExtent = _myMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry as Envelope;
// Set the statistics query parameters geometry with the current extent.
statQueryParams.Geometry = currentExtent;
// Set the spatial relationship to Intersects (which is the default).
statQueryParams.SpatialRelationship = SpatialRelationship.Intersects;
}
// If only evaluating the largest cities (over 5 million in population), set up an attribute filter.
if (onlyLargePop)
{
// Set a where clause to get the largest cities (could also use "POP_CLASS = '5,000,000 and greater'").
statQueryParams.WhereClause = "POP_RANK = 1";
}
try
{
// Execute the statistical query with these parameters and await the results.
StatisticsQueryResult statQueryResult = await _worldCitiesTable.QueryStatisticsAsync(statQueryParams);
// Get the first (only) StatisticRecord in the results.
StatisticRecord record = statQueryResult.FirstOrDefault();
// Make sure a record was returned.
if (record == null || record.Statistics.Count == 0)
{
ShowMessage("No result", "No results were returned.");
return;
}
// Display results.
ShowStatsList(record.Statistics);
}
catch (ArcGISWebException exception)
{
ShowMessage("There was a problem running the query.", exception.ToString());
}
}
private async void OnExecuteStatisticsQueryClicked(object sender, EventArgs e)
{
// Create definitions for each statistic to calculate
StatisticDefinition statDefinitionAvgPop = new StatisticDefinition("POP", StatisticType.Average, "");
StatisticDefinition statDefinitionMinPop = new StatisticDefinition("POP", StatisticType.Minimum, "");
StatisticDefinition statDefinitionMaxPop = new StatisticDefinition("POP", StatisticType.Maximum, "");
StatisticDefinition statDefinitionSumPop = new StatisticDefinition("POP", StatisticType.Sum, "");
StatisticDefinition statDefinitionStdDevPop = new StatisticDefinition("POP", StatisticType.StandardDeviation, "");
StatisticDefinition statDefinitionVarPop = new StatisticDefinition("POP", StatisticType.Variance, "");
// Create a definition for count that includes an alias for the output
StatisticDefinition statDefinitionCount = new StatisticDefinition("POP", StatisticType.Count, "CityCount");
// Add the statistics definitions to a list
List <StatisticDefinition> statDefinitions = new List <StatisticDefinition>
{
statDefinitionAvgPop,
statDefinitionCount,
statDefinitionMinPop,
statDefinitionMaxPop,
statDefinitionSumPop,
statDefinitionStdDevPop,
statDefinitionVarPop
};
// Create the statistics query parameters, pass in the list of definitions
StatisticsQueryParameters statQueryParams = new StatisticsQueryParameters(statDefinitions);
// If only using features in the current extent, set up the spatial filter for the statistics query parameters
if (OnlyInExtentSwitch.IsToggled)
{
// Get the current extent (envelope) from the map view
Envelope currentExtent = MyMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry as Envelope;
// Set the statistics query parameters geometry with the envelope
statQueryParams.Geometry = currentExtent;
// Set the spatial relationship to Intersects (which is the default)
statQueryParams.SpatialRelationship = SpatialRelationship.Intersects;
}
// If only evaluating the largest cities (over 5 million in population), set up an attribute filter
if (OnlyBigCitiesSwitch.IsToggled)
{
// Set a where clause to get the largest cities (could also use "POP_CLASS = '5,000,000 and greater'")
statQueryParams.WhereClause = "POP_RANK = 1";
}
try
{
// Execute the statistical query with these parameters and await the results
StatisticsQueryResult statQueryResult = await _worldCitiesTable.QueryStatisticsAsync(statQueryParams);
// Display results in the list box
StatResultsList.ItemsSource = statQueryResult.First().Statistics.Select(m => $"{m.Key}:{m.Value}").ToList();
ResultsGrid.IsVisible = true;
}
catch (Exception ex)
{
await Application.Current.MainPage.DisplayAlert("Error", ex.Message, "OK");
}
}
private async void OnExecuteStatisticsQueryClicked(object sender, EventArgs e)
{
// Create definitions for each statistic to calculate
StatisticDefinition statDefinitionAvgPop = new StatisticDefinition("POP", StatisticType.Average, "");
StatisticDefinition statDefinitionMinPop = new StatisticDefinition("POP", StatisticType.Minimum, "");
StatisticDefinition statDefinitionMaxPop = new StatisticDefinition("POP", StatisticType.Maximum, "");
StatisticDefinition statDefinitionSumPop = new StatisticDefinition("POP", StatisticType.Sum, "");
StatisticDefinition statDefinitionStdDevPop = new StatisticDefinition("POP", StatisticType.StandardDeviation, "");
StatisticDefinition statDefinitionVarPop = new StatisticDefinition("POP", StatisticType.Variance, "");
// Create a definition for count that includes an alias for the output
StatisticDefinition statDefinitionCount = new StatisticDefinition("POP", StatisticType.Count, "CityCount");
// Add the statistics definitions to a list
List <StatisticDefinition> statDefinitions = new List <StatisticDefinition>
{
statDefinitionAvgPop,
statDefinitionCount,
statDefinitionMinPop,
statDefinitionMaxPop,
statDefinitionSumPop,
statDefinitionStdDevPop,
statDefinitionVarPop
};
// Create the statistics query parameters, pass in the list of definitions
StatisticsQueryParameters statQueryParams = new StatisticsQueryParameters(statDefinitions);
// If only using features in the current extent, set up the spatial filter for the statistics query parameters
if (_onlyInExtentSwitch.On)
{
// Get the current extent (envelope) from the map view
Envelope currentExtent = _myMapView.GetCurrentViewpoint(ViewpointType.BoundingGeometry).TargetGeometry as Envelope;
// Set the statistics query parameters geometry with the envelope
statQueryParams.Geometry = currentExtent;
// Set the spatial relationship to Intersects (which is the default)
statQueryParams.SpatialRelationship = SpatialRelationship.Intersects;
}
// If only evaluating the largest cities (over 5 million in population), set up an attribute filter
if (_onlyBigCitiesSwitch.On)
{
// Set a where clause to get the largest cities (could also use "POP_CLASS = '5,000,000 and greater'")
statQueryParams.WhereClause = "POP_RANK = 1";
}
// Execute the statistical query with these parameters and await the results
StatisticsQueryResult statQueryResult = await _worldCitiesTable.QueryStatisticsAsync(statQueryParams);
// Get the first (only) StatisticRecord in the results
StatisticRecord record = statQueryResult.FirstOrDefault();
// Make sure a record was returned
if (record == null || record.Statistics.Count == 0)
{
// Notify the user that no results were returned
UIAlertView alert = new UIAlertView();
alert.Message = "No results were returned";
alert.Title = "Statistical Query";
alert.Show();
return;
}
// Display results
IReadOnlyDictionary <string, object> statistics = record.Statistics;
ShowStatsList(statistics);
}
