[英]How to write connection string in web.config file and read from it?
我正在尝试像这样将连接字符串写入 Web.config:
<connectionStrings>
<add name="Dbconnection" connectionString="Server=localhost;
Database=OnlineShopping ; Integrated Security=True"/>
</connectionStrings >
并像这样阅读它:
string strcon =
ConfigurationManager.ConnectionStrings["Dbconnection"].ConnectionString;
SqlConnection DbConnection = new SqlConnection(strcon);
运行程序时,由于空引用而出现错误。 但是当我使用此代码时:
SqlConnection DbConnection = new SqlConnection();
DbConnection.ConnectionString =
"Server=localhost; Database=OnlineShopping ; Integrated Security=True";
我没有收到任何错误,程序正常运行! 问题是什么?
添加引用以添加System.Configuration
:-
System.Configuration.ConfigurationManager.
ConnectionStrings["connectionStringName"].ConnectionString;
您也可以更改 WebConfig 文件以包含提供程序名称:-
<connectionStrings>
<add name="Dbconnection"
connectionString="Server=localhost; Database=OnlineShopping;
Integrated Security=True"; providerName="System.Data.SqlClient" />
</connectionStrings>
网页配置:
<connectionStrings>
<add name="ConnStringDb" connectionString="Data Source=localhost;
Initial Catalog=DatabaseName; Integrated Security=True;"
providerName="System.Data.SqlClient" />
</connectionStrings>
代码:
using System.Configuration;
using System.Data
SqlConnection _connection = new SqlConnection(
ConfigurationManager.ConnectionStrings["ConnStringDb"].ToString());
try
{
if(_connection.State==ConnectionState.Closed)
_connection.Open();
}
catch { }
您确定您的配置文件 (web.config) 位于正确的位置并且连接字符串确实在(生成的)文件中吗? 如果您发布文件,则可能会复制 web.release.config 的内容。
配置和对连接字符串的访问在我看来没问题。 我总是会添加一个提供者名称
<connectionStrings>
<add name="Dbconnection"
connectionString="Server=localhost; Database=OnlineShopping;
Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>
在应用程序中打开 web.config 文件并像这样在 connectionStrings 部分添加示例数据库连接后试试这个
<connectionStrings>
<add name="yourconnectinstringName" connectionString="Data Source= DatabaseServerName; Integrated Security=true;Initial Catalog= YourDatabaseName; uid=YourUserName; Password=yourpassword; " providerName="System.Data.SqlClient"/>
</connectionStrings >
试试这个
var configuration = WebConfigurationManager.OpenWebConfiguration("~");
var section = (ConnectionStringsSection)configuration.GetSection("connectionStrings");
section.ConnectionStrings["MyConnectionString"].ConnectionString = "Data Source=...";
configuration.Save();
尝试使用WebConfigurationManager
而不是ConfigurationManager
在应用程序中打开 web.config 文件后,在 connectionStrings 部分添加示例数据库连接,如下所示:
<connectionStrings>
<add name="yourconnectinstringName" connectionString="Data Source= DatabaseServerName; Integrated Security=true;Initial Catalog= YourDatabaseName; uid=YourUserName; Password=yourpassword; " providerName="System.Data.SqlClient" />
</connectionStrings>
在 web.config 文件中声明 connectionStrings:
<add name="dbconnection" connectionString="Data Source=Soumalya;Integrated Security=true;Initial Catalog=MySampleDB" providerName="System.Data.SqlClient" />
无需用户名和密码即可访问数据库服务器。 现在,编写代码以从我们的代码隐藏文件中的 web.config 文件中获取连接字符串。 在代码隐藏文件中添加以下命名空间。
using System.Configuration;
此命名空间用于从 web.config 文件中获取配置节详细信息。
using System;
using System.Data.SqlClient;
using System.Configuration;
public partial class _Default: System.Web.UI.Page {
protected void Page_Load(object sender, EventArgs e) {
//Get connection string from web.config file
string strcon = ConfigurationManager.ConnectionStrings["dbconnection"].ConnectionString;
//create new sqlconnection and connection to database by using connection string from web.config file
SqlConnection con = new SqlConnection(strcon);
con.Open();
}
}
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