DbConnectionStringBuilder.Keys 属性
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
获取包含 ICollection 中的键的 DbConnectionStringBuilder。
public:
virtual property System::Collections::ICollection ^ Keys { System::Collections::ICollection ^ get(); };public virtual System.Collections.ICollection Keys { get; }[System.ComponentModel.Browsable(false)]
public virtual System.Collections.ICollection Keys { get; }member this.Keys : System.Collections.ICollection[<System.ComponentModel.Browsable(false)>]
member this.Keys : System.Collections.ICollectionPublic Overridable ReadOnly Property Keys As ICollection属性值
一个 ICollection，它包含 DbConnectionStringBuilder 中的键。
实现
- 属性
示例
以下控制台应用程序示例创建新的 DbConnectionStringBuilder，并添加一些键。 代码遍历 ICollection 显示 Keys 键/值对的属性返回的 ，然后添加新键。 由于 属性 Keys 返回动态 ICollection，因此第二个循环显示所有键/值对，包括最新的项。
static void Main()
{
DbConnectionStringBuilder builder = new
DbConnectionStringBuilder();
builder["Data Source"] = "(local)";
builder["Integrated Security"] = true;
builder["Initial Catalog"] = "AdventureWorks";
// Obtain reference to the collection of keys.
ICollection keys = builder.Keys;
Console.WriteLine("Keys before adding TimeOut:");
foreach (string key in keys)
Console.WriteLine("{0}={1}", key, builder[key]);
// Add a new item to the collection.
builder["Timeout"] = 300;
Console.WriteLine();
Console.WriteLine("Keys after adding TimeOut:");
// Because the Keys property is dynamically updated,
// the following loop includes the Timeout key.
foreach (string key in keys)
Console.WriteLine("{0}={1}", key, builder[key]);
Console.WriteLine();
Console.WriteLine("Press Enter to continue.");
Console.ReadLine();
}
Sub Main()
Dim builder As New DbConnectionStringBuilder
builder("Data Source") = "(local)"
builder("integrated security") = True
builder("Initial Catalog") = "AdventureWorks;NewValue=Bad"
' Obtain reference to the collection of keys.
Dim keys As ICollection = builder.Keys
Console.WriteLine("Keys before adding TimeOut:")
For Each key As String In keys
Console.WriteLine("{0}={1}", key, builder(key))
Next
' Add a new item to the collection.
builder("Timeout") = 300
Console.WriteLine()
Console.WriteLine("Keys after adding TimeOut:")
' Because the Keys property is dynamically updated,
' the following loop includes the Timeout key.
For Each key As String In keys
Console.WriteLine("{0}={1}", key, builder(key))
Next
Console.WriteLine()
Console.WriteLine("Press Enter to continue.")
Console.ReadLine()
End Sub
注解
ICollection 中的值的顺序未指定，但与 ICollection 属性返回的 Values 中的关联值顺序相同。
返回的 ICollection 不是静态副本;相反， ICollection 引用回原始 DbConnectionStringBuilder中的键。 因此，对 DbConnectionStringBuilder 的更改将反映在 中 ICollection。
