使用这个类转换一下即可 public sealed class CleanString{
public static string InputText( string inputString,
                                int maxLength
                               ){
System.Text.StringBuilder retVal
    = new System.Text.StringBuilder();
// check incoming parameters for null or blank string
if( ( inputString != null ) && ( inputString != String.Empty ) ){
inputString = inputString.Trim();//eliminate spacer
//chop the string incase the client-side max length
//fields are bypassed to prevent buffer over-runs
if ( inputString.Length > maxLength ){
inputString = inputString.Substring( 0,
                                     maxLength
                                    );
                }
//convert some harmful symbols incase the regular
//expression validators are changed
for( int i = 0; i< inputString.Length; i++ ){
switch( inputString[i] ){
case '"':
retVal.Append( "&quot;" );
break;
case '<':
retVal.Append( "&lt;" );
break;
case '>':
retVal.Append( "&gt;" );
break;
default:
retVal.Append( inputString[i] );
break;
}
}
// Replace single quotes with white space
retVal.Replace( "'",
                " "
               );
}
return retVal.ToString();
}
}