How to validate ConnectionString exists and if not do not throw error

The connection name 'MySqlServer' was not found in the applications configuration or the connection string is empty.

So, I have a page with a panel that will display when the connection in the web config is found and the connection is valid; using a try/catch as long as the add name"VALUE" is in the config connection strings if the server data is bad the page will load and the panel is set to invisible... I need to be able to handle the following...

If the named value in this case MySqlServer is used in the aspx; aspx.cs but not found in the config I do not want the error to occur; connection name was not found.... I just want to not show the panel like when the SqlConnection.Open fails when the name is found but data is bad...

aspx

   <asp:SqlDataSource runat="server" ID="allowedIPsSqlDataSource" 
    ConnectionString="<%$ ConnectionStrings:MySqlServer %>"

aspx.cs

string connectionString = ConfigurationManager.ConnectionStrings["MySqlServer"].ToString();
        SqlConnection SqlConnection = new SqlConnection(connectionString);
        SqlCommand SqlCommand = new SqlCommand();
        try
        {
            SqlConnection.Open();

config

<connectionStrings>
        <add name="NotMySqlServer" providerName="System.Data.SqlClient" connectionString="server=TEST\SQL2005;database=ADB;Integrated Security=True"/>
<add name="NotMy2SqlServer" providerName="System.Data.SqlClient" connectionString="server=TEST\SQL2005;database=ADB;Integrated Security=True"/>

    </con开发者_运维技巧nectionStrings>

You can try :

if(ConfigurationManager.ConnectionStrings["MySqlServer"] == null) throw ...

If you're using .NET 4.5+ and have access to C# 6.0, you can make use of the null conditional operator (?) to try and get the connection string without automatically throwing an exception:

string connectionString = ConfigurationManager.ConnectionStrings["MySqlServer"]?.ConnectionString;
//------------------------------------------------------------------------HERE-^-HERE-------------

if (string.IsNullOrWhiteSpace(connectionString))
{
    // Don't even bother trying to open the connection.
    // Log the error and either rethrow the exception (throw;) or exit from your current context (return;).
    //return;
    //throw;
}

// If your code has made it this far, it means you have a valid connection string.  Now try to use it.
using (var sqlConnection = new SqlConnection(connectionString))
{
    sqlConnection.Open();

    using (var sqlCommand = new SqlCommand)
    {
        // Do stuff.
    }
}

You can check if there are any connections strings by using count.

var count = ConfigurationManager.ConnectionStrings.Count;
if (count > 0)
{
    //There is at least more then one connection string.
}

Update

public static class Extension
{
    public static bool HasConnectionString(this ConnectionStringSettingsCollection value, string key)
{
    try
    {
        return value[key].ConnectionString.Length > 0;
    }catch 
    {
        return false;
    }
}
}

You can use the extension as follow.

if (ConfigurationManager.ConnectionStrings.HasConnectionString("MySqlServer"))
{
    //If true you know there is a valid connectionstring.
}