// Initializes the popup title on a graphics layer, given the title field name
private void setPopupTitle(string titleField, GraphicsLayer layer)
{
Dictionary <int, string> expression = new Dictionary <int, string>();
expression.Add(-1, string.Format("{{{0}}}", titleField));
LayerProperties.SetPopupTitleExpressions(Target, expression);
}
protected override void Invoke(object parameter)
{
// Make sure the target is a GraphicsLayer
if (Target != null && Target is GraphicsLayer)
{
// Check whether a title expression has been defined
if (string.IsNullOrEmpty(TitleExpression))
{
// No title expression, so auto-initialize popups
// If the target layer is a feature layer, check whether the service metadata specifies a display field
if (Target is FeatureLayer)
{
FeatureLayer fLayer = (FeatureLayer)Target;
// Check if the layer's metadata defines a display field
if (fLayer.LayerInfo != null && !string.IsNullOrEmpty(fLayer.LayerInfo.DisplayField))
{
// use the display field
setPopupTitle(fLayer.LayerInfo.DisplayField, fLayer);
return;
}
else if (!fLayer.IsInitialized)
{
// Wait for the layer to initialize and check again
fLayer.Initialized += Layer_Initialized;
return;
}
}
// The layer is not a feature layer (i.e. does not have metadata), so auto-determine the display field
// based on the graphics in the layer
initPopupTitleFromGraphics((GraphicsLayer)Target);
}
else
{
// A title expression has been explicitly defined, so use that
Dictionary <int, string> expression = new Dictionary <int, string>();
expression.Add(-1, TitleExpression);
LayerProperties.SetPopupTitleExpressions(Target, expression);
}
}
}
/// <summary>
/// Sets the title of the pop-up
/// </summary>
/// <remarks>
/// In cases where the pop-up title is not set automatically (and therefore results in a blank title),
/// this method loops through the fields in the layer to determine an appropriate title to display.
/// </remarks>
private void SetPopupTitleExpression()
{
// Dictionary with integer keys and string values. Integer keys are layer ids: -1 for a GraphicLayer,
// otherwise Layer ID. String values are format strings like this: "{NAME}: {POPULATION}"
IDictionary <int, string> titleExpression = new Dictionary <int, string>();
// Check that the LayerInfo and DisplayField are not null. Use the DisplayField if it exists.
if (resultsLayer.LayerInfo != null && resultsLayer.LayerInfo.DisplayField != null)
{
string layerInfoDisplayField = resultsLayer.LayerInfo.DisplayField;
string displayFieldExpression = "{" + layerInfoDisplayField + "}";
titleExpression.Add(-1, displayFieldExpression);
LayerProperties.SetPopupTitleExpressions(resultsLayer, titleExpression);
}
else // display field is null
{
// Create a list of all the fields in the layer
List <Field> fields = resultsLayer.LayerInfo.Fields;
// Loop through each field to see if there is a FieldName called "Name"(case-insensitive).
foreach (Field field in fields)
{
string fieldName = field.FieldName;
if (fieldName != null)
{
if (string.Compare(fieldName, "Name", StringComparison.InvariantCultureIgnoreCase) == 0)
{
titleExpression.Add(-1, "{" + fieldName + "}");
LayerProperties.SetPopupTitleExpressions(resultsLayer, titleExpression);
return; // If the Popup title expression is set, exit.
}
}
}
// Loop through each field to see if there is a FieldName that contains "Name" (case-insensitive).
foreach (Field field in fields)
{
string fieldName = field.FieldName;
if (fieldName != null)
{
// if index is -1 then the FieldName does not contain "Name" (case-insensitive)
int index = fieldName.IndexOf("Name", StringComparison.InvariantCultureIgnoreCase);
if (index >= 0)
{
titleExpression.Add(-1, "{" + fieldName + "}");
LayerProperties.SetPopupTitleExpressions(resultsLayer, titleExpression);
return; // If the Popup title expression is set, exit.
}
}
}
// Loop through each field and look for the first field that is both visible in the pop-up attribute list and is a string
foreach (Field field in fields)
{
string fieldName = field.FieldName;
foreach (FieldSettings fSetting in popupInfo.PopupItem.FieldInfos)
{
if (fieldName != null && fieldName == fSetting.Name && fSetting.FieldType == FieldType.Text)
{
titleExpression.Add(-1, "{" + fieldName + "}");
LayerProperties.SetPopupTitleExpressions(resultsLayer, titleExpression);
}
return;
}
}
}
}
