部署Blazor WebAssembly后API无响应问题求助

• 应用：Blazor Web Assembly PWA，基于.NET 6.0
• API：Rest Api .NET Core，基于.NET 5.0
• WEB地址：localtesting.mydomain.com
• API地址：localtesting.mydomain.com/api（虚拟目录）

创建虚拟目录并上传API后可正常运行，但将Blazor WASM上传至根目录后API停止响应，推测是Blazor的web.config重写规则导致URL被重定向。修改web.config未解决问题，需添加规则避免API请求被拦截。

当前web.config内容：

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.webServer>
    <staticContent>
      <remove fileExtension=".blat" />
      <remove fileExtension=".dat" />
      <remove fileExtension=".dll" />
      <remove fileExtension=".json" />
      <remove fileExtension=".wasm" />
      <remove fileExtension=".woff" />
      <remove fileExtension=".woff2" />
      <mimeMap fileExtension=".blat" mimeType="application/octet-stream" />
      <mimeMap fileExtension=".dll" mimeType="application/octet-stream" />
      <mimeMap fileExtension=".dat" mimeType="application/octet-stream" />
      <mimeMap fileExtension=".json" mimeType="application/json" />
      <mimeMap fileExtension=".wasm" mimeType="application/wasm" />
      <mimeMap fileExtension=".woff" mimeType="application/font-woff" />
      <mimeMap fileExtension=".woff2" mimeType="application/font-woff" />
    </staticContent>
    <httpCompression>
      <dynamicTypes>
        <add mimeType="application/octet-stream" enabled="true" />
        <add mimeType="application/wasm" enabled="true" />
      </dynamicTypes>
    </httpCompression>
    <rewrite>
      <rules>
        <rule name="Serve subdir">
          <match url=".*" />
          <action type="Rewrite" url="wwwroot\{R:0}" />
        </rule>
        <rule name="SPA fallback routing" stopProcessing="true">
          <match url=".*" />
          <conditions logicalGrouping="MatchAll">
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
          </conditions>
          <action type="Rewrite" url="wwwroot\" />
        </rule>
      </rules>
    </rewrite>
  </system.webServer>
</configuration>

相关截图说明：

• 未发布Blazor WebAssembly时的API响应
• Plesk上上传Blazor WebAssembly后的状态
• 上传Blazor WebAssembly后的情况
• 无数据状态

在web.config的rewrite规则最顶部添加一条跳过API路径的规则，让所有以/api开头的请求直接跳过重写，交给虚拟目录处理：

修改后的web.config：

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
  <system.webServer>
    <staticContent>
      <remove fileExtension=".blat" />
      <remove fileExtension=".dat" />
      <remove fileExtension=".dll" />
      <remove fileExtension=".json" />
      <remove fileExtension=".wasm" />
      <remove fileExtension=".woff" />
      <remove fileExtension=".woff2" />
      <mimeMap fileExtension=".blat" mimeType="application/octet-stream" />
      <mimeMap fileExtension=".dll" mimeType="application/octet-stream" />
      <mimeMap fileExtension=".dat" mimeType="application/octet-stream" />
      <mimeMap fileExtension=".json" mimeType="application/json" />
      <mimeMap fileExtension=".wasm" mimeType="application/wasm" />
      <mimeMap fileExtension=".woff" mimeType="application/font-woff" />
      <mimeMap fileExtension=".woff2" mimeType="application/font-woff" />
    </staticContent>
    <httpCompression>
      <dynamicTypes>
        <add mimeType="application/octet-stream" enabled="true" />
        <add mimeType="application/wasm" enabled="true" />
      </dynamicTypes>
    </httpCompression>
    <rewrite>
      <rules>
        <!-- 跳过API路径的重写，直接交由虚拟目录处理 -->
        <rule name="Skip API Requests" stopProcessing="true">
          <match url="^api/(.*)" />
          <action type="None" />
        </rule>
        <rule name="Serve subdir">
          <match url=".*" />
          <action type="Rewrite" url="wwwroot\{R:0}" />
        </rule>
        <rule name="SPA fallback routing" stopProcessing="true">
          <match url=".*" />
          <conditions logicalGrouping="MatchAll">
            <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
          </conditions>
          <action type="Rewrite" url="wwwroot\" />
        </rule>
      </rules>
    </rewrite>
  </system.webServer>
</configuration>

规则说明 #

• 新增的Skip API Requests规则会匹配所有以api/开头的URL，stopProcessing="true"确保匹配后不再执行后续重写规则，直接将请求传递给对应的虚拟目录。
• 该规则必须放在所有重写规则的最前面，保证API请求优先被识别。

内容的提问来源于stack exchange，提问作者H.M.Mubashir