ef(EntityFramework)动态传递数据库连接字符串

1.使用entityConnectionStringBuilder 创建连接字符串

public static string GetConnStr(string host, string catalog, string user, string pass, bool winAuth=false)
        {
            SqlConnectionStringBuilder sqlBuilder = new SqlConnectionStringBuilder
            {
                DataSource = host,
                InitialCatalog = catalog,
                PersistSecurityInfo = true,
                IntegratedSecurity = winAuth,
                MultipleActiveResultSets = true,

                UserID = user,
                Password = pass,
            };

            // assumes a connectionString name in .config of MyDbEntities
            var entityConnectionStringBuilder = new EntityConnectionStringBuilder
            {
                Provider = "System.Data.SqlClient",
                ProviderConnectionString = sqlBuilder.ConnectionString,
                Metadata = "res://*/FaceDB.csdl|res://*/FaceDB.ssdl|res://*/FaceDB.msl",  //此处需修改为正确的字符(观察并复制web.config中的即可)
            };

            return  entityConnectionStringBuilder.ConnectionString;
        }

将此方法返回的字符串传递进一个参数的构造函数实例化datacontext:参考http://www.voidcn.com/article/p-fllvvzft-btb.html

FaceEntities dc = new FaceEntities(GetConnStr(xxxx,xxx,xx,xx)); 

2.写死字符串模板并动态替换

public static string connTemplate = "metadata=res://*/FaceDB.csdl|res://*/FaceDB.ssdl|res://*/FaceDB.msl;provider=System.Data.SqlClient;provider connection string=\"Data Source = {{DBIp}}; Initial Catalog ={{DBName}}; Integrated Security = False; Persist Security Info=True;User ID = {{DBUser}}; Password={{DBPwd}};MultipleActiveResultSets=True\"";

也需注意metadata里的值修改.(观察并复制web.config中的即可)

 var connString = connTemplate.Replace("{{DBIp}}","192.168.x.x").Replace("{{DBName}}", "FaceDB").Replace("{{DBUser}}","sa").Replace("{{DBPwd}}","sa");

FaceEntities dc = new FaceEntities(connString);

 

3.读取原connectionstring再替换

public static string GetConnectionString()
{
var connectString = ConfigurationManager.ConnectionStrings["YourConnKey"].ConnectionString;
//解析connectString 替换ip,user,pwd,dbname等

connectString =替换后的string
return connectString;
}

 

From:https://www.cnblogs.com/xuejianxiyang/p/12175719.html