如何在 web.config 文件中写入连接字符串并从中读取？

Answer 1

添加引用添加

System.Configuration

:-

System.Configuration.ConfigurationManager.
    ConnectionStrings["connectionStringName"].ConnectionString;

您还可以更改 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>

Answer 2

Web.config:

<connectionStrings>
    <add name="ConnStringDb" connectionString="Data Source=localhost;
         Initial Catalog=DatabaseName; Integrated Security=True;" 
         providerName="System.Data.SqlClient" />
</connectionStrings>

c#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 { }

Answer 3

试试这个 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

<connectionStrings>
<add name="yourconnectinstringName" connectionString="Data Source= DatabaseServerName; Integrated Security=true;Initial Catalog= YourDatabaseName; uid=YourUserName; Password=yourpassword; " providerName="System.Data.SqlClient"/>
</connectionStrings >

Answer 4

你确定你的配置文件（web.config）在正确的位置并且连接字符串真的在（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。我总是会添加一个供应商名称

<connectionStrings>
  <add name="Dbconnection" 
       connectionString="Server=localhost; Database=OnlineShopping; 
       Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>

Answer 5

试试这个

var configuration = WebConfigurationManager.OpenWebConfiguration("~");
var section = (ConnectionStringsSection)configuration.GetSection("connectionStrings");
section.ConnectionStrings["MyConnectionString"].ConnectionString = "Data Source=...";
configuration.Save();

Answer 6

尝试使用

WebConfigurationManager

代替

ConfigurationManager

Answer 7

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 文件中获取配置部分详细信息。

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();  
    }  
}  

Answer 8

两种添加连接字符串的方式

如果您在安装 mssql 时设置了实例名称，请确保在您的 web.config 文件中正确提供实例名称

1. 打开你的 web.config 文件

Two ways of adding connection string

if you set up an instance name while installing mssql make sure to provide the instance name correctly in your web.config file
1. open your web.config file

  <connectionStrings>
    <add name ="EmployeeAppDB" 
         connectionString="Data Source=INSTANCE_NAME_HERE; <==========
         Initial Catalog=EmployeeDB;Integrated Security=true" 
         providerName="System.Data.SqlClient"/>
  </connectionStrings>

2. open your web.config file
if you're using the default insallation of mssql with no instance name

  <connectionStrings>
    <add name ="EmployeeAppDB" connectionString="Data Source=.; <=========
         Initial Catalog=EmployeeDB;Integrated Security=true" 
         providerName="System.Data.SqlClient"/>
  </connectionStrings>