ASP. NET MVC Dropdownlist

This article describes how to display DropDownList in a Web page.

Step 1: Add a method inside the control

         Public actionresult showdropdownlist ()        {            return  View ();        }

Step 2: Add code to the View section

@Html. DropDownList ("Department",NewList<selectlistitem> {     NewSelectListItem {Text ="IT", Value ="1", Selected =true},    NewSelectListItem {Text ="HR", Value ="2"},    NewSelectListItem {Text ="Payroll", Value ="3"},}, "Select Department")

The above section is an option to add DropDownList as a "manual", and if you want to read the content through the database, first add the context and then get the contents of the datasheet through the context.

 public   ActionResult Showdropdownlist () { Sampledatacontext db  = new   Sampledataco            ntext (); Viewbag.departments  = new  selectlist (db. Departments,   ", "  name   );         return   View (); }

@Html. DropDownList ("departments""select Department")

The data saved in the viewbag.departments is automatically displayed in the DropDownList.

If you want an item to be displayed when it is loaded, you can

New " DepartmentID " " Name ");

Change to:

New " DepartmentID " " Name ","1");

Here "1" refers to the ID of the display item.

But this approach is still more "stupid", we can set a property in the table called isselected (as shown in the table), the value of each option to determine which item is selected.

 PublicActionResult showdropdownlist () {Sampledatacontext db=NewSampledatacontext (); List<SelectListItem> Selectlistitems =NewList<selectlistitem>(); foreach(varDepartmentinchdb. Departments) {SelectListItem SelectListItem=NewSelectListItem {Text=Department. Name, Value=Department. Departmentid.tostring (), Selected= Department. Isselected.hasvalue? Department. Isselected.value:false        };    Selectlistitems.add (SelectListItem); } viewbag.departments=Selectlistitems; returnView ();}

The view side remains the same.

ASP. NET MVC Dropdownlist