ADO.NET讀取配置文件

App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
      
    </startup>
  
  <connectionStrings>
    <add name="constr" connectionString="server=111,username=123"/>
  </connectionStrings>
  
</configuration>

　　調用方法

ConnectionStringSettings css = ConfigurationManager.ConnectionStrings["constr"];
string cs = css.ConnectionString;

ConfigurationManager 只會從exe的.config讀取。控制檯和winform當中的配置文件叫App.config asp.net中叫做web.config 不能創建多個config也不能創建多個AppSettings段