ASP.NET

bool LoadSubIndustries = true;
public int IndustryId { get; set; }

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

    LoadSubIndustries = false;
}

private void Populate_SubIndustry()
{
    DataSet dsSubIndustries = lookupManager.GetSubIndsutryByIndustryId(IndustryId);

    ddlSubIndustry.DataSource = dsSubIndustries.Tables["Lookup_SubIndustry"].DefaultView;
    ddlSubIndustry.DataValueField = "Id";
    ddlSubIndustry.DataTextField = "SubIndustry";

    ddlSubIndustry.DataBind();
}

private void Populate_Industry()
{
    DataSet dsIndustries = lookupManager.GetIndustries();

    ddlIndustry.DataSource = dsIndustries.Tables["Lookup_Industry"].DefaultView;
    ddlIndustry.DataValueField = "Id";
    ddlIndustry.DataTextField = "Industry";

    ddlIndustry.DataBind();
}

protected void ddlIndustry_SelectedIndexChanged(object sender, EventArgs e)
{
    if (LoadSubIndustries == false)
    {
        IndustryId = (int.Parse(ddlIndustry.SelectedValue.ToString()));
        Populate_SubIndustry();
    }
}

protected void ddlIndustry_SelectedIndexChanged(object sender, EventArgs e)
{
    if (LoadSubIndustries == false)
    {
        IndustryId = (int.Parse(ddlIndustry.SelectedValue.ToString()));
        Populate_SubIndustry();
    }
}

Mark Nischalke wrote:

First, read this[^]

Abhishek Sur wrote:

It will dispose cmd as it is ByRef.

Dim b As New SqlClient.SqlCommand()
x(b)
b.CommandText = "" ' this will allow Because of ByVal but will assign            ' value ddd to CommandText

Public Sub x(ByVal rr As SqlClient.SqlCommand)
        rr.CommandText = "dddd"
        rr.Dispose()
        rr = nothing
End Sub

 private void button1_Click(object sender, EventArgs e)
 {
      SqlCommand cmd = new SqlCommand();
      this.x(ref cmd);
      cmd.CommandText = ""; // This will throw Error... 
           
 }

private void x(ref SqlCommand com)
{
     com = null;
}

Abhishek Sur wrote:

I thought everything that is not derived from ValueTypes are called ByRef.
But it isnt actually.

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

       'prueba 1
       Dim b As New SqlClient.SqlCommand()
       Prueba1(b)
       ''here  the variable     b have       commandtext="ddddddd",    commandtimeout=45,
       ''CommandType = CommandType.StoredProcedure
       b.CommandText = ""


       'prueba 2
   End Sub
   Public Sub Prueba1(ByVal rr As SqlClient.SqlCommand)
       rr.CommandText = "dddd"
       rr.CommandTimeout = 45
       rr.CommandType = CommandType.StoredProcedure

       rr.Dispose()
       rr = Nothing
   End Sub

public class PersonDataService
           public void Person_Save(ref int personID, string nameFirst, string nameLast, DateTime dob)
        {
            SqlCommand cmd;
            ExecuteNonQuery(out cmd, "Person_Save",
                CreateParameter("@PersonID", SqlDbType.Int, personID, ParameterDirection.InputOutput),
                CreateParameter("@NameFirst", SqlDbType.NVarChar, nameFirst),
                CreateParameter("@NameLast", SqlDbType.NVarChar, nameLast),
                CreateParameter("@DOB", SqlDbType.DateTime, dob));            
            personID = (int)cmd.Parameters["@PersonID"].Value;
            cmd.Dispose();
        }

        protected void ExecuteNonQuery(string procName,
            params IDataParameter[] procParams)
        {
            SqlCommand cmd;
            ExecuteNonQuery(out cmd, procName, procParams);
        }
protected void ExecuteNonQuery(out SqlCommand cmd, string procName,
            params IDataParameter[] procParams)
        {
            //Method variables
            SqlConnection cnx = null;
            cmd = null;  //Avoids "Use of unassigned variable" compiler error

            try
            {
                //Setup command object
                cmd = new SqlCommand(procName);
                cmd.CommandType = CommandType.StoredProcedure;
                for (int index = 0; index < procParams.Length; index++)
                {
                    cmd.Parameters.Add(procParams[index]);
                }

                //Determine the transaction owner and process accordingly
                if (_isOwner)
                {
                    cnx = new SqlConnection(GetConnectionString());
                    cmd.Connection = cnx;
                    cnx.Open();
                }
                else
                {
                    cmd.Connection = _txn.Connection;
                    cmd.Transaction = _txn;
                }

                //Execute the command
                cmd.ExecuteNonQuery();
            }
            catch
            {
                throw;
            }
            finally
            {
                if (_isOwner)
                {
                    cnx.Dispose(); //Implicitly calls cnx.Close()
                }
                if (cmd != null) cmd.Dispose();
            }
        }