Xamarin C＃MySql TypeinitializationException

Question

如何解决以下错误？

  

System.TypeinitializationException：MySql.Data.MySqlClient的类型初始值设定项引发了异常

MySqlConnection con = new MySqlConnection("Server=db4free.net;Port=3306;database=lesetjadb;User Id=medical;Password=medical1997;charset=uf8");

try 
{
    // MySqlconnetion con = new MySqlconnetion()
    if (con.State == ConnectionState.Closed) 
    {
        con.Open();
        MySqlCommand cmd = new MySqlCommand("INSERT INTO user(email_address,Contact_Number,FirstName,LastName) VALUES (@email_address,@Contact_Number,@FirstName,@LastName)", con);
        cmd.Parameters.AddWithValue("@email_address", email.Text);
        cmd.Parameters.AddWithValue("@Contact_Number", contact.Text);
        cmd.Parameters.AddWithValue("@FirstName", name.Text);
        cmd.Parameters.AddWithValue("@LastName", surname.Text);
        cmd.ExecuteNonQuery();
        sysLog.Text = "You have successfully registered";
    }
}
catch (MySqlException ex) 
{
    sysLog.Text = ex.ToString();
}    
finally 
{
    con.Close();
}