I have a TreeView control with checkboxes in a page that posts back. If the user then clicks the browser's back button the TreeView control is back in it's original state, it doesn't keep the items selected that the user selected. Is there a way to accomplish this?

Many Thanks,
Ken

Hi,

Would it be feasible to use the TreeView's client-side API to scrape the state of the TreeView into a hidden form field onsubmit and then on page load take the state out of the hidden form field and use the API to select the correct checkboxes? Or is there a known problem with this approach?

Thanks,
Ken

Hi,

I've succeeded (at least in my target browser IE). I don't need to detect the back button click. I have two javascript functions. The first runs in response to the window.onload event. It looks at a hidden form field, if the field has data in it then the function deserializes it into an object which represents the last state of the TreeView control when the page was submitted and then uses the TreeView client API to rehydrate the appropriate check boxes in the TreeView.

I have another function which executes with the forms onsubmit event. It gets the checked nodes from the TreeView client API, puts this data into an object and then serializes that object to a JSON string and puts it into the hidden form field. This form field is submitted, but the server code ignores the hidden form field. However when you click the back button the browser repopulates form fields (including hidden form fields) with the data they contained when submitted. Thus the state of the TreeView is preserved. The window.onload function reads the data and restores the TreeView state.

Thanks,
Ken