ObjectListView exception exception (for impact testing)

Question

I am using a Grammarian ObjectListView. I changed my old lists to this, but all I do is fill in the elements. But when the application starts and my mouse is above the list, it immediately throws an exception for:

System.InvalidCastException was unhandled
  Message="Unable to cast object of type 'System.Windows.Forms.ListViewItem' to type 'BrightIdeasSoftware.OLVListItem'."
  Source="ObjectListView"

How to fix it?

I also use Win7 if this is important.

EDIT:

I use a dictionary. It looks like I need to use the SetObjects method instead of adding elements.

Ok, that's great, but I'm just using the dict.Value collection. I do not want to change the data through listview, only show. So I have only 1 column and a list of all that are rows. Is it possible?

I would appreciate a small sample.

Answer 1

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Answer 2

- SetObjects() ListViewItems. ObjectListView ListViewItems. , ListViewItems.

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Answer 3

OP:

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        // Create dictionary.. Can be done somewhere else..
        var dictionary = new Dictionary<int, string>();
        dictionary.Add(1, "Item 1");
        dictionary.Add(2, "Item 2");

        // You can set up the column in the designer as well.
        objectListView1.Columns.Add(new OLVColumn(title: "Items", aspect: "Value"));
        // Initially tells OLV to use the dictionary as a datasource.
        objectListView1.SetObjects(dictionary);

        // .....


        // Later on, you can add another item to the dictionary.
        dictionary.Add(3, "Item 3");
        // All you have to do now, is call .BuildList(), and your listview is updated.
        // shouldPreserveState can be false if you want. I want it to be true. :)
        objectListView1.BuildList(shouldPreserveState:true);

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---

@ElektroStudios

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"", write a 1000 lines model class... Just to add 1 string to a ListView. . .

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        // Items collection.
        // Add your list view items to this.
        // Note the fact that we have a different amount of subitems!!!
        var items = new List<ListViewItem>
        {
            new ListViewItem(new []{"Hello", "Stack","Overflow"}), 
            new ListViewItem(new []{"ObjectListView is pretty damn neat!"}), 
            new ListViewItem(new []{"Pretty", "Cool"})
        };

        // These are set up by the WinForms Designer when I create OLV columns in the designer.

        // Here, I am telling each column to use a custom getter, created by the SubItemGetter method.
        // ensures the sub-items actually exist on each LVI.
        olvColumn1.AspectGetter = SubItemGetter(0); // ListViewItem first sub-item is the same as ListViewItem.Text. :)
        olvColumn2.AspectGetter = SubItemGetter(1);
        olvColumn3.AspectGetter = SubItemGetter(2);

        // NOTE: I assume you know at design-time how many columns there are in your list view.
        // Set them up as I've done above, or, if you want to be fancy..
        for (int index = 0; index < objectListView1.Columns.Count; index++)
        {
            OLVColumn column = objectListView1.AllColumns[index];
            column.AspectGetter = SubItemGetter(index);
        }

        // Tells OLV to use the items collection.
        objectListView1.SetObjects(items);

        // Sometime later, probably somewhere else in the code...
        items.Add(new ListViewItem(new []{"I","Dont","Care","How","Many","SubItems","There","Is!"}));
        // Tell OLV to rebuild!
        objectListView1.BuildList(shouldPreserveState:true); // I'd like to preserve state, please :)
    }

    private AspectGetterDelegate SubItemGetter(int subItemIndex)
    {
        // This returns a method that gives OLV the string it needs to render each cell,
        // while also making sure the sub item exists.
        return rowObject =>
        {
            // Cast the row object to a ListViewItem. This should be safe.
            var lvi = (ListViewItem) rowObject;
            // Make sure the index is not out of range.
            if (lvi.SubItems.Count <= subItemIndex)
                return null;
            // Return what needs to be displayed!
            return lvi.SubItems[subItemIndex].Text;
        };
    }
}

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Answer 4

I got a similar error while trying to pass a normal ListView in virtual mode to ListViewPrinter in OLV 2.7

The error occurred here:
#if !WITHOUT_OBJECTLISTVIEW
        /// <summary>
        /// Get the nth item from the given listview, which is in virtual mode.
        /// </summary>
        /// <param name="lv">The ListView in virtual mode</param>
        /// <param name="n">index of item to get</param>
        /// <returns>the item</returns>
        override protected ListViewItem GetVirtualItem(ListView lv, int n)
        {
// Invalid Cast happens here
            return ((VirtualObjectListView)lv).MakeListViewItem(n);
        }

It works, as expected, using objectlistview. There is no solution other than using a list of objects.