转摘：Aspnet mvc Html.Checkbox 处理
2011-01-18 17:34
369 查看
This post will explain how to get the value of a checkbox when a form is
posted within the world of ASP.NET MVC. This post will explain this approach by
first presenting a common problem and then showing you
the recommended solution.
You can just jump to the solution by clicking here.
The Common Problem
A lot of times, you will ask a user to “sign up” or “register” to access your
web application. Sometimes, this process will involve asking a user to agree to
the terms of the site. This task usually relies on the user checking a checkbox
stating that they agree to be a nice user. For instance, you can see an example
of one such registration page here.
After a user has agreed, and decided to proceed, you should make sure they
checked the checkbox on the server side. The reason for this is to prevent
malicious developers from attacking your site. Regardless, if you are using
ASP.NET MVC, you may be surprised to learn that getting the value of a checkbox
is a little different from what you may be expecting. For instance, imagine you
have the following HTML page defined:
<html
xmlns=”http://www.w3.org/1999/xhtml” >
<head><title>Check
Test</title></head>
<body><form action=”/”
method=”post”>
<%= Html.CheckBox(”chkHuman”, false)%> Are you
human?<br />
<input type=”submit” value=”Move Along”
/>
</form></body>
</html>
Now imagine that when the user clicks the “Move Along” button, the following
action is triggered:
[AcceptVerbs(HttpVerbs.Post)]
public
ActionResult Index(FormCollection formValues)
{
string value =
formValues["chkHuman"];
return View();
}
If the user checks the checkbox, and this action gets executed, you will
notice the “value” variable will be set to “true,false”. If the checkbox was
not selected, the “value” variable will simply be “false”. While you
could just check the length, or manually parse the value, there is a more
elegant solution.
The Solution
The recommended approach would be to write your code as follows:
[AcceptVerbs(HttpVerbs.Post)]
public
ActionResult Index(FormCollection formValues)
{
bool isChecked =
false;
if (Boolean.TryParse(Request.Form.GetValues(”chkHuman”)[0], out
isChecked) == false)
ModelState.AddModelError(”chkHuman”, “Nice
try.”);
return RedirectToAction(”Index”);
}
In this approach, we are relying on the Request.Form object. By indexing the
first element of the value returned by the GetValues method, we will get either
“true” or “false”. This can then be easily converted to a bool. The fact that
the value can easily be converted to a bool is what makes it the recommended
approach.
原文
posted within the world of ASP.NET MVC. This post will explain this approach by
first presenting a common problem and then showing you
the recommended solution.
You can just jump to the solution by clicking here.
The Common Problem
A lot of times, you will ask a user to “sign up” or “register” to access your
web application. Sometimes, this process will involve asking a user to agree to
the terms of the site. This task usually relies on the user checking a checkbox
stating that they agree to be a nice user. For instance, you can see an example
of one such registration page here.
After a user has agreed, and decided to proceed, you should make sure they
checked the checkbox on the server side. The reason for this is to prevent
malicious developers from attacking your site. Regardless, if you are using
ASP.NET MVC, you may be surprised to learn that getting the value of a checkbox
is a little different from what you may be expecting. For instance, imagine you
have the following HTML page defined:
<html
xmlns=”http://www.w3.org/1999/xhtml” >
<head><title>Check
Test</title></head>
<body><form action=”/”
method=”post”>
<%= Html.CheckBox(”chkHuman”, false)%> Are you
human?<br />
<input type=”submit” value=”Move Along”
/>
</form></body>
</html>
Now imagine that when the user clicks the “Move Along” button, the following
action is triggered:
[AcceptVerbs(HttpVerbs.Post)]
public
ActionResult Index(FormCollection formValues)
{
string value =
formValues["chkHuman"];
return View();
}
If the user checks the checkbox, and this action gets executed, you will
notice the “value” variable will be set to “true,false”. If the checkbox was
not selected, the “value” variable will simply be “false”. While you
could just check the length, or manually parse the value, there is a more
elegant solution.
The Solution
The recommended approach would be to write your code as follows:
[AcceptVerbs(HttpVerbs.Post)]
public
ActionResult Index(FormCollection formValues)
{
bool isChecked =
false;
if (Boolean.TryParse(Request.Form.GetValues(”chkHuman”)[0], out
isChecked) == false)
ModelState.AddModelError(”chkHuman”, “Nice
try.”);
return RedirectToAction(”Index”);
}
In this approach, we are relying on the Request.Form object. By indexing the
first element of the value returned by the GetValues method, we will get either
“true” or “false”. This can then be easily converted to a bool. The fact that
the value can easily be converted to a bool is what makes it the recommended
approach.
原文
内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理 
相关文章推荐
- 拦截asp.net mvc输出流做处理, 拦截HTML文本（asp.net MVC版)
- asp.net MVC中使用Html.Checkbox提示该字符串未被识别为有效的布尔值错误的解决方法
- [转载]asp.net mvc: why is Html.CheckBox generating an additional hidden input
- 获取asp.net mvc中Html.CheckBox生成代码的值
- asp.net mvc中构建htmlHelper的checkboxlist
- Asp.net Mvc中使用普通的html超链接的处理
- ASP.Net MVC开发基础学习笔记：二、HtmlHelper与扩展方法
- ASP.NET MVC Html.TextBox 报 Object reference not set to an instance of an object 的解决方案
- ASP.NET MVC应用中一个诡异错误的处理
- asp.net mvc 处理”从客户端中检测到有潜在危险的 request.form 值。”
- 【翻译】了解ASP.NET MVC的HTML助手
- asp.net -mvc-Html.DropDownList
- C# ASP.NET MVC HtmlHelper用法大全
- [转自Scott]ASP.NET MVC框架(第四部分): 处理表单编辑和提交场景
- Asp.net MVC中Html.Partial, RenderPartial, Action,RenderAction 区别和用法（mvc部分视图的添加）
- 在asp.net mvc中使用PartialView返回部分HTML段
- ASP.NET MVC编程——错误处理与日记
- ASP.NET MVC实践系列8-对查询后分页处理的解决方案
- C# ASP.NET MVC HtmlHelper
- ASP.NET MVC Razor 输出没有编码的HTML字符串