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DbConnectionStringBuilder.TryGetValue Method

Note: This method is new in the .NET Framework version 2.0.

Retrieves a value corresponding to the supplied key from this DbConnectionStringBuilder.

Namespace: System.Data.Common
Assembly: System.Data (in system.data.dll)

public virtual bool TryGetValue (
	string keyword,
	out Object value
)
public boolean TryGetValue (
	String keyword, 
	/** @attribute OutAttribute() */ /** @ref */ Object value
)
JScript does not support passing value-type arguments by reference.

Parameters

keyword

The key of the item to retrieve.

value

The value corresponding to the key.

Return Value

true if keyword was found within the connection string, false otherwise.

Exception typeCondition

ArgumentNullException

keyword contains a null value (Nothing in Visual Basic).

The TryGetValue method lets developers safely retrieve a value from a DbConnectionStringBuilder without needing to first call the ContainsKey method. Because TryGetValue does not raise an exception when you call it, passing in a nonexistent key, you do not have to look for a key before retrieving its value. Calling TryGetValue with a nonexistent key will place the null value (Nothing in Visual Basic) in the value parameter.

The following example calls the TryGetValue method, demonstrating several possible outcomes.

static void Main()
{
    DbConnectionStringBuilder builder = new DbConnectionStringBuilder();
    builder.ConnectionString = 
        "Provider=sqloledb;Data Source=192.168.168.1,1433;" +
        "Network Library=DBMSSOCN;Initial Catalog=pubs;" +
        "Integrated Security=SSPI;";

    // Call TryGetValue method for multiple
    // key names.
    DisplayValue(builder, "Provider");
    DisplayValue(builder, "DATA SOURCE");
    DisplayValue(builder, "InvalidKey");
    DisplayValue(builder, null);

    Console.ReadLine();


private static void DisplayValue(
    DbConnectionStringBuilder builder, string key)
{
    object value = null;

    // Although TryGetValue handles missing keys,
    // it doesn't handle passing in a null 
    // key. This example traps for that particular error, but
    // bubbles any other unknown exceptions back out to the
    // caller. 
    try
    {
        if (builder.TryGetValue(key, out value))
        {
            Console.WriteLine("{0={1", key, value);
        
        else
        {
            Console.WriteLine(@"Unable to retrieve value for '{0'", key);
        
    
    catch (ArgumentNullException)
    {
        Console.WriteLine("Unable to retrieve value for null key.");
    


The sample displays the following results:

Provider=sqloledb
DATA SOURCE=192.168.168.1,1433
Unable to retrieve value for //InvalidKey//
Unable to retrieve value for null key.

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

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