使用Dropdownlist Visual Basic调用MVC actionResult

问题描述

我希望下拉列表在onChange事件之后触发对ActionResult的调用，而不是将整个表单提交给服务器。想法是，必须先将所选项目发送到服务器，以检查所选公司在数据库中是否可用，然后才能继续填写其他详细信息。同样，当用户键入他们的姓名时，onChange还将触发一个事件以检查该用户是否在数据库中可用。

index.vbhtml

@Using Html.BeginForm("Authorise","Login",FormMethod.Post)
<div>
    @Html.DropDownListFor(Function(x) x.SelectedItems,Model.CompanyID,New With {Key .id = "CompanyID"})
</div>
<div>
   @Html.TextBoxFor(Function(model) model.UserName,New With {Key .id = "UserName"})
</div>
<div>
   @Html.TextBoxFor(Function(model) model.UserPassword,New With {Key .id = "UserPassword"})
</div>
End Using

LoginController：

Function onChangeCompanyName() As ActionResult
      .... code to check availability of selected value...
    return View()
End Function

Function onChangeUsername() As ActionResult
      .... code to check availability of selected value...
    return View()
End Function

LoginModel.cs

Public Class LoginModel
    Public Property CompanyID As String
    Public Property LoginErrorMessage As String
    Public Property Username() As String
    Public Property UserPassword() As String
    Public Property SelectedItems As IEnumerable(Of String)
    Public Property Items As IEnumerable(Of SelectListItem)
End Class

任何解决方案或与可能解决方案的链接将不胜感激。

解决方法

如果您没有安全问题，可以使用此 解决方案，按照您的要求进行操作，步骤如下：

• 在index.vbhtml中使用JQuery 从您的客户下拉列表中获取价值 然后使用AJAX通过POST发送数据

<script>
  function checkMyId(id) {
    $.ajax({
      type: "POST",url: "/Home/AjaxMethodeCheck",data: '{id: "' + id + '" }',contentType: "application/json; charset=utf-8",dataType: "json",success: function (response) {
        alert(response.message);
        var value = response.value;
        // do the job ...
      },failure: function (response) {
        alert("failure");
      },error: function (response) {
        alert("error");
      },});
  }
  $(document).ready(function () {
    $(function () {
      $("#YourDropDownId").change(function () {
        var selected = $(this).find("option:selected");
        checkMyId(selected.val());
      });
    });
  });
</script>

• 在您的控制器中，您将收到数据并进行检查
• 然后将结果以json格式发送回JQuery：

    <HttpPost>
    Public Function AjaxMethodeCheck(ByVal id As String) As JsonResult

        Dim Str As String = "Done !"  ' if you want to send back message ...
        Dim value As Integer = 0      ' if you want to send back data ...

        ' Do your job in vb.net

        Dim response = New With {
        .id = id,.message = Str,.value = value}

        Return Json(response)
    End Function

• 使用该结果的jQuery（ajax成功：）