Question

I have a problem, that I can’t solve.
I am writing an application that will help to change system proxy easily. It has a listView with some items. These items have checkboxes.
Logic of application demands that only one item can be checked at a time, so I have following code to make sure it works well:

    private void listView1_ItemChecked(object sender, ItemCheckedEventArgs e)
    {
        listView1.ItemChecked -= listView1_ItemChecked;
        foreach(ListViewItem item in listView1.Items)
        {
            if(item != e.Item)
            {
                item.Checked = false;
            }
        }
        listView1.ItemChecked += listView1_ItemChecked;
    }

Also my application needs to check some value in registry on it’s start and compare it’s text with my items in listView.
I am doing it like that:

    private void GetProxyFromRegistry()
    {
        RegistryKey SystemProxy = Registry.CurrentUser.CreateSubKey(@"Software\Microsoft\Windows\CurrentVersion\Internet Settings");
        try
        {
            string UsedProxy = SystemProxy.GetValue("ProxyServer").ToString();
            foreach (ListViewItem item in listView1.Items)
            {
                if (UsedProxy == item.Text + ":" + item.SubItems[1].Text)
                {
                    item.Checked = true;
                }
                else
                {
                    item.Checked = false;
                }

            }
        }
        catch (Exception exc) 
        {
            MessageBox.Show(exc.Message);
        }
    }

The problem is that none of the listView1.Items will be checked except last one when used.
I know that it’s because of listView1_ItemChecked(), but I do not know how to solve it the other way.
Can you help me find a solution how to either uncheck all other checkboxes, or find a workaround to make correct item be checked?

Answer 1

So starting with your ItemCheck event, it should be like this:

void listView1_ItemCheck(object sender, ItemCheckEventArgs e)
{
        if (e.currentValue == CheckState.Checked)
            return;
        foreach (ListViewItem item in listView1.Items)
        {
            if (item.Index != e.Index)
            {
                item.Checked = false;
            }
        }
}

For the next issue, I’d suggest setting a breakpoint at this line of code here:

   if (UsedProxy == item.Text + ":" + item.SubItems[1].Text)

When the breakpoint is hit (on the last index), check to see what’s different about that item in comparison to the others (look at case sensitivity, for instance).