Q4: Is that possible to not to fire validation when a button is clicked?

This is one of the most commonly asked questions on www.asp.net forums.

Q5: How can I redirect to another page after the exception has thrown?

Have you ever tried redirecting your page in the catch block. It won't work if you don't supply the correct parameters. Let's say you try something like this:

 

try { // Do some work here and suppose the exception is thrown } catch(Exception ex) { Response.Redirect("ErrorPage.aspx"); }

You should be expecting that you will be redirected to the "ErrorPage.aspx" page but unfortunately this will throw "System.Threading" exception. If you want to redirect to the "ErrorPage.aspx" than you will have to do something like this:

 

try { // Do some work here and suppose the exception is thrown } catch(Exception ex) { Response.Redirect("ErrorPage.aspx",true); }

As you can see that I have provided the second parameter to "true" for the Response.Redirect method which terminates the execution of the current page and redirects to the new page successfully.

Q6: How can I populate one dropdownlist based on the selected of another dropdownlist?

This is one of the most frequently asked questions. Suppose you have a dropdownlist and you want that when you select any item from that dropdownlist then another dropdownlist should be populated. I have created two dropdownlist "ddlParent" and "ddlChild". Let's see how this be done.

First let's populate the "ddlParent":

 

if(!Page.IsPostBack) { SqlDataAdapter ad = new SqlDataAdapter("SELECT PersonID FROM Person",myConnection); DataSet ds = new DataSet(); ad.Fill(ds,"Person"); ddlParent.DataSource = ds; ddlParent.DataTextField = "PersonID"; ddlParent.DataValueField = "PersonID"; ddlParent.DataBind(); }

As you can see that populated the dropdownlist was not that hard. Now in the selectedIndexChanged event of the "ddlParent" you will implement the code that will fill the "ddlChild". Let's see how this is accomplished:

 

private void ddlParent_SelectedIndexChanged(object sender, System.EventArgs e) { int personID = Convert.ToInt32(ddlParent.SelectedItem.Value); string query = "SELECT PhoneNumber,PhoneID FROM Phone WHERE PersonID = "+personID; SqlDataAdapter ad = new SqlDataAdapter(query,myConnection); DataSet ds = new DataSet(); ad.Fill(ds,"Phone"); ddlChild.DataSource = ds; ddlChild.DataTextField = "PhoneNumber"; ddlChild.DataValueField = "PhoneID"; ddlChild.DataBind(); }

I hope you like the article happy coding.