在C#中动态修改ConnectionStrings的内容，可以通过以下步骤实现：
using System.Configuration;
Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
ConnectionStringsSection connectionStringsSection = config.ConnectionStrings;
ConnectionStringSettings connectionString = connectionStringsSection.ConnectionStrings["MyConnectionString"];
connectionString.ConnectionString = "NewConnectionString";
config.Save(ConfigurationSaveMode.Modified);
总的来说，以上步骤将会帮助您在C#中动态修改ConnectionStrings的内容。
