FormCollection in ASP.NET MVC

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FormCollection in ASP.NET MVC Application

In this article, I am going to discuss FormCollection in ASP.NET MVC Application. Please read our previous article where we discussed Business Objects as Models in the ASP.NET MVC Application. We are also going to work with the same example that we worked on in our previous article. Here, in this article, we will create a view to insert a new employee into the database table Employee using the FormCollection class that is available in ASP.NET MVC Framework.

Creating a view to inserting data using FormCollection in MVC

We want to create a view as shown below to create a new employee.

Creating the Create Action Method:

Please Copy and paste the following “Create” action method in the EmployeeController class. Please note the following action method is decorated with the HttpGet attribute. This makes the Create Action Method to respond only to the “GET” request.

[HttpGet]
public ActionResult Create()
{
    return View();
}

Adding the Create View:

Now let’s add the “Create” view. To do this right-click on the “Create” action method and select “Add View” from the context menu. Set

View name = “Create”
Template = “Create”
Model class = Employee (BusinessLayer)

Click on the “Add” button as shown below.

At this point “Create.cshtml” view will be added to the “Employee” folder. Run the application and navigate to the  URL “http://localhost:54094/Employee/Index“. Click on the “Create New” link. It will navigate to the URL http://localhost:54094/Employee/Create URL and will display the following page.

A form with text boxes to add a new employee is rendered. For employee “Gender“, it is ideal to have a dropdown list instead of a text box. To achieve this replace the following line of code.

After the changes, the complete code for the create view as shown below

@model BusinessLayer.Employee
@{
    ViewBag.Title = "Create";
}
<h2>Create Employee</h2>
@using (Html.BeginForm()) 
{
    @Html.AntiForgeryToken()
    
    <div class="form-horizontal">
        
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            @Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Name, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Gender, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownList("Gender", new List<SelectListItem>
                {
                new SelectListItem { Text = "Male", Value="Male" },
                new SelectListItem { Text = "Female", Value="Female" }
                }, "Select Gender", new { @class = "form-control" })


                @Html.ValidationMessageFor(model => model.Gender, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.City, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.City, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.City, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Salary, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.Salary, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Salary, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.DateOfBirth, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.DateOfBirth, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.DateOfBirth, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
}

<div>
    @Html.ActionLink("Back to List", "Index")
</div>

<script src="~/Scripts/jquery-1.10.2.min.js"></script>
<script src="~/Scripts/jquery.validate.min.js"></script>
<script src="~/Scripts/jquery.validate.unobtrusive.min.js"></script>

Now, run the application and notice that a dropdown list is rendered for “Gender”. Now, if you click on the “Create” button you will get an error message stating – The resource cannot be found. This is because we don’t have the “Create” action method that can handle HTTPPost requests.

What is the FormCollection Class in ASP.NET MVC?

The FormCollection class in ASP.NET MVC will automatically receive the posted form values in the controller action method in the form of key/value pairs. The values can be accessed using either key names or indexes. We can use the FormCollection to loop through each key and its value that is posted to the server. Let’s add the following Create Post method in the employee Controller class.

[HttpPost]
public ActionResult Create(FormCollection formCollection)
{
    if (ModelState.IsValid)
    {
        foreach (string key in formCollection.AllKeys)
        {
            Response.Write("Key = " + key + "  ");
            Response.Write("Value = " + formCollection[key]);
            Response.Write("<br/>");
        }
    }
    return View();
}

Now run the application and fill the view and click on the create button as shown below.

The output is as shown below.

Let’s create a stored procedure to insert the employee object in the Employee table

Create procedure spAddEmployee  
  @Name nvarchar(50),
  @Gender nvarchar (10),
  @City nvarchar (50),
  @Salary decimal(18,2),
  @DateOfBirth DateTime
As
Begin
  Insert into Employee(Name, Gender, City, Salary, DateOfBirth)
  Values (@Name, @Gender, @City,@Salary, @DateOfBirth)
End

Add the following method to the EmployeeBusinessLayer.cs file.

//Add employee into the database. This method takes an argument of Employee type which contains the 
//employee that is going to stored in the database
public void AddEmmployee(Employee employee)
{
    //Creating the connection string
    string connectionString = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
    //Establishing the connection to the database
    using (SqlConnection con = new SqlConnection(connectionString))
    {
        //Creating the command object by passing the stored procedure and connection object as argument
        //This stored procedure is used to store the employee in to the database
        SqlCommand cmd = new SqlCommand("spAddEmployee", con)
        {
            //Specifying the command as stored procedure
            CommandType = CommandType.StoredProcedure
        };

        //Creating SQL parameters because that stored procedure accept some input values
        SqlParameter paramName = new SqlParameter
        {
            //Storing the parameter name of the stored procedure into the SQL parameter
            //By using ParameterName property 
            ParameterName = "@Name",
            //storing the parameter value into sql parameter by using Value ptoperty
            Value = employee.Name
        };
        //Adding that parameter into Command objects Parameter collection by using Add method
        //which will take the SQL parameter name as argument
        cmd.Parameters.Add(paramName);

        //Same for all other parameters (Gender, City, DateOfBirth )
        SqlParameter paramGender = new SqlParameter
        {
            ParameterName = "@Gender",
            Value = employee.Gender
        };
        cmd.Parameters.Add(paramGender);

        SqlParameter paramCity = new SqlParameter
        {
            ParameterName = "@City",
            Value = employee.City
        };
        cmd.Parameters.Add(paramCity);

        SqlParameter paramSalary = new SqlParameter
        {
            ParameterName = "@Salary",
            Value = employee.Salary
        };
        cmd.Parameters.Add(paramSalary);

        SqlParameter paramDateOfBirth = new SqlParameter
        {
            ParameterName = "@DateOfBirth",
            Value = employee.DateOfBirth
        };
        cmd.Parameters.Add(paramDateOfBirth);

        //Open the connection and execute the command on ExecuteNonQuery method
        con.Open();
        cmd.ExecuteNonQuery();
    }
}

To save form data to a database table modify the create (HttpPost) action method EmployeeController.cs file as shown below.

//FormCollection will store the submitted form data automatically when the form is submitted
[HttpPost]
public ActionResult Create(FormCollection formCollection)
{
            Employee employee = new Employee();
            // Retrieve form data using form collection
            employee.Name = formCollection["Name"];
            employee.Gender = formCollection["Gender"];
            employee.City = formCollection["City"];
            employee.Salary =Convert.ToDecimal(formCollection["Salary"]);
            employee.DateOfBirth = Convert.ToDateTime(formCollection["DateOfBirth"]);

            EmployeeBusinessLayer employeeBusinessLayer = new EmployeeBusinessLayer();

            employeeBusinessLayer.AddEmmployee(employee);
            return RedirectToAction("Index");
}

Now Run the application and see everything is working as expected.

But the question is do we really have to write all the dirty codes of retrieving data from FormCollection class and assign it to the properties of the “employee” object. The answer is no. This is the job of the model binder in the ASP.NET MVC Application. In the next article, I am going to discuss the Model Binders in ASP.NET MVC application with Examples. Here, in this article, I try to explain how to use FormCollection in ASP.NET MVC application with an example. I hope you enjoy this FormCollection in ASP.NET MVC article.