ListBox Refresh DataSource?

[high6]

I want to refresh my list because right now I have a custom List with a sub List and I want to have each sub list entry as a separate line.

class WDFFileList : List<WDFFile>, System.ComponentModel.IListSource
{
    public bool ContainsListCollection
    {
        get
        {
            return true;
        }
    }
    public System.Collections.IList GetList()
    {
        List<WDFEntry> entries = new List<WDFEntry>();
        foreach (WDFFile f in this)
        {
            foreach (WDFEntry e in f.Entries)
            {
                entries.Add(e);
            }
        }
        return entries;
    }
}

Now this "works" as in when I first set the databind GetList() is called. But how do I refresh the datasource? Like when I add some entries I want to update the listbox.

I have tried

UsageList.DataSource = null;
            UsageList.DataSource = Files;

But GetList() wasn't called.

Just tried this

class WDFFileList : List<WDFFile>, System.ComponentModel.IListSource
{
    public List<WDFEntry> Entries = new List<WDFEntry>();

    public void Refresh()
    {
        Entries.Clear();
        foreach (WDFFile f in this)
        {
            foreach (WDFEntry e in f.Entries)
            {
                Entries.Add(e);
            }
        }
    }

    public bool ContainsListCollection
    {
        get
        {
            return true;
        }
    }
    public System.Collections.IList GetList()
    {
        return Entries;
    }
}

Still didn't update.


How do you update a custom datasource? Or am I approaching this wrong?

[jmcilhinney]

You should inherit BindingList instead of List and then you can call ResetBindings, although I've never tried it with a custom IListSource. The problem I see is that your class is an IList AND and IListSource, which may be causing its IListSource nature to be ignored and its IList nature used. Generally a class won't implement both. To avoid this potential conflict you might want to hide your List inside rather than inheriting, so that you class will only implement IListSource.

[high6]

You should inherit BindingList instead of List and then you can call ResetBindings, although I've never tried it with a custom IListSource. The problem I see is that your class is an IList AND and IListSource, which may be causing its IListSource nature to be ignored and its IList nature used. Generally a class won't implement both. To avoid this potential conflict you might want to hide your List inside rather than inheriting, so that you class will only implement IListSource.

I will try BindingList.

I tried that, it gave the same result. GetList() was only called once when I set the DataSource.

[jmcilhinney]

So try the rest of my advice. Implementing IList and IListSource in the same class is asking for trouble because an IListSource is supposed to be the source of a list, not a list itself.

[high6]

So try the rest of my advice. Implementing IList and IListSource in the same class is asking for trouble because an IListSource is supposed to be the source of a list, not a list itself.

But with BindingSource can you give the ListBox a custom list?

[high6]

class WDFEntryList : System.ComponentModel.BindingList<WDFEntry>
{
}

class WDFFileList : List<WDFFile>
{
    public WDFEntryList Entries = new WDFEntryList();

    public void Refresh()
    {
        Entries.Clear();
        foreach (WDFFile f in this)
        {
            foreach (WDFEntry e in f.Entries)
            {
                Entries.Add(e);
            }
        }
    }

}

It "works" but it takes an awful long time to load because I think it is rendering each time it adds an item. Is there a way to pause the rendering?

[high6]

Okay well this works and doesn't take 10-20 seconds to load.

class WDFEntryList : List<WDFEntry>, System.ComponentModel.IListSource
{
    public bool ContainsListCollection
    {
        get { return true; }
    }
    public System.Collections.IList GetList()
    {
        return this;
    }
}

class WDFFileList : List<WDFFile>
{
    public WDFEntryList Entries = new WDFEntryList();

    public void Refresh()
    {
        Entries.Clear();
        foreach (WDFFile f in this)
        {
            foreach (WDFEntry e in f.Entries)
            {
                Entries.Add(e);
            }
        }
    }

}

            UsageList.DataSource = null;
            
            Files.Refresh();

            UsageList.DataSource = Files.Entries;