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unable to access User Control data HELP
Web Programming266
All, myself and another developer have been staring blankly at a screen for the past 48 hours and are wondering just what stunningly obvious thing we are missing. We are trying to load up 2 or more user controls dynamically by adding to a placeholder defined in page_load. I've included the sample code for how we are accessing one. The user controls are not rocket science - just a few text boxes with public accessor properties. We've trawled through all the newsgroups and have: (1) declared class scope variables that are visible throughout the class (2) declared the User Controls outside of an isPostBack check so they are always created (3) defined public get and set methods in each user control to the container page can access the data. (4) we have made sure that we are casting object to the correct type coming in and out of the Placeholder collection when we build and step through we find that when we enter the onClick() function if we try to access the placeholder collection, we get an IndexOutOfBounds exception - the collection has NO ELEMENTS ANY MORE!!! If we try to access the User Control by means of it's class scope variable we get a NullReference Exception. what are we missing - this is driving us nuts...... sample code to follow, many thanks Paul. namespace local.NewReg { //all our usings using System; using System.Collections; using System.ComponentModel; using System.Data; using System.Drawing; using System.Web; using System.Web.SessionState; using System.Web.UI; /// <summary> /// Summary description for registration. /// </summary> public class registration : System.Web.UI.Page { //class scope placeholder protected System.Web.UI.WebControls.PlaceHolder personal; //class scope variable for our User Control protected local.NewReg.webuser userTest; //class scope declaration of a Csharp server object protectedQA.Person.WebUserPerson person = null; private void Page_Load(object sender, System.EventArgs e) { // Put user code to initialize the page here //outside of a postback command so that the controls are always loaded //Load user controls //load the User control and cast it to the variable type userTest = (local.NewReg.webuser)Page.LoadControl("MyUserControl.ascx"); //add to the placeholder - will be stored as an object of type Control personal.Controls.Add(userTest); //we also tried this... //c is local but we will access via a class scope variable.. //Control c = Page.LoadControl("MyUserControl.ascx"); //personal.Controls.Add(c); //and we also tried this.. //userTest= Page.LoadControl("/NewReg/MyUserControl.ascx"); //Personal.Controls.Add(userTest); } public void submitClick(object Source, ImageClickEventArgs e) { try { //get access to out webuser person = new QA.Person.WebUserPerson(); //..now try to get access to the user control from the submitClick() function //doing this throws an indexOurOfRangeException //which is weird because it should have one control in the collection as defined in page_load userTest = (local.NewReg.webuser)Personal.Controls[0]; person.firstName = userTest.FirstName; //or accessing the variable directly throws a NullreferenceException //which I don't get because we have instantiated the variable in page_load person.firstName = userTest.FirstName; } catch(Exception exc) {// handle errors gracefully} } #region Web Form Designer generated code override protected void OnInit(EventArgs e) { // // CODEGEN: This call is required by the ASP.NET Web Form Designer. // InitializeComponent(); base.OnInit(e); } /// <summary> /// Required method for Designer support - do not modify /// the contents of this method with the code editor. /// </summary> private void InitializeComponent() { this.Load += new System.EventHandler(this.Page_Load); } #endregion } } - |