Custom selection extension
Config.esriaddinx
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 You may freely redistribute and use this sample code, with or
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<ESRI.Configuration xmlns="http://schemas.esri.com/Desktop/AddIns" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <Name>Selection Sample VB.NET</Name>
  <AddInID>{BB1BB09E-F0A3-42c3-A62D-3062464AE48A}</AddInID>
  <Description>A custom selection extension that includes new selection tools and a dockable window that reports the selection on a per layer basis.</Description>
  <Version>1.0</Version>
  <Image>Images\SelectionSample.png</Image>
  <Author>ESRI Staff</Author>
  <Company>ESRI</Company>
  <Date>10/8/2009</Date>
  <Targets>
    <Target name="Desktop" version="10.1" />
  </Targets>
  <AddIn language="CLR" library="SelectionSample.dll" namespace="SelectionSample">
    <ArcMap>
      <Commands>
        <Button id="ESRI_SelectionSample_ToggleDockWinBtn" class="ToggleDockWinBtn" caption="Toggle Dockable Window" category="Framework AddIn Samples" image="Images\ToggleDockWinBtn.png" tip="Toggle dockable window." message="Toggle dockable window.">
          <Help heading="Add-in button">Click on the button to toggle the dockable window with selected features count per layer.</Help>
        </Button>
        <Tool id="ESRI_SelectionSample_SelectByLineTool" class="SelectByLineTool" caption="Select By Line Tool" category="Framework AddIn Samples" image="Images\SelectByLine.png" cursor="Images\SelectByLine.cur" tip="Select By Line Tool." message="Select By Line Tool."></Tool>
        <ToolPalette id="ESRI_SelectionSample_ToolPalette" caption="Selection Palette" isMenuStyle="false" category="Framework AddIn Samples" >
          <Items>
            <Tool refID="esriArcMapUI.SelectByPolygonTool" />
            <Tool refID="esriArcMapUI.SelectByLayerCommand" />
            <Tool refID="ESRI_SelectionSample_SelectByLineTool" />
          </Items>
        </ToolPalette>
        <ComboBox id="ESRI_SelectionSample_SelectionTargetComboBox" class="SelectionTargetComboBox"
                  tip="Select the selectoin target." message="Select the selection target."
                  caption="Selection Target:" showCaption="false" category="Framework AddIn Samples" 
                  image="Images\SelectionTargetComboBox.png" editable="true" sizeString="WWWWWWWWWWWWWW"
                  rows="4" itemSizeString="WWWWWWWWWWWWWW" hintText="Selection target">
          <Help heading="Add-in ComboBox">Use this combo box to set the selection target.</Help>
        </ComboBox>
        <MultiItem id="ESRI_SelectionSample_MultiItem" caption="MultiItem AddIn" class="ZoomToLayerMultiItem" message="Select layer to zoom to its full extent.">
          <Help heading="Add-in MultiItem">Select layer to zoom to its full extent.</Help>
        </MultiItem>
      </Commands>
      <Extensions>
        <Extension id="ESRI_SelectionSample_SimpleExtension" autoLoad="false" productName="Selection Sample Extension" showInExtensionDialog="true" class="SelectionExtension">
          <Description>This is a selection sample extension.</Description>
        </Extension>
      </Extensions>
      <Toolbars>
        <Toolbar id="ESRI_SelectionSample_AddInToolbar" caption="Selection AddIn Toolbar" showInitially="true">
          <Items>
            <!--Reference to the custom combobox-->
            <ComboBox refID="ESRI_SelectionSample_SelectionTargetComboBox" separator="true"/>
            <!--Reference to the custom menu to provide access to the custom multiItem -->
            <Menu refID="ESRI_SelectionSample_ZoomToLayerMenu"/>
            <!--Reference to the custom button and tool-->
            <Button refID="ESRI_SelectionSample_ToggleDockWinBtn"/>
            <Tool refID="ESRI_SelectionSample_SelectByLineTool" />
            <!--Reference to the custom tool palette-->
            <ToolPalette refID="ESRI_SelectionSample_ToolPalette" separator="true" />
            <!--Reference to the custom Menu-->
            <Menu refID="ESRI_SelectionSample_AddInMenu" separator="true" />
          </Items>
        </Toolbar>
      </Toolbars>
      <Menus>
        <Menu id="ESRI_SelectionSample_AddInMenu" caption="Selection Tools Menu" isRootMenu="false">
          <Items>
            <!--Built in buttons-->
            <Button refID="esriArcMapUI.ClearSelectionCommand" />
            <Button refID="esriArcMapUI.SelectAllCommand" />
          </Items>
        </Menu>
        <Menu id="ESRI_SelectionSample_ZoomToLayerMenu" caption="Zoom To Layer">
          <Items>
            <MultiItem refID="ESRI_SelectionSample_MultiItem"/>
          </Items>
        </Menu>
      </Menus>
      <DockableWindows>
        <DockableWindow id="ESRI_SelectionSample_SelCountDockWin" class="SelCountDockWin+AddinImpl" caption="Selected Features Count" image="Images\ToggleDockWinBtn.png">
          <InitialPlacement height="300" width="300" state="pinned" position="right" neighbor="esriArcMapUI.TOCDockableWindow" />
        </DockableWindow>
      </DockableWindows>
    </ArcMap>
  </AddIn>
</ESRI.Configuration>