Enumerable.Repeat<TResult>(TResult, Int32) 方法
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。
生成包含一个重复值的序列。
public:
generic <typename TResult>
static System::Collections::Generic::IEnumerable<TResult> ^ Repeat(TResult element, int count);
C#
public static System.Collections.Generic.IEnumerable<TResult> Repeat<TResult> (TResult element, int count);
static member Repeat : 'Result * int -> seq<'Result>
Public Function Repeat(Of TResult) (element As TResult, count As Integer) As IEnumerable(Of TResult)
- TResult
要在结果序列中重复的值的类型。
- element
- TResult
要重复的值。
- count
- Int32
在生成序列中重复该值的次数。
IEnumerable<TResult>
一个包含重复值的 IEnumerable<T>。
count
小于 0。
下面的代码示例演示如何使用 Repeat 生成重复值的序列。
C#
IEnumerable<string> strings =
Enumerable.Repeat("I like programming.", 15);
foreach (String str in strings)
{
Console.WriteLine(str);
}
/*
This code produces the following output:
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
I like programming.
*/
' Repeat the same string to create a sequence.
Dim sentences As IEnumerable(Of String) =
Enumerable.Repeat("I like programming.", 15)
Dim output As New System.Text.StringBuilder
For Each sentence As String In sentences
output.AppendLine(sentence)
Next
' Display the output.
Console.WriteLine(output.ToString())
' This code produces the following output:
'
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
' I like programming.
此方法通过使用延迟执行来实现。 即时返回值是一个对象,用于存储执行操作所需的所有信息。 在通过直接调用GetEnumerator
其方法或通过在 C# For Each
或 foreach
Visual Basic 中使用 来枚举对象之前,不会执行此方法表示的查询。
产品 | 版本 |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |