what is string builder ? with exaple program in a c# code

Question

Satyapriya Nayak · Answer

Normal 0 Hi Fire StringBuilder is more efficient in the cases where a lot of manipulation is done to the text. Strings are immutable so each time it's being operated on a new instance is created. Ex:- Delete multiple values from the gridview Untitled Page function ConfirmOnDelete(item) { if (confirm(Would you like to delete selected item(s)?)==true) return true; else return false; } onrowdatabound=GridView1_RowDataBound > Text=Label> using System; using System.Collections; using System.Configuration; using System.Data; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; using System.Data.SqlClient; using System.Collections.Specialized; using System.Collections.Generic; using System.Text; public partial class _Default : System.Web.UI.Page { string connStr = ConfigurationManager.ConnectionStrings[ConnectionString].ConnectionString; SqlCommand cmd = new SqlCommand(); SqlConnection con; string str; protected void Page_Load(object sender EventArgs e) { if (!Page.IsPostBack) BindGridView(); totalrecords(); } private void totalrecords() { con = new SqlConnection(connStr); //cmd.Connection = con; con.Open(); str = select count(*) from employee ; SqlCommand cmd = new SqlCommand(str con); int row = (int)cmd.ExecuteScalar(); Label2.Text = row.ToString(); con.Close(); } private void BindGridView() { con = new SqlConnection(connStr); cmd.Connection = con; cmd.CommandText = Select * from employee; con.Open(); GridView1.DataSource = cmd.ExecuteReader(); GridView1.DataBind(); con.Close(); } private void DeleteRecords(StringCollection sc) { con = new SqlConnection(connStr); StringBuilder sb = new StringBuilder(string.Empty); foreach (string item in sc) { const string sqlStatement = DELETE FROM employee WHERE EmpId; sb.AppendFormat({0}='{1}';  sqlStatement item); } try { con.Open(); SqlCommand cmd = new SqlCommand(sb.ToString() con); cmd.CommandType = CommandType.Text; cmd.ExecuteNonQuery(); } catch (System.Data.SqlClient.SqlException ex) { string msg = Deletion Error:; msg += ex.Message; throw new Exception(msg); } finally { con.Close(); } } protected void ButtonDelete_Click(object sender EventArgs e) { StringCollection sc = new StringCollection(); string id = string.Empty; for (int i = 0; i { CheckBox cb = (CheckBox)GridView1.Rows[i].Cells[0].FindControl(CheckBox1); if (cb != null) { if (cb.Checked) { id = GridView1.Rows[i].Cells[1].Text; sc.Add(id); } } } DeleteRecords(sc); BindGridView(); totalrecords(); } protected void GridView1_RowDataBound(object sender GridViewRowEventArgs e) { if (e.Row.RowType == DataControlRowType.Header) { Button b = (Button)e.Row.FindControl(ButtonDelete); b.Attributes.Add(onclick return ConfirmOnDelete();); } } } Thanks