internal MvcCaptchaImage(MvcCaptchaOptions options)
{
CaptchaOptions = options;
UniqueId = Guid.NewGuid().ToString("N");
_rand = new Random();
//Text = GenerateRandomText();
}
static string CreateImgTag(string url, MvcCaptchaOptions options, string id)
{
var sb = new StringBuilder("<a href=\"javascript:;\" title=\"刷新图片\"><img src=\"");
sb.Append(url);
sb.Append("\" alt=\"刷新图片\" width=\"");
sb.Append(options.Width);
sb.Append("\" height=\"");
sb.Append(options.Height);
if (!string.IsNullOrEmpty(id))
sb.Append("\" id=\"").Append(id);
sb.Append("\" border=\"0\"/></a><!--<a href=\"javascript:_reloadMvcCaptchaImage()\">").Append(options.ReloadLinkText).Append("</a>-->");
return sb.ToString();
}
protected void Page_Load(object sender, EventArgs e)
{
HttpContext context = HttpContext.Current;
MvcCaptchaOptions options = new MvcCaptchaOptions();
var image = new MvcCaptchaImage(options);
image.ResetText();
HttpContext.Current.Session.Add("captcha", image.Text);
using (var b = image.RenderImage())
{
b.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Gif);
}
context.Response.Cache.SetNoStore();
context.Response.Cache.SetCacheability(System.Web.HttpCacheability.NoCache);
context.Response.ContentType = "image/gif";
context.Response.StatusCode = 200;
context.Response.StatusDescription = "OK";
context.ApplicationInstance.CompleteRequest();
}
private static MvcHtmlString MvcCaptcha(this HtmlHelper helper, string actionName, string controllerName, MvcCaptchaOptions options)
{
if (options == null)
options = new MvcCaptchaOptions();
var image = new MvcCaptchaImage(options);
HttpContext.Current.Session.Add(
image.UniqueId,
image);
var url = new UrlHelper(helper.ViewContext.RequestContext);
var sb = new StringBuilder(1500);
sb.Append("<input type=\"hidden\" name=\"" + options.CaptchaImageContainerGUId + "\" id=\"" + options.CaptchaImageContainerGUId + "\"");
if (options.DelayLoad)
{
sb.Append("/><script language=\"javascript\" type=\"text/javascript\">if (typeof (jQuery) == \"undefined\") { alert(\"jQuery脚本库未加载，请检查！\"); }");
sb.Append("var _mvcCaptchaPrevGuid = null,_mvcCaptchaImgLoaded = false;function _loadMvcCaptchaImage(){");
sb.Append("if(!_mvcCaptchaImgLoaded){$.ajax({type:'GET',url:'");
sb.Append(url.Action("MvcCaptchaLoader", "_MvcCaptcha", new RouteValueDictionary { { "area", null } }));
sb.Append("?'+_mvcCaptchaPrevGuid,global:false,success:function(data){_mvcCaptchaImgLoaded=true;");
sb.Append("$(\"#" + options.CaptchaImageContainerGUId + "\").val(data);_mvcCaptchaPrevGuid=data;$(\"#");
sb.Append(options.CaptchaImageContainerId).Append("\").html('");
sb.Append(CreateImgTag(url.Action(actionName, controllerName, new RouteValueDictionary { { "area", null } }) + "?'+data+'", options, null));
sb.Append("');}});} };function _reloadMvcCaptchaImage(){_mvcCaptchaImgLoaded=false;_loadMvcCaptchaImage();};$(function(){");
sb.Append("if($(\"#").Append(options.ValidationInputBoxId).Append("\").length==0){alert(\"未能找到验证码输入文本框，请检查ValidationInputBoxId属性是否设置正确！\");}");
sb.Append("if($(\"#").Append(options.CaptchaImageContainerId).Append("\").length==0){alert(\"未能找到验证码图片父容器，请检查CaptchaImageContainerId属性是否设置正确！\");}");
sb.Append("$(\"#").Append(options.ValidationInputBoxId);
sb.Append("\").bind(\"focus\",_loadMvcCaptchaImage)});</script>");
}
else
{
sb.AppendFormat(" value=\"{0}\" />", image.UniqueId);
sb.Append(CreateImgTag(url.Action(actionName, controllerName, new RouteValueDictionary { { "area", null } }) + "?" + image.UniqueId, options, image.UniqueId));
sb.Append("<script language=\"javascript\" type=\"text/javascript\">$(\"#" + image.UniqueId + "\").live(\"click\",function(){");
//sb.Append(image.UniqueId);
sb.Append("var slen=$(this).attr(\"src\").length;var cobj=$(this).attr(\"src\").indexOf(\"&\");var osrc=$(this).attr(\"src\").substr(0,slen)+\"&" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + "\";$(this).attr(\"src\",osrc);return false;});</script>");
}
return MvcHtmlString.Create(sb.ToString());
}
public ActionResult MvcCaptchaLoader()
{
string prevGuid = Request.ServerVariables["Query_String"];
if (!string.IsNullOrEmpty(prevGuid))
HttpContext.Session.Remove(prevGuid);
var options = new MvcCaptchaOptions();
var config = MvcCaptchaConfigSection.GetConfig();
if (config != null)
{
options.TextChars = config.TextChars;
options.TextLength = config.TextLength;
options.FontWarp = config.FontWarp;
options.BackgroundNoise = config.BackgroundNoise;
options.LineNoise = config.LineNoise;
}
var image = new MvcCaptchaImage(options);
HttpContext.Session.Add(
image.UniqueId,
image);
HttpContext.Response.Cache.SetNoStore();
HttpContext.Response.Cache.SetCacheability(HttpCacheability.NoCache);
return Content(image.UniqueId);
}
public static MvcHtmlString MvcCaptcha(this HtmlHelper helper, MvcCaptchaOptions options)
{
return MvcCaptcha(helper, "MvcCaptchaImage", "_MvcCaptcha", options);
}
