Common_Callback_CSharp\Default.aspx.cs
// Copyright 2010 ESRI // // All rights reserved under the copyright laws of the United States // and applicable international laws, treaties, and conventions. // // You may freely redistribute and use this sample code, with or // without modification, provided you include the original copyright // notice and use restrictions. // // See the use restrictions. // public partial class Default : System.Web.UI.Page, System.Web.UI.ICallbackEventHandler { #region Instance Variable Declarations private string m_ADFCallbackFunctionString; private string m_CallbackResults; #endregion #region ASP.NET Page Event Handlers protected void Page_Load(object sender, System.EventArgs e) { // Define the parameters for a browser call to the WebForm_DoCallback JavaScript function // via the GetCallbackEventReference function. The GetCallbackEventReference function returns // the syntax for initiating a callback (i.e a call to WebForm_DoCallback) with the passed-in // parameters. Here the parameters are defined as follows: // this - the Page will handle the callback request // "message" - a JavaScript variable named "message" will contain argument value pairs in // the callback // "processCallbackResult" - name of the JavaScript function to process the callback // response from the Page. This function is included with // the Web ADF JavaScript Library. // "context" - a JavaScript variable named "context" which can be used by the browser to // indicate the origin of the callback // "postBackError" - name of the JavaScript function to process errors returned during // callback processing. // true - define whether the callback is synchronous or asynchronous. True is asynchronous. m_ADFCallbackFunctionString = Page.ClientScript.GetCallbackEventReference(this, "message", "processCallbackResult", "context", "postBackError", true); } #endregion #region Web ADF Control Event Handlers // Event that fires when the map extent changes. Wired to the map in the map control's HTML declaration protected void Map1_ExtentChanged(object sender, ESRI.ArcGIS.ADF.Web.UI.WebControls.ExtentEventArgs extentEventArgs) { try { // Get the new extent of the map (extent after the extent changed) and store in a Web ADF envelope ESRI.ArcGIS.ADF.Web.Geometry.Envelope adfEnvelope = extentEventArgs.NewExtent; // Create a SortedList object containing four key-value pairs, each containing one bound of the // new extent and the id of the HTML div that will be updated to display that bound. "N" is // passed to double.ToString to specify a numeric format in converting the coordinate. System.Collections.Generic.SortedList<string, string> extentList = new System.Collections.Generic.SortedList<string, string>(); extentList.Add("LabelN", adfEnvelope.YMax.ToString("N")); extentList.Add("LabelE", adfEnvelope.XMax.ToString("N")); extentList.Add("LabelS", adfEnvelope.YMin.ToString("N")); extentList.Add("LabelW", adfEnvelope.XMin.ToString("N")); // Iterate through each pair in the list and create a callback result to update the extent divs foreach (System.Collections.Generic.KeyValuePair<string, string> keyValuePair in extentList) { // Get the extent bound coordinate of the current list item string extentBound = keyValuePair.Value.ToString(); // Get the div ID that should be updated with extentBound from the current list item string extentDivId = keyValuePair.Key.ToString(); // Create a callback result that will update the div specified by extentDivId with the // value specified by extentBound. To do this, we pass the CallbackResult constructor the // following parameters: // "div" - the type of control/element we want updated // extentDivId - the client-side ID of the control/element we want updated // "innercontent" - the type of action we want to be performed. "innercontent" specifies that // we want to replace the inner HTML (what's inside the element tags) of the specified // control/element // extentBound - the value to use in the specified action. In this case, it is the value // to replace the div's inner HTML with. ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult callbackResult = ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult.CreateSetInnerContent(extentDivId, extentBound); // Add the callback result to the map. Since the map control initiated the callback when // its extent changed, it is the map control's callback results that will be processed when // the callback returns to the client. Map1.CallbackResults.Add(callbackResult); } } catch (System.Exception exception) { ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult errorCallbackResult = ErrorHandling.GetErrorCallback(exception); Map1.CallbackResults.Add(errorCallbackResult); } } #endregion #region ICallbackEventHandler Members // The Zoom To Point button is wired to invoke the JavaScript function ZoomToPointClient // (defined in Default.aspx), which in turn invokes the JavaScript callback function. So when // the button is clicked, a callback is initiated, causing RaiseCallbackEvent and // GetCallbackResult to be called. // // The items on the Zoom To Location menu are wired similarly, as on click they call the JavaScript // function ZoomToLocationClient (also defined in Default.aspx), which also in turn calls the // JavaScript callback. // // We therefore add code to RaiseCallbackEvent and GetCallbackResult to parse the arguments // passed in the callbacks, take action accordingly, and return a callback response to the client. public void RaiseCallbackEvent(string eventArgs) { try { // Parse the callback string passed from the client to the server into separate // arguments using the Web ADF's callback parsing utility. System.Collections.Specialized.NameValueCollection nameValueCollection = ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackUtility.ParseStringIntoNameValueCollection(eventArgs); // Check the value of the main event argument (EventArg) and take action accordingly if (nameValueCollection["EventArg"] == "ZoomToPoint") { // Call the method that will center the map at the passed-in coordinates and zoom by a factor // of four. ZoomToPointServer(nameValueCollection["X"], nameValueCollection["Y"]); } else if (nameValueCollection["EventArg"] == "ZoomToLocation") { // Call the method that will zoom the map to the passed-in location ZoomToLocationServer(nameValueCollection["Location"]); } } catch (System.Exception exception) { ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult errorCallbackResult = ErrorHandling.GetErrorCallback(exception); Map1.CallbackResults.Add(errorCallbackResult); m_CallbackResults = Map1.CallbackResults.ToString(); } } // The last server-side method called before the callback returns to the browser, GetCallbackResult // is where the server-side result of the callback is passed back to the browser as a string for // processing by the client. public string GetCallbackResult() { // Return the instance variable containing the callback results return m_CallbackResults; } #endregion #region Instance Properties // Property allowing client-side access to the client callback function string. This string // contains the necessary JavaScript syntax to initiate a callback with the parameters specified // in GetCallbackEventReference (in Page_Load). public string ADFCallbackFunctionString { get { return m_ADFCallbackFunctionString; } set { m_ADFCallbackFunctionString = value; } } #endregion #region Instance Methods // Method that centers the map at the passed-in coordinates and zooms by a factor of 4 public void ZoomToPointServer(string xString, string yString) { try { // Convert the passed-in coordinates from strings to doubles double xCenter = double.Parse(xString); double yCenter = double.Parse(yString); // Create a Web ADF point from the passed-in coordinates ESRI.ArcGIS.ADF.Web.Geometry.Point adfCenterPoint = new ESRI.ArcGIS.ADF.Web.Geometry.Point(xCenter, yCenter); // Center the map at the point Map1.CenterAt(adfCenterPoint); // Zoom the map by a factor of 4 Map1.Zoom(4); } catch (System.Exception exception) { ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult errorCallbackResult = ErrorHandling.GetErrorCallback(exception); Map1.CallbackResults.Add(errorCallbackResult); } // Update the instance variable storing callback results with the callback results of the // map control. Since we've manipulated the map, its callback results must be returned // to the client for our changes to show up. And since it was not the map control that // intitiated the callback, but rather a custom JavaScript function, the map control is // not checked for callback results when the callback returns to the client. m_CallbackResults = Map1.CallbackResults.ToString(); } // Method that zooms the map to the passed-in location public void ZoomToLocationServer(string location) { try { // Declare and initialze a variable to store whether the passed-in location is // one listed on the Zoom To Location menu bool validLocation = false; // Get the root menu item of the Zoom To Menu System.Web.UI.WebControls.MenuItem rootMenuItem = Menu1.Items[0]; // Iterate through the items directly below the root item foreach (System.Web.UI.WebControls.MenuItem menuItem in rootMenuItem.ChildItems) { // Check whether the current menu item's text matches the passed-in location if (menuItem.Text == location) { // the text matches the location, meaning the location is valid validLocation = true; break; } } if (validLocation) { // Declare and initialize variables to store the bounds of the new map extent double minX = 0; double minY = 0; double maxX = 0; double maxY = 0; // Check the passed-in location and initialize the extent parameters accordingly switch (location) { case "California": minX = -128.0; minY = 31.0; maxX = -111.0; maxY = 43.0; break; case "New York": minX = -80.0; minY = 40.5; maxX = -73.0; maxY = 45.5; break; case "Kansas": minX = -103.0; minY = 35.0; maxX = -93.0; maxY = 42.0; break; default: break; } // Create a Web ADF envelope with the new extent parameters ESRI.ArcGIS.ADF.Web.Geometry.Envelope adfNewExtentEnvelope = new ESRI.ArcGIS.ADF.Web.Geometry.Envelope(minX, minY, maxX, maxY); // Update the map control's extent with the newly created envelope Map1.Extent = adfNewExtentEnvelope; // Update the instance variable storing callback results with the callback results of the // map control. Since we've manipulated the map, its callback results must be returned // to the client for our changes to show up. And since it was not the map control that // intitiated the callback, but rather a custom JavaScript function, the map control is // not checked for callback results when the callback returns to the client. m_CallbackResults = Map1.CallbackResults.ToString(); } else { // The location was not valid, so we don't need to pass any callback results to the client m_CallbackResults = ""; } } catch (System.Exception exception) { ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult errorCallbackResult = ErrorHandling.GetErrorCallback(exception); Map1.CallbackResults.Add(errorCallbackResult); m_CallbackResults = Map1.CallbackResults.ToString(); } } #endregion }