PropertyCollection 类

定义

表示可以添加到 DataColumnDataSetDataTable 的属性集合。Represents a collection of properties that can be added to DataColumn, DataSet, or DataTable.

public ref class PropertyCollection : System::Collections::Hashtable
[System.Serializable]
public class PropertyCollection : System.Collections.Hashtable
type PropertyCollection = class
    inherit Hashtable
Public Class PropertyCollection
Inherits Hashtable
继承
PropertyCollection
属性

示例

下面的示例创建一个 DataTable 的时间戳值,并将其添加到 PropertyCollection中。The following example creates a timestamp value for a DataTable and adds it to the PropertyCollection.

private void AddTimeStamp()
{
    //Create a new DataTable.
    DataTable table = new DataTable("NewTable");

    //Get its PropertyCollection.
    PropertyCollection properties = table.ExtendedProperties;

    //Add a timestamp value to the PropertyCollection.
    properties.Add("TimeStamp", DateTime.Now);

    // Print the timestamp.
    Console.WriteLine(properties["TimeStamp"]);
}
Private Sub AddTimeStamp()
    'Create a new DataTable.
    Dim table As New DataTable("NewTable")

    'Get its PropertyCollection.
    Dim properties As PropertyCollection = table.ExtendedProperties

    'Add a timestamp value to the PropertyCollection.
    properties.Add("TimeStamp", DateTime.Now)

    'Print the timestamp.
    Console.WriteLine(properties("TimeStamp"))
End Sub 

注解

可以通过 DataColumnDataSetDataTable 类的 ExtendedProperties 属性访问 PropertyCollectionThe PropertyCollection can be accessed through the ExtendedProperties property of the DataColumn, DataSet, or DataTable class.

通过 PropertyCollection将自定义属性添加到 DataColumnDataSetDataTable 对象。Add custom properties to the DataColumn, DataSet, or DataTable objects through the PropertyCollection. 例如,你可能想要存储对象的创建时间,以便以后与另一个对象进行比较。For example, you may want to store the time of the object's creation for later comparison to another object.

构造函数

PropertyCollection()

初始化 PropertyCollection 类的新实例。Initializes a new instance of the PropertyCollection class.

PropertyCollection(SerializationInfo, StreamingContext)

初始化 PropertyCollection 类的新实例。Initializes a new instance of the PropertyCollection class.

属性

comparer

获取或设置要用于 IComparerHashtableGets or sets the IComparer to use for the Hashtable.

(继承自 Hashtable)
Count

获取包含在 Hashtable 中的键/值对的数目。Gets the number of key/value pairs contained in the Hashtable.

(继承自 Hashtable)
EqualityComparer

获取要用于 IEqualityComparerHashtableGets the IEqualityComparer to use for the Hashtable.

(继承自 Hashtable)
hcp

获取或设置可分配哈希代码的对象。Gets or sets the object that can dispense hash codes.

(继承自 Hashtable)
IsFixedSize

获取一个值,该值指示 Hashtable 是否具有固定大小。Gets a value indicating whether the Hashtable has a fixed size.

(继承自 Hashtable)
IsReadOnly

获取一个值,用于指示 Hashtable 是否为只读。Gets a value indicating whether the Hashtable is read-only.

(继承自 Hashtable)
IsSynchronized

获取一个值,该值指示是否同步对 Hashtable 的访问(线程安全)。Gets a value indicating whether access to the Hashtable is synchronized (thread safe).

(继承自 Hashtable)
Item[Object]

获取或设置与指定的键关联的值。Gets or sets the value associated with the specified key.

(继承自 Hashtable)
Keys

获取包含 ICollection 中的键的 HashtableGets an ICollection containing the keys in the Hashtable.

(继承自 Hashtable)
SyncRoot

获取可用于同步对 Hashtable 的访问的对象。Gets an object that can be used to synchronize access to the Hashtable.

(继承自 Hashtable)
Values

获取一个 ICollection,它包含 Hashtable 中的值。Gets an ICollection containing the values in the Hashtable.

(继承自 Hashtable)

方法

Add(Object, Object)

将带有指定键和值的元素添加到 Hashtable 中。Adds an element with the specified key and value into the Hashtable.

(继承自 Hashtable)
Clear()

Hashtable 中移除所有元素。Removes all elements from the Hashtable.

(继承自 Hashtable)
Clone()

创建 PropertyCollection 对象的浅表副本。Creates a shallow copy of the PropertyCollection object.

Contains(Object)

确定 Hashtable 是否包含特定键。Determines whether the Hashtable contains a specific key.

(继承自 Hashtable)
ContainsKey(Object)

确定 Hashtable 是否包含特定键。Determines whether the Hashtable contains a specific key.

(继承自 Hashtable)
ContainsValue(Object)

确定 Hashtable 是否包含特定值。Determines whether the Hashtable contains a specific value.

(继承自 Hashtable)
CopyTo(Array, Int32)

Hashtable 元素复制到一维 Array 实例中的指定索引位置。Copies the Hashtable elements to a one-dimensional Array instance at the specified index.

(继承自 Hashtable)
Equals(Object)

确定指定的对象是否等于当前对象。Determines whether the specified object is equal to the current object.

(继承自 Object)
GetEnumerator()

返回循环访问 IDictionaryEnumeratorHashtableReturns an IDictionaryEnumerator that iterates through the Hashtable.

(继承自 Hashtable)
GetHash(Object)

返回指定键的哈希代码。Returns the hash code for the specified key.

(继承自 Hashtable)
GetHashCode()

用作默认哈希函数。Serves as the default hash function.

(继承自 Object)
GetObjectData(SerializationInfo, StreamingContext)

实现 ISerializable 接口,并返回序列化 Hashtable 所需的数据。Implements the ISerializable interface and returns the data needed to serialize the Hashtable.

(继承自 Hashtable)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
KeyEquals(Object, Object)

将特定 ObjectHashtable 中的特定键进行比较。Compares a specific Object with a specific key in the Hashtable.

(继承自 Hashtable)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
OnDeserialization(Object)

实现 ISerializable 接口,并在完成反序列化之后引发反序列化事件。Implements the ISerializable interface and raises the deserialization event when the deserialization is complete.

(继承自 Hashtable)
Remove(Object)

Hashtable 中移除包含指定键的元素。Removes the element with the specified key from the Hashtable.

(继承自 Hashtable)
ToString()

返回一个表示当前对象的 string。Returns a string that represents the current object.

(继承自 Object)

显式接口实现

IEnumerable.GetEnumerator()

返回循环访问集合的枚举器。Returns an enumerator that iterates through a collection.

(继承自 Hashtable)

扩展方法

Cast<TResult>(IEnumerable)

IEnumerable 的元素强制转换为指定的类型。Casts the elements of an IEnumerable to the specified type.

OfType<TResult>(IEnumerable)

根据指定类型筛选 IEnumerable 的元素。Filters the elements of an IEnumerable based on a specified type.

AsParallel(IEnumerable)

启用查询的并行化。Enables parallelization of a query.

AsQueryable(IEnumerable)

IEnumerable 转换为 IQueryableConverts an IEnumerable to an IQueryable.

适用于

另请参阅