C#书店管理、收银系统（完整源码）

<?xml version='1.0' encoding='utf-8'?> <SettingsFile xmlns="http://schemas.microsoft.com/VisualStudio/2004/01/settings" CurrentProfile="(Default)" GeneratedClassNamespace="书店零售系统.Properties" GeneratedClassName="Settings"> <Profiles /> <Settings> <Setting Name="BookStoreConnectionString" Type="(Connection string)" Scope="Application"> <DesignTimeValue Profile="(Default)">&lt;?xml version="1.0" encoding="utf-16"?&gt; &lt;SerializableConnectionString xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"&gt; &lt;ConnectionString&gt;Data Source=ANGLE-PC;Initial Catalog=BookStore;Persist Security Info=True;User ID=sa;Password=123&lt;/ConnectionString&gt; &lt;ProviderName&gt;System.Data.SqlClient&lt;/ProviderName&gt; &lt;/SerializableConnectionString&gt;</DesignTimeValue> <Value Profile="(Default)">Data Source=ANGLE-PC;Initial Catalog=BookStore;Persist Security Info=True;User ID=sa;Password=123</Value> </Setting> </Settings> </SettingsFile>