How to bind Gridview using strong model binding in asp.net

In our previous article, we have already learn how to bind GridView using ado.net, Entityframework, etc. Now, today we will learn strong model binding. Follow my steps
Step-1 :  Create a course.cs class, which is include in my previous article
Step-2 : Create a another class, which named as DataContext.cs class also include in my previous article.
Step-3 : After adding the two class in the project , add a new web form, which named as "getItem.aspx".
Step-4 : Add GridView control on web form
Step-5 :  Your source code looking like this

<form id="form1" runat="server">
    <div>
    
    </div>
        <asp:GridView ID="GridView1" runat="server" DataKeyNames ="ID" AutoGenerateColumns="false" ItemType="course" SelectMethod="getCourse">
            <Columns>
                
                <asp:BoundField DataField="ID" HeaderText="Course_Id" />
                  <asp:BoundField DataField="ccode" HeaderText="Course_code" />
                 <asp:BoundField DataField="cname" HeaderText="Course_Name" />


            </Columns>
        </asp:GridView>
    </form>

Here we add two extra attribute, which names as SelectMethod and ItemType. ItemType define the whole structure of your code. Suppose your course class inside in a namespace then your ItemType is
namespace.class name. Using the select method you can retrieve table data from database.

Step-6 : copy this code and paste into your code behind page

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class getitem : System.Web.UI.Page
{
    private readonly DataContext dc = new DataContext();
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    public IQueryable<course> getCourse()
    {
        return dc.courses;
    }

}
First to create DataContext object, which is used for retrieving data from database. Also create Select method which return  IQueryable type.

Code generate the following output

How to Bind Gridview using Entity Framework in ASP.NET

In our previous article, we have already learned that how to bind gridview using ado.net. Today we will learn simplest technique to bind gridview using entity framework. Lets start to bind.

Step-1 : Add a Course class with some attributes like

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

/// <summary>

/// Summary description for course

/// </summary>

public class course

{

    public int ID { get; set; }

    public string cname { get; set; }

    public string ccode { get; set; }

}

In this code ID is the primary key of the table. Learn How to make primary key in entity framework.

Step-2 : Add a DataContext class for creating database with some table like.

using System;

using System.Collections.Generic;

using System.Data.Entity;

using System.Linq;

using System.Web;

/// <summary>

/// Summary description for DataContext

/// </summary>

public class DataContext : DbContext

{

public DataContext():base ("connection1")

{

//

// TODO: Add constructor logic here

//

}

  

    public DbSet<course> courses { get; set; }

}

DataContext class inherit from DbContext class which is inside in System.Data.Entity namespace. Learn How to download it. 

Here we pass ConnectionString in base class constructor as a parameter. Also add Course table in DataContext using DbSet. 

Step-3 : Add a new webform, which named as "getItem.aspx". Also add a gridView control onit from toolBox.

Step-4 : Add this code in codebehind page.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

public partial class getitem : System.Web.UI.Page

{

    DataContext dc = new DataContext();

    protected void Page_Load(object sender, EventArgs e)

    {

        if (!Page.IsPostBack)

        {

            bindgrid();

        }

    }

    private void bindgrid()

    {

        var item = from d in dc.courses

                   select d;

        GridView1.DataSource = item.ToList();

        GridView1.DataBind();

        

    }

}

Code Generate the following output

How to download EntityFramework.dll file, Add System.Data.Entity namespace

This namespace take some classes of entity framework for accessing data. In this article we will learn how to add System.Data.Entity namespace because Entity framework.dll missing by default. So first to add entityframework.dll file as a reference.
How to download
Step-1 : Select Package Manager console from Tool menu.

Step-2 : Write
PM> Install-package entityframework

Note : Internet connection must.
Now, Using this method you can download latest version of entityframework.

How to populate comboBox in windows form c#

ComboBox is a collection, in which we can take Text as well as value of the text. After array, developer designed comboBox or DropDownList because array contains one attribute of object, its does not take two value at a time. Suppose you want to store employee name and age into memory. Where we would not use array. Here we will bind the comboBox in different manner like
Method-1 : Bind ComboBox from dataset and datatable using ADO.NET
Method-2 : Bind ComboBox using Entity framework.

Method-1

I have a database table like Students, which take some value. The Data View of table, which is stored in database.

C# Code for binding ComboBox (Binding from DataReader)

using System;
using WindowsFormsApplication10;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.Entity;
using System.Data.SqlClient;

namespace WindowsFormsApplication10
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
           
            SqlConnection con = new SqlConnection();
            con.ConnectionString = "Data Source=(LocalDB)\\v11.0; Initial Catalog=STUDENTer; Integrated Security=true";
            con.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.CommandText = "select * from Students";
            cmd.Connection = con;
            SqlDataReader rd = cmd.ExecuteReader();
            while (rd.Read ())
            {
                string name = rd.GetString(1);
                comboBox1.Items.Add(name);

            }

        }
    }
}

Binding from DataTable

 private void Form1_Load(object sender, EventArgs e)
        {
           
            SqlConnection con = new SqlConnection();
            con.ConnectionString = "Data Source=(LocalDB)\\v11.0; Initial Catalog=STUDENTer; Integrated Security=true";
            con.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.CommandText = "select * from Students";
            cmd.Connection = con;
            SqlDataReader rd = cmd.ExecuteReader();
            DataTable dt = new DataTable();
            dt.Load(rd);
            comboBox1.DataSource = dt;
            comboBox1.DisplayMember = "name";

        }

Binding from DataSet

 private void Form1_Load(object sender, EventArgs e)
        {
           
            SqlConnection con = new SqlConnection();
            con.ConnectionString = "Data Source=(LocalDB)\\v11.0; Initial Catalog=STUDENTer; Integrated Security=true";
            con.Open();
            SqlCommand cmd = new SqlCommand();
            cmd.CommandText = "select * from Students";
            cmd.Connection = con;
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            da.Fill(ds);
            comboBox1.DataSource = ds.Tables[0];
            comboBox1.DisplayMember = "name";

        }

Method-2

If you want to bind combobox using entity framework or you can say strong model binding, just follow my steps.
Step-1 : One class, which name as "Student.cs", which works as database table.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace WindowsFormsApplication10
{
   public class Student
    {
        public int Id { get; set; }
        public string name { get; set; }
    }
}
In this class we are taking two member first is Id and second is name.
Step-2 : Take another class, which name as "DataContext", which is used for creating database also used for inserting table in it. Look like

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Text;

namespace WindowsFormsApplication10
{
    class DataContext: DbContext
    {
        public DataContext() :
            base("connectionstring1")
        {
           

        }
        public DbSet<Student> Students { get; set; }

    }
}

In this code, DataContext class inherited from DbContext class. Base class constructor create database using conectionstring, which is defined in App.Config file. like

<connectionStrings>

    <add name="connectionstring1" providerName="System.Data.SqlClient" connectionString="Data Source=(LocalDB)\v11.0; Initial Catalog=STUDENTer; Integrated Security=true" />

  </connectionStrings>

Step-3 : Add ComboBox control on form
Step-4 : Copy this code and paste into your form load event
private void Form1_Load(object sender, EventArgs e)
        {
            DataContext dc=new DataContext();
            var stu = from student in dc.Students
                      select new
                      {
                         student.name
                      };
            comboBox1.DataSource = stu.ToList();
            comboBox1.DisplayMember = "name";

        }

Code Generate the following output

How to use font dialog in winforms c#

Font dialog is used for changing the font style of the text. In font style there are many attributes available like font face, font color, font size etc. Now, if you want to use font dialog in windows form then simple drag a font dialog control from the tool box and drop into your form page also set some required properties , OK lets take an simple example, in this we take some control on windows form and change their font attribute through font dialog. follow my steps for using font dialog control.



Step-1 : Add one rich textBox and Button control on the form.
Step-2 : Raise click event on button control.
Step-3 : Copy this code and paste into your button control event handler.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication11
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            FontDialog ftdlg = new FontDialog();
            ftdlg.ShowColor = true;
            if (ftdlg.ShowDialog ()==DialogResult.OK & !String.IsNullOrEmpty(richTextBox1.Text))
            {
                richTextBox1.SelectionFont = ftdlg.Font;
                richTextBox1.SelectionColor = ftdlg.Color;
            }
        }
    }
}

Now code generate the following output

In this example, first line in event handler define, first to create instance of font dialog, font dialog control doesn't show color in it bydefault so you can change property of it using set ShowColor is true, which is define in second line. In third line we are checking that font dialog is open also return true, when we press OK button. 

Note : Third line also check that 'text' must be selected in rich textBox

 After setting the attribute you can assign attribute to selected text, which is define in fifth and sixth line in the code

Return Text Input Element using Html.TextBox() handler: MVC

Html.TextBox() handler used to return text input element on the page at run time. It supports some types of parameters discussed and also have some more options to returning text inputs on the page. Mostly it is of two types listed below with their specification and uses.

@Html.TextBox(Parameter collection...)

This html handler is used to return text input element to be input some values by user like name, age, address and more. As this element is used like a method in Asp.Net MVC, this may have some parameters to be passed with it. This handler returns only an input field in the form of

<input type="text" name="name" id="id" />

Following is list of parameters this handler may used:

• Name: used to specify name of form field (can be used to find control on page) and this parameter is of string type.
• Value: this parameter is of type object and used to specify value of text input element. If this value is null then this element will get the value from viewdata dictionary otherwise model data dictionary.
• Format: used to format the input value in prescribed format string. To format the text input in date form, programmer may use "{0:d}"
• Html Attributes: the object contains html attributes to set for the element like class, font size and many more attributes.
  @Html.TextBox("txtName", "Student Name", "{0:d}", new { @class = "txtClass" })

@Html.TextBoxFor(Parameter collection...)

The main difference between @Html.TextBox() and @Html.TextBoxFor() is this handler use prediction to resolve the value to be shown. All the remaining parameters are same in both the handlers.

This method is used when programmer binds this page through a model class (having some properties). Programmer can specify more html attributes within the related section.

For example the following line of code will fix the max length of textbox
@Html.TextBoxFor(m=>m.Name, new { maxlength = "20" })

To disabled the textbox just specify the disabled attribute like written below:
@Html.TextBoxFor(m=>m.Name, new { disabled = "disabled" })

Return Label Element using Html.Label() Handler: MVC

Html.Label() handler used to return label element on the page at run time. It supports some types of parameters discussed and also have some more options to returning labels on the page. Mostly it is of three types listed below with their specification and uses.

Html.Label(parameter collection...)

This Html handler is used to return label element with property name specified by the parameter expression. Here is collection of parameter this html handler used:

• Expression: used to identify the property to display.
• label text: specify the text of label to display.
• Html Attributes: this parameter is type of object, contains all the elements to be set for this label element.
  @Html.Label("stName", "Student Name", new { @class = "lblClass" })

Html.LabelFor(parameter collection...)

This handler is used for showing the label element of property passed from the model, the page bind. For example the page is bind to student model and we bind this handler with student name then this handler will show the name of student like shown below:

@Html.LabelFor(model => model.Name)
Here model represent the class name passed to bind this view. This parameter must be defined in prediction type as shown in the above code, without prediction it will show an error. Remaining parameters are same as Html.Label() handler.

@Html.LabelForModel(parameter collection...)

This handler returns a label whose for value is that of the parameter represented by the model object. It is mostly used in editor templates in MVC View. e.g.

@Html.LabelForModel() - it shows the label element for the string property of model bind with this view.