private void pictureBox1_Click(object sender, EventArgs e)
{
Wallpaper w = new Wallpaper();
string arkaplan = Environment.CurrentDirectory + "\\arkaplanlar\\Adsız.bmp";
textBox1.Text = arkaplan;
w.ArkaPlaniDegistir(textBox1.Text, Wallpaper.Pozisyon.Centered);
}