Response.Redirect causes IsPostBack to be true

Question

I have a button on an ASP.Net page that will call Response.Redirect back to the same page after performing some processing in order to re-display the results of a query. However, for some reason, the page comes up blank. It seems that IsPostBack is returning true after the redirect. Anybody know why this would happen?

The page is a custom page in Community Server. Here is the basic code:

void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        string connStr = ConfigurationManager.ConnectionStrings["SiteSqlServer"].ConnectionString;
        SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM ge_vw_NonResidents", connStr);
        DataTable tbl = new DataTable();
        da.Fill(tbl);
        da.Dispose();
        rptNonResidents.DataSource = tbl;
        rptNonResidents.DataBind();
    }
}

void btnApprove_Command(object sender, CommandEventArgs e)
{
    // Code removed for testing.

    Response.Clear();
    Response.Redirect("ApproveResidents.aspx", true);
    Response.End();
}

Answer 1

A Response.Redirect will trigger an HTTP GET from the browser. As no data is posted, IsPostBack is false. You have something else going on.

I'd suggest firing up Fiddler and looking at the sequence of requests. It should look something like:

• Client: HTTP POST (button click)
• Server: HTTP 302 (Redirect)
• Client: HTTP GET
• Server: HTTP 200 (Writes page)

Answer 2

I suggest this as a better solution to your problem than attempting to redirect from the browser.

protected void Page_Load( object sender, EventArgs e )
{
   if (!IsPosBack) {
      BuildData();
   }
}

void btnApprove_Command(object sender, CommandEventArgs e)
{
    // do your stuff and clear any some controls, maybe

    BuildData();
}

private void BuildData()
{
   string connStr = ConfigurationManager.ConnectionStrings["SiteSqlServer"].ConnectionString;
   SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM ge_vw_NonResidents", connStr);
   DataTable tbl = new DataTable();
   da.Fill(tbl);
   da.Dispose();
   rptNonResidents.DataSource = tbl;
   rptNonResidents.DataBind();
}