Monthly Archives: December 2009

Middle-click in Far Manager 2

Software

In Far Manager 1.70 you could browse folders with mouse wheel. Rotating wheel would scroll up and down. Middle-click would open a folder. But version 2.0 disables middle-click. Boo! Never take away features from users.

Mouse wheel

Fortunately it’s very easy to restore this functionality:

  1. Launch [C:\Program Files\Far2\Addons\Macros\MiddleClickAsEnter.reg]. If you don’t have this folder re-install Far and add Addons » Macros feature.
  2. Restart Far Manager.

How to add context menu to Far Manager

Software

Sometimes I need to do something with file that Far Manager can’t help me with. Good example is changing file permissions. In these cases Windows Explorer context menu comes handy:

far-context-menu

If you want context menu in Far Manager you need EMenu plugin. Fortunately, it is included with Far by default. Here’s how to set it up:

  1. Execute [C:\Program Files\Far\Plugins\EMenu\Hotkey.reg]
  2. Restart Far Manager
  3. Open Options menu, then Plugins configuration. Select EMenu in the list.
  4. Uncheck “Show message after execution”.

Now Menu key should invoke context menu. Nice trick is to select Send To – Mail Recipient to quickly open new email with the file attached.

How to use ClientScriptManager.RegisterForEventValidation method

Develop

Have you ever encountered this error:

Invalid postback or callback argument.  Event validation is enabled using <pages enableEventValidation=”true”/> in configuration or <%@ Page EnableEventValidation=”true” %> in a page.  For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them.  If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

That’s pretty long error message. I get this exception if I add items to drop-down control from JavaScript. The question is how to use ClientScriptManager.RegisterForEventValidation method?

First, let’s reproduce the problem. Create a new website and copy/paste this code:

<asp:DropDownList ID="dd" runat="server">
  <asp:ListItem>One</asp:ListItem>
  <asp:ListItem>Two</asp:ListItem>
</asp:DropDownList>
<asp:Button ID="Button1" runat="server" Text="Test" />

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.3.2/jquery.min.js"
  type="text/javascript"></script>
<script type="text/javascript">
  $(function()
  {
    $("#<%= dd.ClientID %>").append($("<option />")
      .val(3)
      .text("Three!"));
  });
</script>

If you select option “Three” sure enough, exception is thrown. To prevent it you need to supply all possible values for drop-down control:

protected override void Render(HtmlTextWriter writer)
{
  Page.ClientScript.RegisterForEventValidation(dd.UniqueID, "3");
  Page.ClientScript.RegisterForEventValidation(dd.UniqueID, "4");
  Page.ClientScript.RegisterForEventValidation(dd.UniqueID, "11");
  // and so on
  base.Render(writer);
}

The exception is fixed but server variable for drop-down control is useless – it has no idea that you’ve added new item so dd.SelectedValue will give One, not 3. You need to read POST variable directly instead, like this:

protected void Page_Load(object sender, EventArgs e)
{
   if (IsPostBack)
      Response.Write(Request.Form[dd.UniqueID]);
}