asp.net core发布到iis后出现An error oc

asp.net core发布到iis后出现错误，An error occurred while starting the application，站点启动不了，这个提示很难发现问题的所在。

错误原文如下：

An error occurred while starting the application.

NET Core 4.6.26328.01 X64 v4.0.0.0 | Microsoft.AspNetCore.Hosting version 2.2.7-rtm-10026 | Microsoft Windows 10.0.16299 | Need help?

解决问题的第一步肯定是先找到错误原因，

解决办法，先打开iis日志。web.config 修改如下

    <aspNetCore requestTimeout="23:00:00" processPath="dotnet" arguments=".\XX.Web.dll" forwardWindowsAuthToken="false" stdoutLogEnabled="false" stdoutLogFile=".\logs\stdout" startupTimeLimit="3600">
      <environmentVariables /> 
    </aspNetCore>

需要把stdoutLogEnabled值false设置为true

如果没有发现该节点就复制一份过去, 记得把XX.Web.dll改成自己的名字。

<aspNetCore processPath="dotnet" arguments=".\XX.Web.dll" stdoutLogEnabled="true" stdoutLogFile=".\logs\stdout" hostingModel="inprocess" >
<environmentVariables>
<environmentVariable name="ASPNETCORE_ENVIRONMENT" value="Development" />
</environmentVariables>
</aspNetCore>

完成的config文件

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <system.webServer>
    <modules>
      <!-- Remove WebDAV module so that we can make DELETE requests -->
      <remove name="WebDAVModule" />
    </modules>
    <handlers>
      <!-- Remove WebDAV module so that we can make DELETE requests -->
      <remove name="WebDAV" />
      <add name="aspNetCore" path="*" verb="*" modules="AspNetCoreModule" resourceType="Unspecified" />
    </handlers>
    <!-- When deploying on Azure, make sure that "dotnet" is installed and the path to it is registered in the PATH environment variable or specify the full path to it -->
    <!-- 注意，修改这里/ -->
    <aspNetCore requestTimeout="23:00:00" processPath="dotnet" arguments=".\XX.Web.dll" forwardWindowsAuthToken="false" stdoutLogEnabled="true" stdoutLogFile=".\logs\stdout" startupTimeLimit="3600">
      <environmentVariables />
    </aspNetCore>
    <httpProtocol>
      <customHeaders>
        <remove name="X-Powered-By" />
        <!-- Protects against XSS injections. ref.: https://www.veracode.com/blog/2014/03/guidelines-for-setting-security-headers/ -->
        <add name="X-XSS-Protection" value="1; mode=block" />
        <!-- Protects against Clickjacking attacks. ref.: http://stackoverflow.com/a/22105445/1233379 -->
        <add name="X-Frame-Options" value="SAMEORIGIN" />
        <!-- Protects against MIME-type confusion attack. ref.: https://www.veracode.com/blog/2014/03/guidelines-for-setting-security-headers/ -->
        <add name="X-Content-Type-Options" value="nosniff" />
        <!-- Protects against Clickjacking attacks. ref.: https://www.owasp.org/index.php/HTTP_Strict_Transport_Security_Cheat_Sheet -->
        <add name="Strict-Transport-Security" value="max-age=31536000; includeSubDomains" />
        <!-- CSP modern XSS directive-based defence, used since 2014. ref.: http://content-security-policy.com/ -->
        <add name="Content-Security-Policy" value="default-src 'self'; connect-src * data:; font-src *; frame-src *; img-src * data:; media-src *; object-src *; script-src * 'unsafe-inline' 'unsafe-eval'; style-src * 'unsafe-inline'; worker-src blob:" />
        <!-- Prevents from leaking referrer data over insecure connections. ref.: https://scotthelme.co.uk/a-new-security-header-referrer-policy/ -->
        <add name="Referrer-Policy" value="strict-origin" />
        <!--Feature-Policy is a new header that allows a site to control which features and APIs can be used in the browser. ref.: https://wicg.github.io/feature-policy/ -->
        <add name="Feature-Policy" value="accelerometer 'none'; camera 'none'; geolocation 'none'; gyroscope 'none'; magnetometer 'none'; microphone 'none'; payment *; usb 'none'" />
      </customHeaders>
    </httpProtocol>
    <security>
      <requestFiltering>
        <!--文件上传限制-->
        <requestLimits maxAllowedContentLength="1073741822" />
        <!-- 1GB-->
      </requestFiltering>
    </security>
  </system.webServer>
</configuration>
<!--ProjectGuid: 4f1f649c-1020-45be-a487-f416d9297ff3-->

修改了再次启动网站，就会找到错误，定位到错误了改起来就简单了！！

结束！！