asp.net-mvc MVC Html.CheckBox 和表单提交问题
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MVC Html.CheckBox and form submit issue
提问by Andriy Tkach
Crazy issue with submitting of values in Html.Checkbox in ASP.NET MVC RC
在 ASP.NET MVC RC 中提交 Html.Checkbox 中的值的疯狂问题
Some of the values are just not come to Request.Params
一些值只是没有来到 Request.Params
At my form I have this line inside the cycle: <%=Html.CheckBox("cb" + p.Option.Id, p.Option.IsAllowed, new { value = 6 })%>
在我的表单中，我在循环中有这一行： <%=Html.CheckBox("cb" + p.Option.Id, p.Option.IsAllowed, new { value = 6 })%>
and it renders to next:
它呈现到下一个：
<input checked="checked" id="cb17" name="cb17" type="checkbox" value="6" />
<input name="cb17" type="hidden" value="false" />
<input checked="checked" id="cb18" name="cb18" type="checkbox" value="6" />
<input name="cb18" type="hidden" value="false" />
<input id="cb19" name="cb19" type="checkbox" value="6" />
<input name="cb19" type="hidden" value="false" />
<input id="cb20" name="cb20" type="checkbox" value="6" />
<input name="cb20" type="hidden" value="false" />
<input checked="checked" id="cb21" name="cb21" type="checkbox" value="6" />
<input name="cb21" type="hidden" value="false" />
After submitting the Form I'm get something like:
提交表格后，我得到如下信息：
Form.Params["cb17"] = {6, "false"}
Form.Params["cb18"] = {6, "false"}
Form.Params["cb19"] = {"false"}
Form.Params["cb20"] = {"6,false"}
Form.Params["cb21"] = {"false"}
In the request string Some of the params are displayed twice (normal situation) and some only ONE TIME (only value of hidden field). It seems that it doesn't rely on whether checkbox was checked or not, whether value has changed or so...
在请求字符串中，有些参数显示两次（正常情况），有些只显示一次（仅隐藏字段的值）。似乎它不依赖于是否选中了复选框，值是否已更改等等......
Does anybody faced with such a situation? How can I work around?
有人遇到过这种情况吗？我该如何解决？
回答by TStamper
<% using(Html.BeginForm("Retrieve", "Home")) %>//Retrieve is the name of the action while Home is the name of the controller
<% { %>
<%foreach (var app in newApps) { %>
<tr>
<td><%=Html.CheckBox(""+app.ApplicationId )%></td>
</tr>
<%} %>
<input type"submit"/>
<% } %>
and in your controller
并在您的控制器中
List<app>=newApps; //Database bind
for(int i=0; i<app.Count;i++)
{
var checkbox=Request.Form[""+app[i].ApplicationId];
if(checkbox!="false")// if not false then true,false is returned
}
the reason you check for false because the Html Checkbox helper does some kind of freaky thing for value true
您检查 false 的原因是因为 Html Checkbox 助手为 true 值做了某种奇怪的事情
True returns as:
True 返回为：
it makes the string read "true, false"
so you may have thought it was two values but its just one and means true
所以你可能认为它是两个值，但它只是一个并且意味着真的
False returns as:
假返回为：
it makes the string read "false"
回答by veggerby
This is actually the way it should work according to specifications.
这实际上是它应该根据规范工作的方式。
It has nothing to do with ASP.NET MVC, but when a check box is left unchecked it is notincluded in the POST collection.
它与 ASP.NET MVC 无关，但是当复选框未选中时，它不会包含在 POST 集合中。
You get two values because you have both a checkbox and an input with the same name (and the ones you have two values for are most likely the ones with checkboxes checked).
你得到两个值，因为你有一个复选框和一个同名的输入（你有两个值的那些很可能是选中了复选框的那些）。
Edit: specificationsfrom W3C
编辑：规格从W3C
回答by Andriy Tkach
Without the need to ask database about the ids after form submitting/before saving (Stateless mode) I've produced such code:
无需在表单提交后/保存前（无状态模式）向数据库询问 id，我已经生成了这样的代码：
foreach (string key in Request.Form)
{
var checkbox = String.Empty;
if (key.StartsWith("cb"))
{
checkbox = Request.Form["" + key];
if (checkbox != "false")
{
int id = Convert.ToInt32(key.Remove(0, 2));
}
}
}
Thanks you guys to help me work around this issue!
谢谢你们帮我解决这个问题！
回答by Lord of Scripts
I use this:
我用这个：
public struct EditedCheckboxValue
{
public bool Current { get; private set; }
public bool Previous { get; private set; }
public bool Changed { get; private set; }
public EditedCheckboxValue(System.Web.Mvc.FormCollection collection, string checkboxID) : this()
{
string[] values = collection[checkboxID].Split(new char[] { ',' });
if (values.Length == 2)
{ // checkbox value changed, Format: current,old
Current = bool.Parse(values[0]);
Previous = bool.Parse(values[1]);
Changed = (Current != Previous);
}
else if (values.Length == 1)
{
Current = bool.Parse(values[0]);
Previous = Current;
Changed = false;
}
else
throw new FormatException("invalid format for edited checkbox value in FormCollection");
}
}
and then call it like this:
然后像这样调用它：
EditedCheckboxValue issomething = new EditedCheckboxValue(collection, "FieldName");
instance.IsSomething = issomething.Current;
