You have an error in your SQL syntax;
check the manual that corresponds to your MySQL server version for the right syntax to use near ')' at line 1;
What's wrong with this bracket
private void BindGrid()
{
MySqlConnection con = new MySqlConnection(constr);
MySqlCommand cmd = new MySqlCommand("SELECT Rasm FROM rasmlar where Rasm_ID IN (" + String.Join(",", getRasm_ID1()) + ")", con);
MySqlDataAdapter da = new MySqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
gvImages.DataSource = dt;
gvImages.DataBind();
}