How to check internet connection before form loads?

Question

I have a method that requires internet connection to function, How can I check for internet connection before my form loads? I would like to display an error message box if there is no connection and NOT load to form.

Here's my attempt:

private void Form1_Load(object sender, EventArgs e)
    {

        bool checkConnection = NetworkInterface.GetIsNetworkAvailable();
        if (checkConnection = false)
        {
            MessageBox.Show("error no con.");
        }

Look into [Control.HandleCreated Event](https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.control.handlecreated?view=netframework-4.7.2) — Trevor, Apr 16 '19 at 15:36
Possible duplicate of [What is the best way to check for Internet connectivity using .NET?](https://stackoverflow.com/questions/2031824/what-is-the-best-way-to-check-for-internet-connectivity-using-net) — Liam, Apr 16 '19 at 15:39
Possible duplicate of [Cancel form load](https://stackoverflow.com/questions/11148671/cancel-form-load) — Broots Waymb, Apr 16 '19 at 15:41
@Liam, that code will get executed before form load or You can write the same in Program.cs file of your project — Vikas Gupta, Apr 16 '19 at 15:41

score 0 · Answer 1 · answered Apr 16 '19 at 15:45

Looking at your code

if (checkConnection = false)
{
     MessageBox.Show("error no con.");
}

Notice

if (checkConnection = false)

it's = Not ==

so you should change it and make

if (!checkConnection)

And FYI NetworkInterface.GetIsNetworkAvailable();

is not an efficient way of checking for internet connection.

Please refer this for checking internet connectivity

How to check internet connection before form loads?

1 Answers1