The dropdown panel button is configured through the dropdownPanelButton tag. It takes effect only when the group's rowCount attribute value is no less than 2. This control is typically used to construct selection panels, as shown below:

Below details the attributes and functions of the <dropdownPanelButton>...</dropdownPanelButton> tag:

  
<group id="LineStyle" index="11" label="Line Style" image="../resources/Group/Icon/LayerStyle/LineStyle.png" 
		  visible="true" platform="All" rowCount="2">
	<dropdownPanelButton index="0" label="Line Symbol" image="../resources/MapView/Icon/LayerStyle/LineStyle/LineSymbol_32.png" 
	      onAction="CtrlActionMapLineSymbol" 
          screenTip="Sets the linestyle used by the line object in the current layer." 
          visible="true" style="BIG" directLoadCtrlAction="false" platform="All" language="All" />
</group> 
      

• id: Unique identifier of the dropdown panel control. dropdownPanelButtons from different config files will be merged based on this ID.
• index: Determines the sorting order of dropdown panels when multiple panels exist at the same level.
• label: Display name of the dropdown panel control.
• image: Icon displayed on the control, using relative paths to the application. Note: The image must reside on the same disk as the application.
• onAction: Specifies the action to execute when the control is clicked.
• screenTip: Tooltip text displayed when hovering over the control.
• screenTipImage: Image path (relative to application) for supplementary tooltip information.
• shortcutKey: Keyboard shortcut combination in the format: [Ctrl] + [Alt] + [Shift] + [KeyName].
• visible: Controls visibility (true: visible, false: hidden).
• style: Display style options: BIG (large icon with text below), MEDIUM (small icon with inline text), SMALL (icon only).
• platform: Supported OS platforms: All, Windows, or Linux.
• language: Supported language versions: ZH (Chinese), US (English), JA (Japanese), or All.