CODEWITHSUNDEEP
c#htmluser-controlsstaticnullreferenceexception
Adrian Bonnici
Adrian Bonnici

Reputation: 283

div runat="server" null reference exception in static method

I have a div in an aspx page which is set to runat server.

<div class="article-container" runat="server" id="divArticleContainer"></div>

Now this div is going to have a user control added to it through a static method:

public static void LoadCurrentArticle(int index)
    {
        divArticleContainer.Controls.Clear();
        Page pg = new Page();
        string path = @"/Frontend/Controls/Article/ArticleItem.ascx";
        ArticleItem control = (ArticleItem)pg.LoadControl(path);
        control.Functionality.article = Functionality.articles.ElementAt(index);
        divArticleContainer.Controls.Add(control);
    }

Basically to give you a brief overview my program is loading a list of news articles. On a touch gesture (swipe left or right) an ajax call to a web method GetNext() and GetPrevious() will move either to the next item or previous item in the list.

[WebMethod]
    public static void GetNext(int index)
    {
        int idx = index;
        idx++;
        if (idx < Functionality.articles.Count())
        {
            LoadCurrentArticle(idx);
            Functionality.index = idx;
        }
        else
        {
            idx = 0;
            LoadCurrentArticle(idx);
            Functionality.index = idx;
        }
    }

    [WebMethod]
    public static void GetPrevious(int index)
    {
        int idx = index;
        idx--;
        if (idx >= 0)
        {
            LoadCurrentArticle(idx);
            Functionality.index = idx;
        }
        else
        {
            idx = Functionality.articles.Count() - 1;
            LoadCurrentArticle(idx);
            Functionality.index = idx;
        }
    }

My MAIN problem is the fact that the 'divArticleWrapper' is returning a null reference exception. Is there a work around to this problem? enter image description here

Upvotes: 2

Views: 1284

Answers (1)

Pranay Rana
Pranay Rana

Reputation: 176896

In Static method you cannot access the page controls divArticleWrapper ...

you cant access nonstatic controls from a static method.

static methods can access static variables only..

EDIT

Static methods cannot access instance state (such as a non-static control). Either remove static from the method declaration, or pass a reference to the control as argument to the method:

private static void YourStaticMethod(HtmlControl div) 
{    
 //than do your task
}

...and call it like so:

YourStaticMethod(divArticleWrapper);

Upvotes: 4

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