Outlook插件仅读信时可用，撰写邮件时不可见，需适配双场景

你的插件在撰写新邮件时不可见，核心原因是manifest的基础配置部分仅声明了阅读场景的支持——尽管VersionOverrides里已经添加了撰写场景的命令栏扩展，但基础规则和表单设置限制了插件的加载范围。需要修改以下两处：

1. 补充撰写场景的表单设置 #

在<FormSettings>节点下添加<Form xsi:type="ItemCompose">配置，指定撰写场景的任务面板地址：

<FormSettings>
  <Form xsi:type="ItemRead">
    <DesktopSettings>
      <SourceLocation DefaultValue="https://localhost:3000/taskpane.html"/>
      <RequestedHeight>250</RequestedHeight>
    </DesktopSettings>
  </Form>
  <!-- 添加撰写场景配置 -->
  <Form xsi:type="ItemCompose">
    <DesktopSettings>
      <SourceLocation DefaultValue="https://localhost:3000/taskpane.html"/>
      <RequestedHeight>250</RequestedHeight>
    </DesktopSettings>
  </Form>
</FormSettings>

2. 扩展加载规则，包含撰写场景 #

修改<Rule>节点，添加FormType="Edit"的规则（对应邮件撰写/编辑场景）：

<Rule xsi:type="RuleCollection" Mode="Or">
  <Rule xsi:type="ItemIs" ItemType="Message" FormType="Read"/>
  <!-- 添加撰写场景规则 -->
  <Rule xsi:type="ItemIs" ItemType="Message" FormType="Edit"/>
</Rule>

修改后的完整manifest代码 #

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<OfficeApp xmlns="http://schemas.microsoft.com/office/appforoffice/1.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:bt="http://schemas.microsoft.com/office/officeappbasictypes/1.0" xmlns:mailappor="http://schemas.microsoft.com/office/mailappversionoverrides/1.0" xsi:type="MailApp">

  <Version>1.0.0.0</Version>
  <ProviderName>Contoso</ProviderName>
  <DefaultLocale>en-US</DefaultLocale>
  <DisplayName DefaultValue="Scout"/>
  <Description DefaultValue="A template to get started."/>
  <IconUrl DefaultValue="https://localhost:3000/assets/icon-64.png"/>
  <HighResolutionIconUrl DefaultValue="https://localhost:3000/assets/icon-128.png"/>
  <SupportUrl DefaultValue="https://www.contoso.com/help"/>
  <AppDomains>
    <AppDomain>https://www.contoso.com</AppDomain>
  </AppDomains>
  <Hosts>
    <Host Name="Mailbox"/>
  </Hosts>
  <Requirements>
    <Sets>
      <Set Name="Mailbox" MinVersion="1.1"/>
    </Sets>
  </Requirements>
  <FormSettings>
    <Form xsi:type="ItemRead">
      <DesktopSettings>
        <SourceLocation DefaultValue="https://localhost:3000/taskpane.html"/>
        <RequestedHeight>250</RequestedHeight>
      </DesktopSettings>
    </Form>
    <!-- 新增撰写场景表单配置 -->
    <Form xsi:type="ItemCompose">
      <DesktopSettings>
        <SourceLocation DefaultValue="https://localhost:3000/taskpane.html"/>
        <RequestedHeight>250</RequestedHeight>
      </DesktopSettings>
    </Form>
  </FormSettings>
  <Permissions>ReadWriteItem</Permissions>
  <Rule xsi:type="RuleCollection" Mode="Or">
    <Rule xsi:type="ItemIs" ItemType="Message" FormType="Read"/>
    <!-- 新增撰写场景加载规则 -->
    <Rule xsi:type="ItemIs" ItemType="Message" FormType="Edit"/>
  </Rule>
  <DisableEntityHighlighting>false</DisableEntityHighlighting>
  <VersionOverrides xmlns="http://schemas.microsoft.com/office/mailappversionoverrides" xsi:type="VersionOverridesV1_0">
    <Requirements>
      <bt:Sets DefaultMinVersion="1.3">
        <bt:Set Name="Mailbox"/>
      </bt:Sets>
    </Requirements>
    <Hosts>
      <Host xsi:type="MailHost">
        <DesktopFormFactor>
          <FunctionFile resid="Commands.Url"/>
          <ExtensionPoint xsi:type="MessageReadCommandSurface">
            <OfficeTab id="TabDefault">
              <Group id="msgReadGroup">
                <Label resid="GroupLabel"/>
                <Control xsi:type="Button" id="msgReadOpenPaneButton">
                  <Label resid="TaskpaneButton.Label"/>
                  <Supertip>
                    <Title resid="TaskpaneButton.Label"/>
                    <Description resid="TaskpaneButton.Tooltip"/>
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="Icon.16x16"/>
                    <bt:Image size="32" resid="Icon.32x32"/>
                    <bt:Image size="80" resid="Icon.80x80"/>
                  </Icon>
                  <Action xsi:type="ShowTaskpane">
                    <SourceLocation resid="Taskpane.Url"/>
                  </Action>
                </Control>
                <Control xsi:type="Button" id="ActionButton">
                  <Label resid="ActionButton.Label"/>
                  <Supertip>
                    <Title resid="ActionButton.Label"/>
                    <Description resid="ActionButton.Tooltip"/>
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="Icon.16x16"/>
                    <bt:Image size="32" resid="Icon.32x32"/>
                    <bt:Image size="80" resid="Icon.80x80"/>
                  </Icon>
                  <Action xsi:type="ExecuteFunction">
                    <FunctionName>action</FunctionName>
                  </Action>
                </Control>
              </Group>
            </OfficeTab>
          </ExtensionPoint>
           <ExtensionPoint xsi:type="MessageComposeCommandSurface">
            <OfficeTab id="TabDefault">
              <Group id="msgComposeCmdGroup">
                <Label resid="GroupLabel"/>
                <Control xsi:type="Button" id="msgComposeInsertGist">
                  <Label resid="TaskpaneButton.Label"/>
                  <Supertip>
                    <Title resid="TaskpaneButton.Label"/>
                    <Description resid="TaskpaneButton.Tooltip"/>
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="Icon.16x16"/>
                    <bt:Image size="32" resid="Icon.32x32"/>
                    <bt:Image size="80" resid="Icon.80x80"/>
                  </Icon>
                  <Action xsi:type="ShowTaskpane">
                    <SourceLocation resid="Taskpane.Url"/>
                  </Action>
                </Control>
                <Control xsi:type="Button" id="ActionButton">
                  <Label resid="ActionButton.Label"/>
                  <Supertip>
                    <Title resid="ActionButton.Label"/>
                    <Description resid="ActionButton.Tooltip"/>
                  </Supertip>
                  <Icon>
                    <bt:Image size="16" resid="Icon.16x16"/>
                    <bt:Image size="32" resid="Icon.32x32"/>
                    <bt:Image size="80" resid="Icon.80x80"/>
                  </Icon>
                  <Action xsi:type="ExecuteFunction">
                    <FunctionName>action</FunctionName>
                  </Action>
                </Control>
              </Group>
            </OfficeTab>
          </ExtensionPoint>
        </DesktopFormFactor>
      </Host>
    </Hosts>
    <Resources>
      <bt:Images>
        <bt:Image id="Icon.16x16" DefaultValue="https://localhost:3000/assets/icon-16.png"/>
        <bt:Image id="Icon.32x32" DefaultValue="https://localhost:3000/assets/icon-32.png"/>
        <bt:Image id="Icon.80x80" DefaultValue="https://localhost:3000/assets/icon-80.png"/>
      </bt:Images>
      <bt:Urls>
        <bt:Url id="Commands.Url" DefaultValue="https://localhost:3000/commands.html"/>
        <bt:Url id="Taskpane.Url" DefaultValue="https://localhost:3000/taskpane.html"/>
      </bt:Urls>
      <bt:ShortStrings>
        <bt:String id="GroupLabel" DefaultValue="Contoso Add-in"/>
        <bt:String id="TaskpaneButton.Label" DefaultValue="Show Taskpane"/>
        <bt:String id="ActionButton.Label" DefaultValue="Perform an action"/>
      </bt:ShortStrings>
      <bt:LongStrings>
        <bt:String id="TaskpaneButton.Tooltip" DefaultValue="Opens a pane displaying all available properties."/>
        <bt:String id="ActionButton.Tooltip" DefaultValue="Perform an action when clicked."/>
      </bt:LongStrings>
    </Resources>
  </VersionOverrides>
</OfficeApp>

修改完成后，重新部署插件，就能在阅读和撰写邮件场景下都看到并使用插件了。

内容的提问来源于stack exchange，提问作者dev.skas