Help! Object reference...

waterfall

21y2.4k.NET

Hi! Can someone help me please, I get this error when I run application: Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.NullReferenceException: Object reference not set to an instance of an object. Source Error: Line 52: public bool haveInited Line 53: { Line 54: get { return (bool)Session.Contents["haveInited"]; } Line 55: set { Session.Contents[ "haveInited" ] = value; } Line 56: } Source File: c:\inetpub\wwwroot\oxcet3\oxform.aspx.cs Line: 54 Stack Trace: [NullReferenceException: Object reference not set to an instance of an object.] ox4.Ox4Form.get_haveInited() in c:\inetpub\wwwroot\oxcet3\oxform.aspx.cs:54 ox4.Ox4Form.Page_Load(Object sender, EventArgs e) in c:\inetpub\wwwroot\oxcet3\oxform.aspx.cs:66 System.Web.UI.Control.OnLoad(EventArgs e) System.Web.UI.Control.LoadRecursive() System.Web.UI.Page.ProcessRequestMain() Application is C# generated from Prolog, using P# (Jon Cook is author of P#). Here is the link http://www.dcs.ed.ac.uk/home/jjc/psharp/psharp-1.1/dlpsharp.html It is P# example of game Noughts and Crosses. Problematic code is: public bool haveInited { get { return (bool)Session.Contents["haveInited"]; } set { Session.Contents[ "haveInited" ] = value; } } protected System.Web.UI.WebControls.Button[] Cells; private void Page_Load(object sender, System.EventArgs e) { Cells = new Button[] { Cell1, Cell2, Cell3, Cell4, Cell5, Cell6, Cell7, Cell8, Cell9, Cell10, Cell11, Cell12, Cell13, Cell14, Cell15, Cell16 }; if( !haveInited ) { haveInited = true; ResetBoard(); } } It fails on if(!haveInited) line...

6 Replies

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mibuyt21y ago
Hi, I am quite mix up. Do you mean the CSharp codes are generated through P#? If yes, when you try to run it, it cannot work? Hmm.. haha shouldn't you ask the author of P# since he developed that tool :p Sincerely, I have no idea how to solve your problem till i have the source code... at least i can justify better... Cheers.
waterfall21y ago
"Object reference error..." is now solved but main page doesn't cooperate with other *.cs files included in solution. These files are generated by P# from the Prolog file, and when user clicks on "ComputerMove" button "ResetBoard()" should initiate inter-operation with other files but it doesn't work. I put buttons on the form as they are shown in screenshot and named them as in code (Cell1...)... There is no any error but logic of these other files doesn't work. Simply ComputerMove button always resets board and draws "X" in first top-left cell. I'm student and I'm having a talk about P# (logic and object oriented programming - link in first post) so I need to show that example. Anyway if You don't have time to test all these, doesn't matter. I am very grateful for help with that first error. Sorry if my English isn't 100% correct... Thanks again.
mibuyt21y ago
Sure :) Hope you get it working. Just post it here if you have future doubts :)
waterfall21y ago
Thanks!
mibuyt21y ago
Ooops... well "test" is just for my personal testing... it should be this instead: Before get { return (bool)Session.Contents["haveInited"]; } After: get { return Convert.ToBoolean(Session.Contents["haveInited"]); } Sorry :( Cheers.
mibuyt21y ago
Hi, Replace to this: Before get { return (bool)Session.Contents["haveInited"]; } After: get { return Convert.ToBoolean(Session.Contents["test"]); } Hope it helps. I have tested it here and it worked fine :) Cheers.