Question

How can i change system culture that affects all pages(programmatically)?
i saw this thread.

but i want to change culture in my Login page with this codes.

protected void btnChangeLanguage(object sender, EventArgs e)
{
    Thread.CurrentThread.CurrentCulture = new CultureInfo("es");
    Thread.CurrentThread.CurrentUICulture = new CultureInfo("es");
}

Thread.CurrentThread.CurrentUICulture = new CultureInfo("fa-IR")
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture("fa-IR")

My Culture Changed by top Code.
I checked by this code.

MsgBox("Current Culture is " + CultureInfo.CurrentCulture.EnglishName)

but still our text and labels are english. (i have english resource and persian resource.)

Answer 1

For a list of all cultures, see the documentation for the CultureInfo class

Regarding your other question, you can save a cookie with the language code as its value, and read it in the overriden InitializeCulture as follows:

Set the cookie with the language code as its value as soon as the user clicks the button:

protected void btnChangeLanguage_Click(object sender, EventArgs e)
{
    Response.Cookies.Add(new HttpCookie("language") { 
        Value="es",
        Expires=DateTime.Now.AddDays(30) /* A sample timestamp */
    });
}

(Little side note: I’ve appended a _Click to the handler’s name, since it may cause a conflict with the button’s name in the definition)

Read the cookie as soon as the InitializeCulture method is invoked during the early stages of the page’s lifecycle:

protected override void InitializeCulture()
{
    var cookie = Request.Cookies["language"];
    if (cookie != null)
    {
        Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cookie.Value);
        Thread.CurrentThread.CurrentUICulture = new CultureInfo(cookie.Value);
    }
    base.InitializeCulture();
}