ASP.NET interview questions: - How to make GridView Editable, Updateable and Deleteable in ASP.NET?

The process of making GridView Editable, Updateable and Deleteable is almost used in the entire ASP.NET project. So, making GridView Editable, Updateable and Deleteable is one of the most important aspects according to any ASP.NET project.

Let’s create a simple demonstration to understand the concept of making GridView Editable, Updateable and Deleteable in much better manner.

In order to see it practically you just need to follow the following steps.

Step1: - Create a simple ASP.NET Web Application for that just open Visual Studio >>go to >> File >> New >> Project >> Web >> Select ASP.NET Empty Web Application.

Step2: - Now, simply just add a Web Form to your ASP.NET
Empty Web Application for that just go to >> Solution Explorer >> Right Click on the project name >> Add >> New Item >> Select Web Form.

Now, simply just drag and drop GridView to your Web Form and allow the below
properties to true.

1. Allow AutoGenerateEditButton to True.

2. Allow AutoGenerateDeleteButton to True.

Now, as soon as you set the above two properties you will see the GridView like below diagram.

Step3: - Now, let bind the GridView with Data for that just add the below
code snippet in to your WebForm.aspx.cs file.

        //Below variable holds the Connection String.
string str = ConfigurationManager.AppSettings["Connect"];

protected void Page_Load(object sender, EventArgs e)
 {
  if (!IsPostBack)
  {
      GridViewData();
  }
}

//Created a GridViewData method to bind data to GridView
//from the SQL Server DataBase Table.
public void GridViewData()
{
  SqlConnection con = new SqlConnection(str);
  con.Open();
  SqlCommand com = new SqlCommand();
  com.CommandText = "select * from Book";
  com.Connection = con;
  com.ExecuteNonQuery();
  SqlDataAdapter adap = new SqlDataAdapter(com);
  DataSet ds = new DataSet();
  adap.Fill(ds);
  GridView1.DataSource = ds;
  GridView1.DataBind();
}

Step4: - This is the most important step while making GridView Editable, Updateable and Deleteable.

Now, simply just add the below Events of the GridView control in to your
Web Application.

1. OnRowEditing.

2. OnRowCancelingEdit.

3. OnRowUpdating.

4. OnRowDeleting.

Step5: - now, just add the below code snippet to make necessary changes on the respective events of the
GridView control.

1. OnRowEditing add the below code snippet.

 protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
 {
  GridView1.EditIndex = e.NewEditIndex;
  GridViewData();
  }

2. OnRowCanelingEdit add the below code snippet.

 protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
  GridView1.EditIndex = -1;
  GridViewData();
}

3. OnRowDeleting add the below code snippet.

 protected void GridView1_RowDeleting(object sender, GridViewDeleteEventArgs e)
  {
  //The below line of code will hold the Cells[1] data of th GridView Control.
  string id = GridView1.Rows[e.RowIndex].Cells[1].Text;
  SqlConnection con = new SqlConnection(str);
  con.Open();
  SqlCommand com = new SqlCommand();
  com.CommandText = "delete from Book where Book_Id = '"+id+"'";
  com.Connection = con;
  com.ExecuteNonQuery();
  GridViewData();
 }

4. OnRowUpdating add the below code snippet.

        protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
  string id = ((TextBox)GridView1.Rows[e.RowIndex].Cells[1].Controls[0]).Text;
  string bookname = ((TextBox)GridView1.Rows[e.RowIndex].Cells[2].Controls[0]).Text;            string author = ((TextBox)GridView1.Rows[e.RowIndex].Cells[3].Controls[0]).Text;
  string price = ((TextBox)GridView1.Rows[e.RowIndex].Cells[4].Controls[0]).Text;
  string quantity = ((TextBox)GridView1.Rows[e.RowIndex].Cells[5].Controls[0]).Text;
  SqlConnection con = new SqlConnection(str);
  con.Open();
  SqlCommand com = new SqlCommand();
  com.CommandText = "update Book set Book_Name='" + bookname + "',Book_Author='" + author + "',Book_Price='" + price + "',Book_Quantity='" + quantity + "' where Book_Id= '" + id + "'";
  com.Connection = con;
  com.ExecuteNonQuery();
  GridViewData();
}

Note: - You can modify your code according to your requirements.

Step6: - Now, let’s run your Web Application and see the respective results.

Let’s first see the result for deleting.

The above diagram is my output of the loaded GridView and note that I am going to delete the
circled row data from the GridView control.

Now, as soon as you click on the delete link will see the result like below diagram.

In the above result of diagram you can see that the data has been deleted.

Similarly, let’s see the result for updating the below circled row data in the
GridView control.

Now, as soon as you click on the edit link you will see something like below diagram.

Now, let’s modify the Book_Author Name as Kalim Shaikh and click on the Update link and see whether the data is updated or not.

In the above output diagram you can clearly see that now the Book_Author name is modified to
Kalim Shaikh.

See the following video on ASP.NET Tracing and instrumentation.



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