Based on the documentation of WebSplitter, there is no Width property available in the WebSplitter properties collection. However, it has Size property which gets or sets the size of WebSplitter (in pixel). Value type of this property is integer and the default value is 4.

Hope this helps.

Where do I set the size when I am using the WebPaneManager?

There is a splitter between pnNavTree and pnContent that I want to make 8px wide.

Below is a snippet of my .aspx form:

     <ISWebDesktop:WebDesktopManager ID="mainDesktop" runat="server" Height="100%" Width="100%" ViewStateStorage="None">
        <FrameStyle BackColor="WhiteSmoke">
        </FrameStyle>
        <Windows>
            <ISWebDesktop:WebDesktopWindow Name="wndMain" ControlBox="No" AllowClose="No" AllowMaximize="No"
                AllowMinimize="No" AllowResize="No" ShowInTaskBar="false" WindowState="Maximized"
                CaptionDisplayMode="Text">
                <ContentTemplate>
                    <ISWebDesktop:WebPaneManager ID="ctlPaneManager" runat="server" Height="100%" Width="100%"
                        ViewStateStorage="None" SkinID="DefaultPage">
                        <RootGroupPane Name="RootGroup">
                            <Panes>
                                <ISWebDesktop:WebPane ContentScrollable="False" Height="Custom" HeightValue="40px"
                                    Name="pnHeader" Text="Application Header">
                                    <ContentTemplate>
                                        <DT:ApplicationHeader ID="ctlAppHeader" runat="server" />
                                    </ContentTemplate>
                                    <ContentPadding Bottom="0px" Top="0px" />
                                </ISWebDesktop:WebPane>                           <ISWebDesktop:WebGroupPane GroupType="VerticalTile" Name="pnContentGroup">
                                    <Panes>
                                        <ISWebDesktop:WebPane Name="pnNavTree" AllowCollapse="Yes" AllowResize="Yes" ContentMode="UseIFrame"
                                            ContentScrollable="False" Text="Navigation Tree" Width="Custom" WidthValue="250px"
                                            Visible="False" ContentURL="~/NewNavigationTree.aspx">
                                        </ISWebDesktop:WebPane>
                                        <ISWebDesktop:WebPane ContentMode="UseIFrame" Name="pnContent">
                                        </ISWebDesktop:WebPane>
                                    </Panes>
                                </ISWebDesktop:WebGroupPane>

Thank you.

I tried to set the Width property of SplitterStyle collection in WebPaneManager with no luck. I will try to look for other alternatives as a solution.

Edited on January 31, 2012 10:43 PM
Reason: Update Solution

I’d like to suggest you to directly access the placeholder element of the splitter and set the width property of the element. OnInitialize client-side event of WebPaneManager is suitable to place the code which set the width of the splitter.

function WebPaneManager1_OnInitialize(controlId)
{
    var WebPaneManager1 = ISGetObject(controlId);
    var VSplitter = WebPaneManager1.Splitters[1].PlaceholderId;
    var elmVSplitter = document.getElementById(VSplitter);

    elmVSplitter.style.width = "12px";
            
    return true;
}

I enclosed one simple sample as attachment. Please have the sample evaluated on your and let me know whether it helps or not.

Edited on February 1, 2012 2:29 AM
Reason: Update Alternative Solution

You might want to try to set PaneSpacing property of PaneSettings. PaneSpacing specifies the spacing between each Pane in pixel. It has integer value type and 4 as the default value.

<ISWebDesktop:WebPaneManager ID="WebPaneManager1" runat="server" Height="100%" Width="100%">
    <RootGroupPane Name="RootGroupPane" Text="Root GroupPane">
        <Panes>
            <ISWebDesktop:WebPane Height="Custom" HeightValue="15%" Name="Header" Text="Header">
                ...
            </ISWebDesktop:WebPane>
            <ISWebDesktop:WebGroupPane GroupType="VerticalTile" Name="GroupContent" Text="Group Content">
                <Panes>
                    <ISWebDesktop:WebPane Name="Side" Text="Side" Width="Custom" WidthValue="15%" HeightValue="85%"
                        AllowCollapse="Yes">
                        ...
                    </ISWebDesktop:WebPane>
                    <ISWebDesktop:WebPane Name="Content" Text="Content">
                        ...
                    </ISWebDesktop:WebPane>
                </Panes>
            </ISWebDesktop:WebGroupPane>
        </Panes>
    </RootGroupPane>
    ...
    <PaneSettings PaneSpacing="10">
        ...
    </PaneSettings>
    ...
</ISWebDesktop:WebPaneManager>

Where can I find the "PaneSettings" properties documented?

Please follow the step by step below in order to find the “PaneSettings” in WebDesktop 3 Documentation.

1. Open WebDesktop 3 Documentation (please point your mouse to start > All Programs > Intersoft WebUI Studio 2011 R2 SP1 > WebUI Studio for ASP.NET > WebDesktop 3 > WebDesktop 3 Documentation).
   
2. After the documentation opened, browse through following path on the Contents tab: Help Viewer Home > WebDesktop > Server-side References > ISNet.WebUI.WebDesktop Assembly > ISNet.WebUI.WebDesktop Namespace > WebPaneSettings Class > WebPaneSettings Class Members.
   

Hope this helps.