如何在app.config中使用数据目录设置连接字符串

Question

app。配置

<connectionStrings>
<add name="connect_string" providerName="System.Data.SqlClient" connectionString="Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\database.mdf;Integrated Security=True"/>

在c＃

AppDomain.CurrentDomain.SetData("DataDirectory", Environment.CurrentDirectory.Replace("\\bin\\Debug", ""));

public static void deleteitem(string name) {
 string connect_string = ConfigurationManager.ConnectionStrings["connect_string"].ConnectionString;

这是我的预期结果

  

数据源=（LocalDB）\ MSSQLLocalDB; AttachDbFilename = C：\ test \ database.mdf;集成安全性= True“ />

但这是我得到的结果

  

Data Source =（LocalDB）\ MSSQLLocalDB; AttachDbFilename = | DataDirectory | \ database.mdf; Integrated Security = True“

我的错误是什么