StreamWriter.Null 字段

定义

提供 StreamWriter,它不带任何可写入但无法从中读取的后备存储。Provides a StreamWriter with no backing store that can be written to, but not read from.

public: static initonly System::IO::StreamWriter ^ Null;
public static readonly System.IO.StreamWriter Null;
 staticval mutable Null : System.IO.StreamWriter
Public Shared ReadOnly Null As StreamWriter 

字段值

StreamWriter

示例

下面的示例演示如何使用 Null 字段。The following example demonstrates a use of the Null field.

if ( sw->Equals( StreamWriter::Null ) )
{
   sw->WriteLine( "The store can be written to, but not read from." );
}
if(sw.Equals(StreamWriter.Null))
{
    sw.WriteLine("The store can be written to, but not read from.");
}
If Sw.Equals(StreamWriter.Null) Then
    Sw.WriteLine("The store can be written to, but not read from.")
End If

注解

使用将 Null 输出重定向到 StreamWriter 不会消耗任何操作系统资源的。Use Null to redirect output to a StreamWriter that will not consume any operating system resources.

StreamWriter.Write 在上调用方法时 Null ,调用只会返回,而不会向任何后备存储写入任何数据。When the StreamWriter.Write methods are invoked on Null, the call simply returns, and no data is actually written to any backing store.

有关常见 i/o 任务的列表,请参阅 常见 I/o 任务For a list of common I/O tasks, see Common I/O Tasks.

适用于