Asp.net-mvc – How to submit a dropdownlist in asp.net mvc from an Ajax form

ajax.beginformasp.net-mvcdrop-down-menu

How do you submit from a dropdownlist "onchange" event from inside of an ajax form?

According to the following question: How do you submit a dropdownlist in asp.net mvc, from inside of an Html.BeginFrom you can set onchange="this.form.submit" and changing the dropdown posts back.

However, using the following code (inside an Ajax.BeginFrom):

<% using (Ajax.BeginForm("UpdateForm", new AjaxOptions() { UpdateTargetId = "updateText" })) { %>
    <h2>Top Authors</h2>

    Sort by:&nbsp;<%=Html.DropDownList("sortByList", new SelectList(ViewData["SortOptions"], new { onchange = "this.form.submit()" })%>

    <%= Html.TextBox("updateText")%>
<% } %>

Posts back to the controller action, but the entire page is replaced with the contents of the "updateText" text, rather than just what is inside the "updateText" textbox.

Thus, rather than replacing just the area inside the Ajax.BeginForm, the entire page is replaced.

What is the correct way for the dropdownlist to call this.form.submit such that only the area inside the Ajax.BeginForm?

Best Answer

OK, nearly 2 years later, you probably don't care anymore. Who knows: Maybe others (such as me ;-) do.

So here's the (extremely simple) solution:

In your Html.DropDownList(...) call, change

new { onchange = "this.form.submit()" }

new { onchange = "this.form.onsubmit()" }

Can you spot the difference? ;-)

The reason is that Ajax.BeginForm() creates a form with an onsubmit() handler to submit the form asynchronously. By calling submit(), you bypass this onsubmit() custom handler. Calling onsubmit() worked for me.

Related Solutions

Asp.net-mvc – Compile Views in ASP.NET MVC

From the readme word doc for RC1 (not indexed by google)

ASP.NET Compiler Post-Build Step

Currently, errors within a view file are not detected until run time. To let you detect these errors at compile time, ASP.NET MVC projects now include an MvcBuildViews property, which is disabled by default. To enable this property, open the project file and set the MvcBuildViews property to true, as shown in the following example:

<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <MvcBuildViews>true</MvcBuildViews>
  </PropertyGroup>

Note Enabling this feature adds some overhead to the build time.

You can update projects that were created with previous releases of MVC to include build-time validation of views by performing the following steps:

Open the project file in a text editor.
Add the following element under the top-most <PropertyGroup> element: <MvcBuildViews>true</MvcBuildViews>
At the end of the project file, uncomment the <Target Name="AfterBuild"> element and modify it to match the following:

<Target Name="AfterBuild" Condition="'$(MvcBuildViews)'=='true'">
    <AspNetCompiler VirtualPath="temp" PhysicalPath="$(ProjectDir)\..\$(ProjectName)" />
</Target>

C# – How to create a dropdownlist from an enum in ASP.NET MVC

For MVC v5.1 use Html.EnumDropDownListFor

@Html.EnumDropDownListFor(
    x => x.YourEnumField,
    "Select My Type", 
    new { @class = "form-control" })

For MVC v5 use EnumHelper

@Html.DropDownList("MyType", 
   EnumHelper.GetSelectList(typeof(MyType)) , 
   "Select My Type", 
   new { @class = "form-control" })

For MVC 5 and lower

I rolled Rune's answer into an extension method:

namespace MyApp.Common
{
    public static class MyExtensions{
        public static SelectList ToSelectList<TEnum>(this TEnum enumObj)
            where TEnum : struct, IComparable, IFormattable, IConvertible
        {
            var values = from TEnum e in Enum.GetValues(typeof(TEnum))
                select new { Id = e, Name = e.ToString() };
            return new SelectList(values, "Id", "Name", enumObj);
        }
    }
}

This allows you to write:

ViewData["taskStatus"] = task.Status.ToSelectList();

by using MyApp.Common