Topic: State - Query Strings
Query Strings
Use these strings to pass information between requests and responses as part of the Web Address.
Query strings are visible to the user, so they should not contain secure information such as passwords
Query Strings allow you to send additional information along with an address. In HTML, query
strings appear after a question mark in a hyperlink, as shown here:
<A HREF="WebForm1.aspx?UName=Wombat">Query String sample.</A>
To send a query string in code, add it to the address of a Redirect method. The following
Click event procedure is equevalent to the preceding HTML:
private void butSend_Click(object sender, System.EventArgs e)
{
// redisplay this page with a QueryString
Response.Redirect(Request.FilePath + "?UName=Wombat");
}
To retrieve a query string in code, use the QueryString method of the Request object.
The following code displays the UName item from the query string created in the
preceeding examples.
private void Page_Load(object sender, System.EventArgs e)
{
// Check for QueryString
if (Request.QueryString["Uname"] != null)
{
//Display message
lblQstring.Text = "QueryString UName=";
// Display QueryString
lblQstring.Text += Request.QueryString["UName"];
}
}