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StringWriter 类

更新:2007 年 11 月

实现一个用于将信息写入字符串的 TextWriter。该信息存储在基础 StringBuilder 中。

命名空间:  System.IO
程序集:  mscorlib(在 mscorlib.dll 中)

[SerializableAttribute]
[ComVisibleAttribute(true)]
public class StringWriter : TextWriter
/** @attribute SerializableAttribute */ 
/** @attribute ComVisibleAttribute(true) */
public class StringWriter extends TextWriter
public class StringWriter extends TextWriter

下表列出了其他典型或相关的 I/O 任务的示例。

若要执行此操作...

请参见本主题中的示例...

创建文本文件。

如何:向文件写入文本

写入文本文件。

如何:向文件写入文本

读取文本文件。

如何:从文件读取文本

向文件中追加文本。

如何:打开并追加到日志文件

File.AppendText

FileInfo.AppendText

获取文件大小。

FileInfo.Length

获取文件属性。

File.GetAttributes

设置文件属性。

File.SetAttributes

确定文件是否存在。

File.Exists

读取二进制文件。

如何:对新建的数据文件进行读取和写入

写入二进制文件。

如何:对新建的数据文件进行读取和写入

下面的代码示例阐释了如何用一组双倍间距的句子创建一个连续的段落,然后将该段落重新转换为原来的文本。

using System;
using System.IO;

class StringRW
{
    static void Main()
    {
        string textReaderText = "TextReader is the abstract base " +
            "class of StreamReader and StringReader, which read " +
            "characters from streams and strings, respectively.\n\n" +

            "Create an instance of TextReader to open a text file " +
            "for reading a specified range of characters, or to " +
            "create a reader based on an existing stream.\n\n" +

            "You can also use an instance of TextReader to read " +
            "text from a custom backing store using the same " +
            "APIs you would use for a string or a stream.\n\n";

        Console.WriteLine("Original text:\n\n{0}", textReaderText);

        // From textReaderText, create a continuous paragraph 
        // with two spaces between each sentence.
        string aLine, aParagraph = null;
        StringReader strReader = new StringReader(textReaderText);
        while(true)
        {
            aLine = strReader.ReadLine();
            if(aLine != null)
            {
                aParagraph = aParagraph + aLine + " ";
            }
            else
            {
                aParagraph = aParagraph + "\n";
                break;
            }
        }
        Console.WriteLine("Modified text:\n\n{0}", aParagraph);

        // Re-create textReaderText from aParagraph.
        int intCharacter;
        char convertedCharacter;
        StringWriter strWriter = new StringWriter();
        strReader = new StringReader(aParagraph);
        while(true)
        {
            intCharacter = strReader.Read();

            // Check for the end of the string 
            // before converting to a character.
            if(intCharacter == -1) break;

            convertedCharacter = Convert.ToChar(intCharacter);
            if(convertedCharacter == '.')
            {
                strWriter.Write(".\n\n");

                // Bypass the spaces between sentences.
                strReader.Read();
                strReader.Read();
            }
            else
            {
                strWriter.Write(convertedCharacter);
            }
        }
        Console.WriteLine("\nOriginal text:\n\n{0}", 
            strWriter.ToString());
    }
}


import System.*;
import System.IO.*;

class StringRW
{
    public static void main(String[] args)
    {
        String textReaderText = "TextReader is the abstract base " 
            + "class of StreamReader and StringReader, which read " 
            + "characters from streams and strings, respectively.\n\n" 
            + "Create an instance of TextReader to open a text file " 
            + "for reading a specified range of characters, or to " 
            + "create a reader based on an existing stream.\n\n" 
            + "You can also use an instance of TextReader to read " 
            + "text from a custom backing store using the same " 
            + "APIs you would use for a string or a stream.\n\n";

        Console.WriteLine("Original text:\n\n{0}", textReaderText);

        // From textReaderText, create a continuous paragraph 
        // with two spaces between each sentence.
        String aParagraph = "";
        String aLine;
        StringReader strReader = new StringReader(textReaderText);
        while (true) {
            aLine = strReader.ReadLine();
            if (aLine != null) {
                aParagraph = aParagraph + aLine + " ";
            }
            else {
                aParagraph = aParagraph + "\n";
                break ;
            }
        }
        Console.WriteLine("Modified text:\n\n{0}", aParagraph);

        // Re-create textReaderText from aParagraph.
        int intCharacter;
        char convertedCharacter;
        StringWriter strWriter = new StringWriter();
        strReader = new StringReader(aParagraph);

        while (true) {
            intCharacter = strReader.Read();

            // Check for the end of the string 
            // before converting to a character.
            if (intCharacter == -1) {
                break ;
            }

            convertedCharacter = Convert.ToChar(intCharacter);
            if (convertedCharacter == '.') {
                strWriter.Write(".\n\n");

                // Bypass the spaces between sentences.
                strReader.Read();
                strReader.Read();
            }

            else {
                strWriter.Write(convertedCharacter);
            }
        }
        Console.WriteLine("\nOriginal text:\n\n{0}", strWriter.ToString());
    } //main
} //StringRW


此类型的任何公共 static(在 Visual Basic 中为 Shared) 成员都是线程安全的。但不保证所有实例成员都是线程安全的。

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360

.NET Framework 和 .NET Compact Framework 并不是对每个平台的所有版本都提供支持。有关支持的版本的列表,请参见.NET Framework 系统要求

.NET Framework

受以下版本支持:3.5、3.0、2.0、1.1、1.0

.NET Compact Framework

受以下版本支持:3.5、2.0、1.0

XNA Framework

受以下版本支持:2.0、1.0
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