StringDictionary.Remove(String) 方法
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。
从字符串字典中删除具有指定键的条目。
public:
virtual void Remove(System::String ^ key);
public virtual void Remove(string key);
abstract member Remove : string -> unit
override this.Remove : string -> unit
Public Overridable Sub Remove (key As String)
参数
- key
- String
要删除的项的键。
例外
键为 null.
示例
下面的代码示例演示如何在 StringDictionary. 中添加和删除元素。
using System;
using System.Collections;
using System.Collections.Specialized;
public class SamplesStringDictionary {
public static void Main() {
// Creates and initializes a new StringDictionary.
StringDictionary myCol = new StringDictionary();
myCol.Add( "red", "rojo" );
myCol.Add( "green", "verde" );
myCol.Add( "blue", "azul" );
// Displays the values in the StringDictionary.
Console.WriteLine( "Initial contents of the StringDictionary:" );
PrintKeysAndValues( myCol );
// Deletes an element.
myCol.Remove( "green" );
Console.WriteLine( "The collection contains the following elements after removing \"green\":" );
PrintKeysAndValues( myCol );
// Clears the entire collection.
myCol.Clear();
Console.WriteLine( "The collection contains the following elements after it is cleared:" );
PrintKeysAndValues( myCol );
}
public static void PrintKeysAndValues( StringDictionary myCol ) {
Console.WriteLine( " KEY VALUE" );
foreach ( DictionaryEntry de in myCol )
Console.WriteLine( " {0,-10} {1}", de.Key, de.Value );
Console.WriteLine();
}
}
/*
This code produces the following output.
Initial contents of the StringDictionary:
KEY VALUE
green verde
red rojo
blue azul
The collection contains the following elements after removing "green":
KEY VALUE
red rojo
blue azul
The collection contains the following elements after it is cleared:
KEY VALUE
*/
Imports System.Collections
Imports System.Collections.Specialized
Public Class SamplesStringDictionary
Public Shared Sub Main()
' Creates and initializes a new StringDictionary.
Dim myCol As New StringDictionary()
myCol.Add("red", "rojo")
myCol.Add("green", "verde")
myCol.Add("blue", "azul")
' Displays the values in the StringDictionary.
Console.WriteLine("Initial contents of the StringDictionary:")
PrintKeysAndValues(myCol)
' Deletes an element.
myCol.Remove("green")
Console.WriteLine("The collection contains the following elements after removing ""green"":")
PrintKeysAndValues(myCol)
' Clears the entire collection.
myCol.Clear()
Console.WriteLine("The collection contains the following elements after it is cleared:")
PrintKeysAndValues(myCol)
End Sub
Public Shared Sub PrintKeysAndValues(myCol As StringDictionary)
Dim de As DictionaryEntry
Console.WriteLine(" KEY VALUE")
For Each de In myCol
Console.WriteLine(" {0,-10} {1}", de.Key, de.Value)
Next de
Console.WriteLine()
End Sub
End Class
'This code produces the following output.
'
'Initial contents of the StringDictionary:
' KEY VALUE
' green verde
' red rojo
' blue azul
'
'The collection contains the following elements after removing "green":
' KEY VALUE
' red rojo
' blue azul
'
'The collection contains the following elements after it is cleared:
' KEY VALUE
'
注解
StringDictionary如果不包含具有指定键的元素,则StringDictionary保持不变。 不会引发异常。
密钥以不区分大小写的方式进行处理;在用于查找要从字符串字典中删除的条目之前,它将转换为小写。
此方法是 O(1) 操作。