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asp.net : Bind controls to object
Hello,
I have an aspx page with some controls like textboxes on it and a button to save the entered values. In the code-behind I declared a public variabele of an object, for example: public Person _prs = new Person(); Where Person is a class with some properties, like FirstName and LastName. The textboxes display the values in this way: Text = '<%# _prs.FirstName #>' and for another Textbox: Text = '<%# _prs.LastName #>' When the user clicks on the save button, the page_load event happens first, so my public Person is always set to a new Person() again and therefore I can't use the variable _prs to see the new entered values in the textboxes. My question is: how can I bind my textboxes to the properties of the public variable _prs, so the values that are entered in the textboxes immediately are updated in the Person object and how can I preserve these values, so I can use the Person object in the button-save click event? Greetings, Chris
[quoted text, click to view]
On Feb 13, 1:52 pm, Chris Zopers <test123tes...@12move.nl> wrote: > Hello, > > I have an aspx page with some controls like textboxes on it and a button > to save the entered values. > > In the code-behind I declared a public variabele of an object, for > example: > > public Person _prs = new Person(); > > Where Person is a class with some properties, like FirstName and > LastName. The textboxes display the values in this way: Text = '<%# > _prs.FirstName #>' and for another Textbox: Text = '<%# _prs.LastName > #>' > > When the user clicks on the save button, the page_load event happens > first, so my public Person is always set to a new Person() again and > therefore I can't use the variable _prs to see the new entered values in > the textboxes. > > My question is: how can I bind my textboxes to the properties of the > public variable _prs, so the values that are entered in the textboxes > immediately are updated in the Person object and how can I preserve > these values, so I can use the Person object in the button-save click > event? > > Greetings, > Chris > > *** Sent via Developersdexhttp://www.developersdex.com*** Do expose a property of your desired type encapsulating it in a viewstate or session. for example public person myperson { get { if(viewstate["myperson"]==null; viewstate["myperson"] = new Person(); return (person)viewstate["myperson"] } set { viewstate["myperson"] = value; } } Bind you stuff with the property ... after postback... again update the property values... Hope this help Masudur http://www.shatkotha.com
the ObjectDataSource class is used for this. There are several examples in
the docs that should help you. -- bruce (sqlwork.com) [quoted text, click to view] "Chris Zopers" wrote:
> Hello, > > I have an aspx page with some controls like textboxes on it and a button > to save the entered values. > > In the code-behind I declared a public variabele of an object, for > example: > > public Person _prs = new Person(); > > Where Person is a class with some properties, like FirstName and > LastName. The textboxes display the values in this way: Text = '<%# > _prs.FirstName #>' and for another Textbox: Text = '<%# _prs.LastName > #>' > > When the user clicks on the save button, the page_load event happens > first, so my public Person is always set to a new Person() again and > therefore I can't use the variable _prs to see the new entered values in > the textboxes. > > My question is: how can I bind my textboxes to the properties of the > public variable _prs, so the values that are entered in the textboxes > immediately are updated in the Person object and how can I preserve > these values, so I can use the Person object in the button-save click > event? > > Greetings, > Chris > > > > > > > > *** Sent via Developersdex http://www.developersdex.com ***
[quoted text, click to view] "Masudur" <munnacs@gmail.com> wrote in message news:c8ab04a7-d635-483a-82fa-48a54abb58d5@j20g2000hsi.googlegroups.com... > On Feb 13, 1:52 pm, Chris Zopers <test123tes...@12move.nl> wrote: >> Hello, >> >> I have an aspx page with some controls like textboxes on it and a button >> to save the entered values. >> >> In the code-behind I declared a public variabele of an object, for >> example: >> >> public Person _prs = new Person(); >> >> Where Person is a class with some properties, like FirstName and >> LastName. The textboxes display the values in this way: Text = '<%# >> _prs.FirstName #>' and for another Textbox: Text = '<%# _prs.LastName >> #>' >> >> When the user clicks on the save button, the page_load event happens >> first, so my public Person is always set to a new Person() again and >> therefore I can't use the variable _prs to see the new entered values in >> the textboxes. >> >> My question is: how can I bind my textboxes to the properties of the >> public variable _prs, so the values that are entered in the textboxes >> immediately are updated in the Person object and how can I preserve >> these values, so I can use the Person object in the button-save click >> event? >> >> Greetings, >> Chris >> >> *** Sent via Developersdexhttp://www.developersdex.com*** > > Do expose a property of your desired type encapsulating it in a > viewstate or session. > for example > public person myperson > { > get > { > if(viewstate["myperson"]==null; > viewstate["myperson"] = new Person(); > return (person)viewstate["myperson"] > } > set > { > viewstate["myperson"] = value; > } > } > > Bind you stuff with the property ... > after postback... > again update the property values... I believe that in order to use the viewstate as you suggest he would need to ensure that the Person class is serializable (and may need to implement an interface). The OP also needs to realize that by default the Person class will be sent to the browser and back, which incurs overhead and is a potential security risk.
[quoted text, click to view] "Chris Zopers" <test123test12@12move.nl> wrote in message news:eAgjVVhbIHA.4752@TK2MSFTNGP02.phx.gbl... > Hello, > > I have an aspx page with some controls like textboxes on it and a button > to save the entered values. > > In the code-behind I declared a public variabele of an object, for > example: > > public Person _prs = new Person(); > > Where Person is a class with some properties, like FirstName and > LastName. The textboxes display the values in this way: Text = '<%# > _prs.FirstName #>' and for another Textbox: Text = '<%# _prs.LastName > #>' > > When the user clicks on the save button, the page_load event happens > first, so my public Person is always set to a new Person() again and > therefore I can't use the variable _prs to see the new entered values in > the textboxes. > > My question is: how can I bind my textboxes to the properties of the > public variable _prs, so the values that are entered in the textboxes > immediately are updated in the Person object and how can I preserve > these values, so I can use the Person object in the button-save click > event? Session is a good candidate: if (!IsPostBack) { Person _prs = Session["prs"] as Person; if (_prs == null) _prs = new Person(); // or throw an exception } else _prs = new Person(); Session["prs"] = _prs; However, we actually reload the object from the database based on a query string parameter: Guid id = new Guid(QueryString["id"]); Person _prs = new Person(id); // Loads person from DB if "id" exists. Otherwise gives a new object.
Hello Bruce,
I indeed already tried the ObjecDataSource, but I ran into an other problem with that. I've posted a question about my new problem in this newsgroup, here's the text of this new problem: Hello, I have some textboxes in a FormView control. The FormView is bound to an ObjectDataSource. The ObjectDataSource has a SelectMethod that gets an object and the textboxes in the FormView are bound to the Object's properties. This all works fine. The ObjectDataSource also has an UpdateMethod that points to a function that accepts the whole object as a parameter. But when I call the ObjectDataSource.Update() method, the specified function is called, but the object-parameter is always a completely empty object. Does anyone recognize this problem and how can I solve this? Greetings, Chris
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