Question

me again,

I have a current page containing a usercontrol which lists buildings.

Here is a screenshot: http://i40.tinypic.com/2eusoyt.png

Now, my mentor asked me to build a button which allows the user the make the page show the properties in 2 columns.

How did I try this?
I tried putting the following in my Page_load:

            if (ViewState["numberOfColumns"] != null)
            {
                numberOfColumns= Int32.Parse(ViewState["numberOfColumns"].ToString());

            }
            else
            {
                ViewState["numberOfColumns"] = 1;
                numberOfColumns= 1;
            }

Then behind the button view I put this code:

        protected void btnView_Click(object sender, EventArgs e)
    {
        switch(numberOfColumns)
        {
            case 1:
                numberOfColumns= 2;
                ViewState["numberOfColumns"] = numberOfColumns;

                break;
            case 2:
                numberOfColumns= 1;
                ViewState["numberOfColumns"] = numberOfColumns;
                break;
        }

    }

But as I guessed this method needs one postback to set the sessionvariable, and another one to execute the pageload with the latest value.

I know there should be “a proper way” of doing this, but I can’t find it.

Any direct you guys could point me would be greatly appreciated.

Thanks in advance, Christophe

Answer 1

Okay,

This is how I did it.

The method building the output of the user control was called directly after the snippet above. It’s called “GetProperties()”.

So the problem was/is that according to the page cycle, .net first executes the Page_Load, and as last the control events.

So what I did was put the call to getProperties() for the first time (when IsPostback = false) in an if. So when you visit the page once, it will load the method, and after that no longer.

So, then I put the methodcall in my button, because when you click the button IsPostback = true.

This worked. Snippets below:
protected void Page_Load(object sender, EventArgs e)
{
//some generic stuff

            if (!IsPostBack)
            {
                ViewState["kolommen"] = 1;
                AantalKolommen = 1;
                GetProperties(_tkth, _categorie, _verkochtverhuurd);
            }
        }

And behind the button I did the following:

        protected void btnView_Click(object sender, EventArgs e)
    {
        switch (Int32.Parse(ViewState["kolommen"].ToString()))
        {
            case 1:
                AantalKolommen = 2;
                ViewState["kolommen"] = 2;
                break;
            case 2:
                AantalKolommen = 1;
                ViewState["kolommen"] = 1;
                break;
        }
        GetProperties(_tkth, _categorie, _verkochtverhuurd);
    }

This works like a charm. Altho, I’d still like to know if this