Dynamically Creating DataTable and Binding To GridView Without Database

For dynamically creating DataTable and binding to GridView without database, we have to know the following things:

1. How to create columns in a DataTable.
2. How to add rows in a DataTable.
   

Syntax For Creating Column in DataTable

DataTable mytable=new DataTable();
mytable.columns.add("ColunmName",TypeOf(string/int/Float));

Syntax For Creating Rows 

DataTable mytable=new DataTable(); //creating datatable
DataRow dr=mytable.NewRow(); //Creating Row
dr["ColunmName"]="Raj"; //assigning value to the row
mytable.Rows.add(dr); //adding to datatable

Example

Step 1: Design the form as in the following image:



Step 2: When the form is filled and enter button is hit, we want that the value should not be added in the database, but instead of this it should be directly added to my DataTable so that I could bind the DataTable and show directly in the
form.

Step 3: For this add a GridView in the form and name it as GridView1.

Step 4: Now under show button click, write the following code:

protected void btn_1_Click(object sender, EventArgs e)
{
   GridView1.Visible = true; //my grid view name
   createnewrow(); //call a function
}

Step 5: Create the function createnewrow().

public void createnewrow()
{
    DataTable mytable = new DataTable();
    if (ViewState["Row"] != null)
    {
        mytable = (DataTable) ViewState["Row"];
        DataRow dr = null;
        if (mytable.Rows.Count > 0)
        {
            dr = mytable.NewRow();
            dr["Id"] = txt_id.Text;
            dr["Name"] = txt_name.Text;
            dr["Location"] = txt_location.Text;
            dr["Salary"] = txt_salary.Text;
            mytable.Rows.Add(dr);
            ViewState["Row"] = mytable;
            GridView1.DataSource = ViewState["Row"];
            GridView1.DataBind();
        }
    }
    else
    {
        mytable.Columns.Add("Id", typeof(int));
        mytable.Columns.Add(new DataColumn("Name", typeof(string)));
        mytable.Columns.Add("Location", typeof(string));
        mytable.Columns.Add("Salary", typeof(float));
        DataRow dr1 = mytable.NewRow();
        dr1 = mytable.NewRow();
        dr1["Id"] = txt_id.Text;
        dr1["Name"] = txt_name.Text;
        dr1["Location"] = txt_location.Text;
        dr1["Salary"] = txt_salary.Text;
        mytable.Rows.Add(dr1);
        ViewState["Row"] = mytable;
        GridView1.DataSource = ViewState["Row"];
        GridView1.DataBind();
    }
}

Now after show button click, it will directly show the record.



Explanation:

 

1. For the first time the condition for the Viewstate is false, so the control goes to else part and creates the columns for the datatable.
   
   
2. Create rows and add the Textbox value to them.
   
   
3. Saving the table in viewstate.
   
   
4. Binding the viewstate to the Gridview.
   
   
5. After first time, the vewstate condition becomes true and it directly creates only rows and is added to the table.