SqlConnectionStringBuilder.ContainsKey(String) 方法

public:
 override bool ContainsKey(System::String ^ keyword);

public override bool ContainsKey(string keyword);

override this.ContainsKey : string -> bool

Public Overrides Function ContainsKey (keyword As String) As Boolean

参数

返回

如果 SqlConnectionStringBuilder 包含具有指定键的元素，则为 true；否则为 false。

例外

示例

以下示例创建一个 SqlConnectionStringBuilder 实例，设置其某些属性，然后尝试通过调用 ContainsKey 方法来确定对象中是否存在各种键。

using Microsoft.Data.SqlClient;

class Program
{
    static void Main()
    {
        SqlConnectionStringBuilder builder =
            new SqlConnectionStringBuilder(GetConnectionString());
        Console.WriteLine("Connection string = " + builder.ConnectionString);

        // Keys you have provided return true.
        Console.WriteLine(builder.ContainsKey("Server"));

        // Comparison is case insensitive, and synonyms
        // are automatically converted to their "well-known"
        // names.
        Console.WriteLine(builder.ContainsKey("Database"));

        // Keys that are valid but have not been set return true.
        Console.WriteLine(builder.ContainsKey("Max Pool Size"));

        // Keys that do not exist return false.
        Console.WriteLine(builder.ContainsKey("MyKey"));

        Console.WriteLine("Press Enter to continue.");
        Console.ReadLine();

    }

    private static string GetConnectionString()
    {
        // To avoid storing the connection string in your code,
        // you can retrieve it from a configuration file. 
        return "Server=(local);Integrated Security=SSPI;" +
            "Initial Catalog=AdventureWorks";
    }
}

该示例在控制台窗口中显示以下输出：

Connection string = Data Source=(local);Initial Catalog=AdventureWorks;Integrated Security=True  
True  
True  
True  
False  

注解

由于 SqlConnectionStringBuilder 包含固定大小的键/值对集合，因此 ContainsKey 方法只确定特定键名是否有效。