绕好大一个圈。
直接继承，加一个可get、set的Encoding属性，然后override CurrentEncoding 属性，就可以了。
public class EncodableStringWriter : StringWriter
{
public EncodableStringWriter() : base(){}
public EncodableStringWriter(IFormatProvider formatProvider) : base(formatProvider){}
public EncodableStringWriter(StringBuilder sb) : base(sb){}
public EncodableStringWriter(StringBuilder sb, IFormatProvider formatProvider) : base(sb, formatProvider){}
private Encoding _encoding;
/// <summary>
///
/// </summary>
/// <param name="encoding">写入输出时所使用的System.Text.Encoding。</param>
public EncodableStringWriter(Encoding encoding) : base()
{
this._encoding = encoding;
}
/// <summary>
///
/// </summary>
/// <param name="formatProvider"></param>
/// <param name="encoding">写入输出时所使用的System.Text.Encoding。</param>
public EncodableStringWriter(IFormatProvider formatProvider, Encoding encoding) : base(formatProvider)
{
this._encoding = encoding;
}
/// <summary>
///
/// </summary>
/// <param name="sb"></param>
/// <param name="encoding">写入输出时所使用的System.Text.Encoding。</param>
public EncodableStringWriter(StringBuilder sb, Encoding encoding) : base(sb)
{
this._encoding = encoding;
}
/// <summary>
///
/// </summary>
/// <param name="sb"></param>
/// <param name="formatProvider"></param>
/// <param name="encoding">写入输出时所使用的System.Text.Encoding。</param>
public EncodableStringWriter(StringBuilder sb, IFormatProvider formatProvider, Encoding encoding) : base(sb, formatProvider)
{
this._encoding = encoding;
}
/// <summary>
/// 获取写入输出时所使用的System.Text.Encoding。
/// </summary>
public override Encoding Encoding
{
get
{
return this._encoding == null ? Encoding.Default : this._encoding;
}
}