删除页面中Form下面隐藏的ViewStatue

protected override void Render(HtmlTextWriter writer) 
{ 
System.IO.StringWriter html = new System.IO.StringWriter(); 
System.Web.UI.HtmlTextWriter tw = new System.Web.UI.HtmlTextWriter(html); 
base.Render(tw); 
string Temp = html.ToString(); 
string s1 = string.Empty, s2 = string.Empty, s3 = string.Empty, s4 = string.Empty, s5 = string.Empty, s6 = string.Empty; 
int i = 0; 
int j = 0; 
i = Temp.IndexOf("<form"); 
if (i > 0) 
{ 
j = Temp.IndexOf(">", i); 
s1 = Temp.Substring(0, i); 
s2 = Temp.Substring(j + 1, Temp.Length - j - 1); 
} 
i = s2.IndexOf("<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE""); 
if (i > 0) 
{ 
j = s2.IndexOf(">", i); 
s3 = s2.Substring(0, i); 
s4 = s2.Substring(j + 1, s2.Length - j - 1); 
} 
i = s4.IndexOf("<input type="hidden" name="__EVENTVALIDATION" id="__EVENTVALIDATION""); 
if (i > 0) 
{ 
j = s4.IndexOf(">", i); 
s5 = s4.Substring(0, i); 
s6 = s4.Substring(j + 1, s4.Length - j - 1); 
Temp = s1 + s3 + s5 + s6; 
} 
else 
{ 
Temp = s1 + s3 + s4; 
} 
Temp = Temp.Replace("</form>", ""); 
Temp = Temp.Replace("
", ""); 
tw.Close(); 
Response.Write(Temp); 
}