如何在C#中更新app.config connectionstring数据源值?

时间:2011-08-24 11:20:31

标签: winforms c#-4.0 entity-framework-4 app-config configuration-files

Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
config.ConnectionStrings.ConnectionStrings["MyConnectionString",String.Format("DataSource={0};")].ConnectionString=textBox1.Text;
config.Save(ConfigurationSaveMode.Modified, true);
ConfigurationManager.RefreshSection("connectionStrings");

我在第二行遇到麻烦。我似乎无法使语法正确。如您所见,我只想更新DataSource值。例如,如果当前值为数据源= PC001 \ SQL2008EXPRESS ,我希望将其更新为客户端在textBox1中输入的内容。

编辑:示例ConnectionString

<add name="ERPDatabaseTables" connectionString="metadata=res://*/ERPTables.csdl|res://*/ERPTables.ssdl|res://*/ERPTables.msl;provider=System.Data.SqlClient;provider connection string=&quot;Data Source=PC001\SQL2008EXPRESS;Initial Catalog=MyDatabase.mdf;Integrated Security=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient"/>

所以想要仅更新数据源= PC001 \ SQL2008EXPRESS 部分

1 个答案:

答案 0 :(得分:12)

你真正想要的是:

Configuration config = 
    ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

// Because it's an EF connection string it's not a normal connection string
// so we pull it into the EntityConnectionStringBuilder instead
EntityConnectionStringBuilder efb = 
    new EntityConnectionStringBuilder(
        config.ConnectionStrings.ConnectionStrings["ERPDatabaseTables"]
            .ConnectionString);

// Then we extract the actual underlying provider connection string
SqlConnectionStringBuilder sqb = 
    new SqlConnectionStringBuilder(efb.ProviderConnectionString);

// Now we can set the datasource
sqb.DataSource = textBox1.Text;

// Pop it back into the EntityConnectionStringBuilder 
efb.ProviderConnectionString = sqb.ConnectionString;

// And update...
config.ConnectionStrings.ConnectionStrings["ERPDatabaseTables"]
    .ConnectionString = efb.ConnectionString;

config.Save(ConfigurationSaveMode.Modified, true);
ConfigurationManager.RefreshSection("connectionStrings");

这假设:

  1. 您的EF连接字符串存在于应用程序的配置文件

  2. 您可以参考System.Data.Entity