Explorer view losing folder path information

Question

Hi all,

I am writing a custom webpart to replace SP's default ListWebPart in my document library view page. But I found it can't keep the folder information when showing the "Explorer View". For example, Ｉ enter a subfolder "root/folder 1" and select "Explorer View" in  ViewToolbar, it returns the root folders content. But when I click the "Open in Windows Explorer" in ActionMenu, it returns contents of folder 1.

I see the Sharepoint's ListViewWebpart does not have this problem. It can return correct contents when I enter a sub folder and click "Explorer View". The page's url contains correnct query strings about folder path (in my own webpart the query string is missing). Is it because I forget some config for the toolbar since I add it via codes?

Below is my code to add the toolbar:

 

     SPView view = this.CurrentView;

     if (view == null) return null;

    this._toolbar = new ViewToolBar();
    this._toolbar.ID = this.ID + "_ViewToolBar";
    this._toolbar.RenderContext = SPContext.Current;
    
    if (!String.IsNullOrEmpty(view.ToolbarTemplateName))
    {
     this._toolbar.TemplateName = view.ToolbarTemplateName;
    }
      
    return this._toolbar;

 

Thanks a lot.