c# - How to render a control to look like ComboBox with Visual Styles enabled?


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I have a control that is modelled on a ComboBox. I want to render the control so that the control border looks like that of a standard Windows ComboBox. Specifically, I have followed the MSDN documentation and all the rendering of the control is correct except for rendering when the control is disabled.

Just to be clear, this is for a system with Visual Styles enabled. Also, all parts of the control render properly except the border around a disabled control, which does not match the disabled ComboBox border colour.

I am using the VisualStyleRenderer class. MSDN suggests using the VisualStyleElement.TextBox element for the TextBox part of the ComboBox control but a standard disabled TextBox and a standard disabled ComboBox draw slightly differently (one has a light grey border, the other a light blue border).

How can I get correct rendering of the control in a disabled state?


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    I'm not 100% sure if this is what you are looking for but you should check out the VisualStyleRenderer in the System.Windows.Forms.VisualStyles-namespace.

    1. VisualStyleRenderer class (MSDN)
    2. How to: Render a Visual Style Element (MSDN)
    3. VisualStyleElement.ComboBox.DropDownButton.Disabled (MSDN)

    Since VisualStyleRenderer won't work if the user don't have visual styles enabled (he/she might be running 'classic mode' or an operative system prior to Windows XP) you should always have a fallback to the ControlPaint class.

    // Create the renderer.
    if (VisualStyleInformation.IsSupportedByOS 
        && VisualStyleInformation.IsEnabledByUser) 
    {
        renderer = new VisualStyleRenderer(
            VisualStyleElement.ComboBox.DropDownButton.Disabled);
    }
    

    and then do like this when drawing:

    if(renderer != null)
    {
        // Use visual style renderer.
    }
    else
    {
        // Use ControlPaint renderer.
    }
    

    Hope it helps!


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    Are any of the ControlPaint methods useful for this? That's what I usually use for custom-rendered controls.