C#判斷網路連接狀態

DllImport("wininet.dll",EntryPoint="InternetGetConnectedState")]
public extern static bool InternetGetConnectedState(out int connectionDescription,int reservedValue);
//參數說明connectionDescription串連說明,reservedValue保留值

public bool IsConnectedToInternet()
{
    int Desc=0;
    return InternetGetConnectedState(out Desc,0);
}
判斷網路狀態的實現代碼如下:

private void button2_Click(object sender,EventArgs e)
{
    if(IsConnectedToInternet())
    {
        MessageBox.Show("已串連在網上!","提示");
    }
     else
        MessageBox.Show("未串連在網上!!","提示");
}