public string StringByReplacingCharactersInRange(NSRange range,
string str0) {
int length = this.Length();
string stringBegin = this.content.Substring(0,(range.start)-(0));
string stringEnd = this.content.Substring(range.end + 1,(length)-(range.end + 1));
return stringBegin + str0 + stringEnd;
}
public string SubstringWithRange(NSRange range) {
return this.content.Substring(range.start,(range.end)-(range.start));
}