"Steven" <steven***@gmail.com> ha scritto nel messaggio
news:1152690634.983346.142530@i42g2000cwa.googlegroups.com...
> Hello All,
>
> I have a fairly simple question regarding best practises for Composite
> controls.
>
> If I want to save into ViewState the data from a postback to a
> ChildControl, I set a property of the Composite Control. This can't be
> done from the CreateChildControl class because the child controls are
> not yet populated with the postback data at this point. I have
> therefore being setting the property that will store this data into
> view state in the event handler for the child control. I have provided
> an example below where the postback data of a text control is saved to
> a property of the Composite Control when the Event Handler of the
> TextBox is called. Is this a suitable way to peform this or is there a
> better practise to use?
>
>    public class CustomTextBox : CompositeControl
>    {
>        public event EventHandler TextChanged;
>
>        protected Label label;
>        protected TextBox textBox;
>
>        public string Title
>        {
>            get { return (string)ViewState["Title"]; }
>            set { ViewState["Title"] = value; }
>        }
>
>        public string Text
>        {
>            get { return (string)ViewState["Text"]; }
>            set { ViewState["Text"] = value; }
>        }
>
>        protected override void CreateChildControls()
>        {
>            // Add the label
>            label = new Label();
>            label.EnableViewState = false;
>            label.Text = Title;
>            Controls.Add(label);
>
>            // Add the textbox
>            textBox = new TextBox();
>            textBox.EnableViewState = false;
>            textBox.Text = Text;
>            textBox.TextChanged += new EventHandler(OnTextChanged);
>            Controls.Add(textBox);
>        }
>
>        protected virtual void OnTextChanged(object sender, EventArgs
> e)
>        {
>            if (TextChanged != null)
>            {
>                // Set the property of the Composite Control to store
> the Text in ViewState
>                Text = textBox.Text;
>                TextChanged(this, e);
>            }
>        }
>    }
>

"Alessandro Zifiglio" <AlessandroZifiglio @ -h-o-t-m-a-i-l-c-o-m> ha scritto
nel messaggio news:eHClqTZpGHA.756@TK2MSFTNGP05.phx.gbl...
> hi Steven, viewstate is already maintained by the individual controls that
> you are using (label, textbox). So in your text and title properties, get
> accessor, check if the text of both your label and textbox are not empty
> and if they are not then pull the values from here. Since you are
> inheriting CompositeControls, you shouldnt have a problem because it
> already ensures that CreateChildControls is already called prior to
> pulling the values from the controls.
> Also as you can see, your disabling viewstate on the textbox will produce
> an unwanted result since the textchanged event of the textbox will fire,
> regardless the text has changed or not. This is because since you disabled
> viewstate it does not compare old and new values, not being able to do so,
> it simply fires this event regardless.
>
> Regards,
> Alessandro Zifiglio
> http://www.AsyncUI.net
> "Steven" <steven***@gmail.com> ha scritto nel messaggio
> news:1152690634.983346.142530@i42g2000cwa.googlegroups.com...
>> Hello All,
>>
>> I have a fairly simple question regarding best practises for Composite
>> controls.
>>
>> If I want to save into ViewState the data from a postback to a
>> ChildControl, I set a property of the Composite Control. This can't be
>> done from the CreateChildControl class because the child controls are
>> not yet populated with the postback data at this point. I have
>> therefore being setting the property that will store this data into
>> view state in the event handler for the child control. I have provided
>> an example below where the postback data of a text control is saved to
>> a property of the Composite Control when the Event Handler of the
>> TextBox is called. Is this a suitable way to peform this or is there a
>> better practise to use?
>>
>>    public class CustomTextBox : CompositeControl
>>    {
>>        public event EventHandler TextChanged;
>>
>>        protected Label label;
>>        protected TextBox textBox;
>>
>>        public string Title
>>        {
>>            get { return (string)ViewState["Title"]; }
>>            set { ViewState["Title"] = value; }
>>        }
>>
>>        public string Text
>>        {
>>            get { return (string)ViewState["Text"]; }
>>            set { ViewState["Text"] = value; }
>>        }
>>
>>        protected override void CreateChildControls()
>>        {
>>            // Add the label
>>            label = new Label();
>>            label.EnableViewState = false;
>>            label.Text = Title;
>>            Controls.Add(label);
>>
>>            // Add the textbox
>>            textBox = new TextBox();
>>            textBox.EnableViewState = false;
>>            textBox.Text = Text;
>>            textBox.TextChanged += new EventHandler(OnTextChanged);
>>            Controls.Add(textBox);
>>        }
>>
>>        protected virtual void OnTextChanged(object sender, EventArgs
>> e)
>>        {
>>            if (TextChanged != null)
>>            {
>>                // Set the property of the Composite Control to store
>> the Text in ViewState
>>                Text = textBox.Text;
>>                TextChanged(this, e);
>>            }
>>        }
>>    }
>>
>
>

> Also, try the following link, the code example might help you, though since
> you inherit CompositeControl you might not need to call EnsureChildControls,
> supposedly that is already taken care of for you when you inherit
> CompsiteControl class  :
> http://msdn2.microsoft.com/en-us/library/system.web.ui.control.ensurechildcontrols.aspx
> Regards,
> Alessandro Zifiglio
> http://www.AsyncUI.net
>
> "Alessandro Zifiglio" <AlessandroZifiglio @ -h-o-t-m-a-i-l-c-o-m> ha scritto
> nel messaggio news:eHClqTZpGHA.756@TK2MSFTNGP05.phx.gbl...
> > hi Steven, viewstate is already maintained by the individual controls that
> > you are using (label, textbox). So in your text and title properties, get
> > accessor, check if the text of both your label and textbox are not empty
> > and if they are not then pull the values from here. Since you are
> > inheriting CompositeControls, you shouldnt have a problem because it
> > already ensures that CreateChildControls is already called prior to
> > pulling the values from the controls.
> > Also as you can see, your disabling viewstate on the textbox will produce
> > an unwanted result since the textchanged event of the textbox will fire,
> > regardless the text has changed or not. This is because since you disabled
> > viewstate it does not compare old and new values, not being able to do so,
> > it simply fires this event regardless.
> >
> > Regards,
> > Alessandro Zifiglio
> > http://www.AsyncUI.net
> > "Steven" <steven***@gmail.com> ha scritto nel messaggio
> > news:1152690634.983346.142530@i42g2000cwa.googlegroups.com...
> >> Hello All,
> >>
> >> I have a fairly simple question regarding best practises for Composite
> >> controls.
> >>
> >> If I want to save into ViewState the data from a postback to a
> >> ChildControl, I set a property of the Composite Control. This can't be
> >> done from the CreateChildControl class because the child controls are
> >> not yet populated with the postback data at this point. I have
> >> therefore being setting the property that will store this data into
> >> view state in the event handler for the child control. I have provided
> >> an example below where the postback data of a text control is saved to
> >> a property of the Composite Control when the Event Handler of the
> >> TextBox is called. Is this a suitable way to peform this or is there a
> >> better practise to use?
> >>
> >>    public class CustomTextBox : CompositeControl
> >>    {
> >>        public event EventHandler TextChanged;
> >>
> >>        protected Label label;
> >>        protected TextBox textBox;
> >>
> >>        public string Title
> >>        {
> >>            get { return (string)ViewState["Title"]; }
> >>            set { ViewState["Title"] = value; }
> >>        }
> >>
> >>        public string Text
> >>        {
> >>            get { return (string)ViewState["Text"]; }
> >>            set { ViewState["Text"] = value; }
> >>        }
> >>
> >>        protected override void CreateChildControls()
> >>        {
> >>            // Add the label
> >>            label = new Label();
> >>            label.EnableViewState = false;
> >>            label.Text = Title;
> >>            Controls.Add(label);
> >>
> >>            // Add the textbox
> >>            textBox = new TextBox();
> >>            textBox.EnableViewState = false;
> >>            textBox.Text = Text;
> >>            textBox.TextChanged += new EventHandler(OnTextChanged);
> >>            Controls.Add(textBox);
> >>        }
> >>
> >>        protected virtual void OnTextChanged(object sender, EventArgs
> >> e)
> >>        {
> >>            if (TextChanged != null)
> >>            {
> >>                // Set the property of the Composite Control to store
> >> the Text in ViewState
> >>                Text = textBox.Text;
> >>                TextChanged(this, e);
> >>            }
> >>        }
> >>    }
> >>
> >
> >

"Steven" <steven***@gmail.com> ha scritto nel messaggio
news:1152750256.243939.142670@75g2000cwc.googlegroups.com...
> Thanks for the reply Alessandro,
>
> My thinking behind disabling View State for the child controls is for
> cases were the composite control contains more complex child controls
> which I thought would bloat the size of the web pages with view state
> data. Then only the important data needs to be persisted in the pages
> ViewState through the set and get calls of the Composite Controls
> properties.
>
> This introduces the problem you noted of the TextChanged event firing
> everytime the page posts back. This is why I added the code to store
> the text into the Composite Controls properties when the OnTextChanged
> event fires. This may not be a desirable location to set this data
> though, which may mean I will just have to enable View State for the
> child controls and deal with the extra web page size introduced.
>
> Cheers for the input.
>
>
> Alessandro Zifiglio wrote:
>> Also, try the following link, the code example might help you, though
>> since
>> you inherit CompositeControl you might not need to call
>> EnsureChildControls,
>> supposedly that is already taken care of for you when you inherit
>> CompsiteControl class  :
>> http://msdn2.microsoft.com/en-us/library/system.web.ui.control.ensurechildcontrols.aspx
>> Regards,
>> Alessandro Zifiglio
>> http://www.AsyncUI.net
>>
>> "Alessandro Zifiglio" <AlessandroZifiglio @ -h-o-t-m-a-i-l-c-o-m> ha
>> scritto
>> nel messaggio news:eHClqTZpGHA.756@TK2MSFTNGP05.phx.gbl...
>> > hi Steven, viewstate is already maintained by the individual controls
>> > that
>> > you are using (label, textbox). So in your text and title properties,
>> > get
>> > accessor, check if the text of both your label and textbox are not
>> > empty
>> > and if they are not then pull the values from here. Since you are
>> > inheriting CompositeControls, you shouldnt have a problem because it
>> > already ensures that CreateChildControls is already called prior to
>> > pulling the values from the controls.
>> > Also as you can see, your disabling viewstate on the textbox will
>> > produce
>> > an unwanted result since the textchanged event of the textbox will
>> > fire,
>> > regardless the text has changed or not. This is because since you
>> > disabled
>> > viewstate it does not compare old and new values, not being able to do
>> > so,
>> > it simply fires this event regardless.
>> >
>> > Regards,
>> > Alessandro Zifiglio
>> > http://www.AsyncUI.net
>> > "Steven" <steven***@gmail.com> ha scritto nel messaggio
>> > news:1152690634.983346.142530@i42g2000cwa.googlegroups.com...
>> >> Hello All,
>> >>
>> >> I have a fairly simple question regarding best practises for Composite
>> >> controls.
>> >>
>> >> If I want to save into ViewState the data from a postback to a
>> >> ChildControl, I set a property of the Composite Control. This can't be
>> >> done from the CreateChildControl class because the child controls are
>> >> not yet populated with the postback data at this point. I have
>> >> therefore being setting the property that will store this data into
>> >> view state in the event handler for the child control. I have provided
>> >> an example below where the postback data of a text control is saved to
>> >> a property of the Composite Control when the Event Handler of the
>> >> TextBox is called. Is this a suitable way to peform this or is there a
>> >> better practise to use?
>> >>
>> >>    public class CustomTextBox : CompositeControl
>> >>    {
>> >>        public event EventHandler TextChanged;
>> >>
>> >>        protected Label label;
>> >>        protected TextBox textBox;
>> >>
>> >>        public string Title
>> >>        {
>> >>            get { return (string)ViewState["Title"]; }
>> >>            set { ViewState["Title"] = value; }
>> >>        }
>> >>
>> >>        public string Text
>> >>        {
>> >>            get { return (string)ViewState["Text"]; }
>> >>            set { ViewState["Text"] = value; }
>> >>        }
>> >>
>> >>        protected override void CreateChildControls()
>> >>        {
>> >>            // Add the label
>> >>            label = new Label();
>> >>            label.EnableViewState = false;
>> >>            label.Text = Title;
>> >>            Controls.Add(label);
>> >>
>> >>            // Add the textbox
>> >>            textBox = new TextBox();
>> >>            textBox.EnableViewState = false;
>> >>            textBox.Text = Text;
>> >>            textBox.TextChanged += new EventHandler(OnTextChanged);
>> >>            Controls.Add(textBox);
>> >>        }
>> >>
>> >>        protected virtual void OnTextChanged(object sender, EventArgs
>> >> e)
>> >>        {
>> >>            if (TextChanged != null)
>> >>            {
>> >>                // Set the property of the Composite Control to store
>> >> the Text in ViewState
>> >>                Text = textBox.Text;
>> >>                TextChanged(this, e);
>> >>            }
>> >>        }
>> >>    }
>> >>
>> >
>> >
>