C # WinForm Program app.config database connection configuration file use process

App.config "Application configuration file", it is actually a standard XML file, but. NET class library has encapsulated the method of reading this file. can be very convenient to use. Look at the use process.

1. Right-click your project name in Solution Explorer, add > New Item, select application configuration file in the list, and the default file is app.config. Are you sure.

2. Open app.config, the initial XML code is:

<xml version= "1.0" encoding= "Utf-8" >  
<configuration>  
</configuration>

Set your connection string in the following format

<xml version= "1.0" encoding= "Utf-8" >  
<configuration>  
    <connectionStrings>  
        <!-- The server here can write (local) or write a dot .-->  
        <add name= "sqlconnstring connectionstring=" server=.; database= database name; uid= user name; pwd= password "  />  
    </connectionStrings>  
</configuration>

Where name is the identity name of the connection string (similar to an alias). ConnectionString is your connection string. You can write multiple add nodes.

Note: The format is fixed

3. Right-click "Reference" in your project in Solution Explorer, add System.Configuration Reference. In your code, you need both:

Using System.Configuration;

4. began to acquire the

String connstr= configurationmanager.connectionstrings["MyConn"]. ConnectionString;  
 SqlConnection cn = new SqlConnection (CONNSTR);  
 cn. Open ();

At this point the database is open, you can write the appropriate code