如何用静态方法调用非静态方法（使用WebControl）？

Question

I have the following snippet of code. I can only access the PbcTreeView in a non-static method, so I call it during Page_Load. However, the setTreeView() method can't access the object b not can it call the buildTreeView() method. (setTreeView() has to be static according to the WebMethod rules and buildTreeView can't be static because it uses the TreeView). How could I get it to do something similar to b.buildTreeView() that I have in the method?

Thanks

protected void Page_Load(object sender, EventArgs e)
    {
        BuildPbcTree b = new BuildPbcTree(PbcTreeView);
    }

    [WebMethod]
    public static void setTreeView()
    {
        b.buildTreeView(); //how do I do this??
    }

    public class BuildTree
    {
        TreeView Tree;
        public BuildTree(TreeView t)
        {
            Tree = t;
        }
        public void buildTreeView() {...//implementation}
    }

Answer 1

You can pass the instance of the class to the Static method. For example, in your Page_Load:

SetTreeView(b);

This assumes you change your web method to accept a BuildTree class.

Answer 2

I assume that PbcTreeView is some control on your page.

In that case, you are out of luck. You cannot modify server-side controls during AJAX calls (web methods). AJAX calls are designed to be used as follows:

1. You call your web method in JavaScript code.
2. The web method performs some database lookup or computation and returns the result.
3. Your JavaScript code updates the user interface.

You are trying to update the user interface inside a web method. That won't work. If you need to do that, use a postback or an asynchronous postback with an UpdatePanel.