To reproduce:
- Use the details view and add some columns.
- Hide the first column and export the data.
- The header row still contains the hidden column and the data is not exported.

Workaround:
Remove the first header cell manually:

private void Renderer_WorkbookCreated(object sender, WorkbookCreatedEventArgs e)
{
    var sheet = e.Workbook.Worksheets[0] as Worksheet;
    CellIndex range = new CellIndex(0, 0);
    CellSelection selection = sheet.Cells[range];


    selection.Remove(RemoveShiftType.Left);

}

Workaround: after rebinding the control invalidate its measure:
this.radCardView1.CardViewElement.InvalidateMeasure(true);

To reproduce:
private void RadListView1_CurrentItemChanging(object sender, Telerik.WinControls.UI.ListViewItemChangingEventArgs e)
{
    e.Cancel = true;
}

Workaround:

private void RadListView1_SelectedIndexChanged(object sender, EventArgs e)
{
    this.radListView1.SelectedIndexChanged -= RadListView1_SelectedIndexChanged;
    this.radListView1.SelectedIndex = 0;
    this.radListView1.SelectedIndexChanged += RadListView1_SelectedIndexChanged;
}

Use the attached project to reproduce.

Workaround:
 - Reset the descriptors after the changes are performed.

Dim sortDescriptor = radListView1.SortDescriptors(0)
radListView1.SortDescriptors.Clear
'add/remove items
radListView1.SortDescriptors.Add(sortDescriptor)

I got an exception when I'll try to add new items in a radcheckeddropdownlist.
No differences between AddRange(List<objects>) and Add(<object>)

We use the dropdownlist in the CustomAppointmentEditDialog for resources and here some sample code:
                //cmbResourceMulti.BeginUpdate();
        
                cmbResourceMulti.Items.Clear();
                var resources = data.GetRooms();

                List<RadCheckedListDataItem> lst = new List<RadCheckedListDataItem>();

                foreach (var res in resources)
                {
                    var item = new RadCheckedListDataItem(res.Raumname);
                    item.Tag = res;
                    item.Value = res.ID;
                    lst.Add(item);

                    if (sourceEvent.ResourceId != null && sourceEvent.ResourceIds.Contains(new EventId(res.ID)))
                    {
                        item.Checked = true;
                    }
                }
                
                cmbResourceMulti.Items.AddRange(lst.ToArray());
                //cmbResourceMulti.EndUpdate();
                cmbResourceMulti.Refresh();

On first load everything is working fine. Open an existing appointment and check a new resource. After saving the appointment and reopen it, the error appears .
See attached file.

Can you help please?
 

To reproduce use the attached project.

Workaround:
radCheckedDropDownList1.CheckedDropDownListElement.BeginUpdate();

radCheckedDropDownList1.CheckedMember = "Selected";
radCheckedDropDownList1.DisplayMember = "Name";         
radCheckedDropDownList1.DataSource = dataSource;

radCheckedDropDownList1.CheckedDropDownListElement.EndUpdate();

To reproduce: 
- Add some custom groups
- Change the default comparer and sort the items.

Workaround
Assign the custom comparer to each of the groups



 

It should be similar to RadCheckedListBox:

DataTable dt = new DataTable();
dt.Columns.Add("Id",typeof(int));
dt.Columns.Add("Name", typeof(string));
dt.Columns.Add("IsChecked", typeof(int));

for (int i = 0; i < 10; i++)
{
    dt.Rows.Add(i,"Item"+i,i%2);
}
this.radCheckedDropDownList1.DataSource = dt;
this.radCheckedDropDownList1.DisplayMember = "Name";
this.radCheckedDropDownList1.ValueMember = "Id";
this.radCheckedDropDownList1.CheckedMember = "IsChecked";

How to reproduce: Bind RadCardView to the Employees table from the Northwind database:
public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        this.radCardView1.CardViewItemCreating += radCardView1_CardViewItemCreating;
    }

    private void radCardView1_CardViewItemCreating(object sender, Telerik.WinControls.UI.CardViewItemCreatingEventArgs e)
    {
        CardViewGroupItem group = e.NewItem as CardViewGroupItem;
        if (group != null)
        {
            group.IsExpanded = false;
        }
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        this.employeesTableAdapter.Fill(this.nwindDataSet.Employees);
    }
}

Workaround: handle the CardViewItemFormatting event
private void radCardView1_CardViewItemFormatting(object sender, CardViewItemFormattingEventArgs e)
{
    CardViewGroupItem group = e.Item as CardViewGroupItem;
    if (group != null && group.Tag == null && group.Parent != null && group.Parent.Parent != null && group.Parent.Parent is CardListViewVisualItem)
    {
        group.IsExpanded = false;
        group.Tag = "Processed";
    }
}

To reproduce:
- Use the mouse to select an item from the drop down list.
- Using the keyboard, type a letter  and use the mouse to select one more item.
- Change the DataSource with a button.

Workaround:
radCheckedDropDownList1.DataSource = null;
radCheckedDropDownList1.AutoCompleteMode = AutoCompleteMode.None;

radCheckedDropDownList1.ValueMember = "Id";
radCheckedDropDownList1.DisplayMember = "Value";
radCheckedDropDownList1.CheckedMember = "IsSelected";
radCheckedDropDownList1.DataSource = list;

radCheckedDropDownList1.AutoCompleteMode = AutoCompleteMode.Suggest;

To reproduce:
public RadForm1()
{
    InitializeComponent();
    radListView1.EnableCustomGrouping = true;
    radListView1.EnableFiltering = true;
    radListView1.FilterPredicate = Filter;

    radListView1.ShowGroups = true;
    ListViewDataItemGroup docGroup = new ListViewDataItemGroup("Documents");
    ListViewDataItemGroup diskGroup = new ListViewDataItemGroup("Disks");

    radListView1.Groups.Add(docGroup);
    radListView1.Groups.Add(diskGroup);

    for (int i = 0; i < 100; i++)
    {
        ListViewDataItem item = new ListViewDataItem("g1");
        item.Group = docGroup;
        item.Value = rnd.Next(100);
        this.radListView1.Items.Add(item);

        item = new ListViewDataItem("g2");
        item.Group = diskGroup;
        item.Value = rnd.Next(100);
        this.radListView1.Items.Add(item);
    }
}

private void radButton1_Click(object sender, EventArgs e)
{
    radListView1.FilterDescriptors.Add("Value", Telerik.WinControls.Data.FilterOperator.IsGreaterThan, 50);
}
bool Filter(ListViewDataItem item)
{
    Console.WriteLine(item.Value);
    int value = 0;
    if ((int.TryParse(item.Value.ToString(), out value)))
    {

        return value < 50;
    }
    return true;
}

Workaround:
ListViewGroupedItemsCollection items = docGroup.Items as ListViewGroupedItemsCollection;
var innerList = items.GetType().GetProperty("InnerList", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Instance).GetValue(items);
var view = ((RadListSource<ListViewDataItem>) innerList).CollectionView;
view.Filter = Filter;

The user won't be allowed to enter some text if a match doesn't exist.

To reproduce:
- Open the attached project.
- Press the button and then select an item, perform the same operation 2 times. 

Workaround:
The workaround is available in the attached project as well.

To reproduce:

List<string> items = new List<string>();
for (int i = 0; i < 5; i++)
{
    items.Add("Item"+i);
}
this.radCheckedDropDownList1.Items.AddRange(items);

Workaround: add a range of RadCheckedListDataItems

To reproduce: 
1. Drag and drop RadListView and set the ViewType to DetailsView
2. Add few rows and 2 columns. Set the font of items to Trebuchet MS
3. While resizing columns, the text jumped up. 

Workaround: 
Set the AllowArbitraryItemHeight property to true: 
this.radListView1.AllowArbitraryItemHeight = true;

To reproduce:
- Initialize the control like this:
public Form1()
{
    InitializeComponent();
    this.radListView1.ListViewElement.Children[0].Children[0].Padding = new Padding(0, 0, 50, 0);
    this.radListView1.ListViewElement.BackColor = Color.FromArgb(255, 2, 48, 108);
    this.radListView1.ItemSpacing = 10;
    this.radListView1.ItemSize = new Size(152, 152);
    this.radListView1.AllowArbitraryItemHeight = false;
    this.radListView1.AllowArbitraryItemWidth = false;
}

private void Form1_Load(object sender, EventArgs e)
{
    for (int i = 1; i < 23; i++)
    {
        ListViewDataItem item = new ListViewDataItem();
        item.Text = "The7quick7brown7fox7jumps7over7the7lazy7dog";
        item.NumberOfColors = 1;
        item.BackColor = Color.FromArgb(255, 106, 90, 167);
        item.ForeColor = Color.White;

        this.radListView1.Items.Add(item);
    }
}

- Resize the form in such way that there is a free space on the right side of the items.
- Maximize and then restore the form.
- The space is gone.

FIX. RadListView - one should be able to style (via theme and cell formatting) the header area besides the header cells

Please refer to the attached screenshot.

To reproduce:

public RadForm1()
{
    InitializeComponent();
    
    Font f = new Font("Microsoft Sans Serif", 9.5f);
    this.radDropDownList1.DropDownStyle = Telerik.WinControls.RadDropDownStyle.DropDownList;
    this.radDropDownList1.Font = f;

    this.radDropDownList2.DropDownStyle = Telerik.WinControls.RadDropDownStyle.DropDown;
    this.radDropDownList2.Font = f;
}

Workaround:  If the text is not completely visible in RadDropDownList for a specific font you can increase the minimum height of the RadDropDownList and the DropDownListElement.TextBox.TextBoxItem.TextBoxControl.

public RadForm1()
{
    InitializeComponent();
    this.radDropDownList1.MinimumSize = new Size(0, 25);
    this.radDropDownList1.DropDownListElement.TextBox.TextBoxItem.TextBoxControl.MinimumSize = new Size(0, 25);
}

How to reproduce: 

public Form1()
{
    InitializeComponent();

    new RadControlSpyForm().Show();

    for (int i = 0; i < 2; i++)
    {
        this.radCheckedDropDownList1.Items.Add("Item &" + i);
    }

    this.radCheckedDropDownList1.VisualListItemFormatting += radCheckedDropDownList1_VisualListItemFormatting;
}



Workaround:

private void radCheckedDropDownList1_VisualListItemFormatting(object sender, VisualItemFormattingEventArgs args)
{
    RadCheckedListVisualItem item = args.VisualItem as RadCheckedListVisualItem;
    RadLabelElement lbl = item.FindDescendant<RadLabelElement>();
    lbl.UseMnemonic = false;
}

To reproduce: 
1. Add RadListView with few items 
2. Set the ShowCheckBoxes property to true and the Dock property to Fill
3. Subscribe to the VisualItemFormatting event and use the following code: 
void radListView1_VisualItemFormatting(object sender, ListViewVisualItemEventArgs e)
{
    IconListViewVisualItem item = e.VisualItem as IconListViewVisualItem;
    if (item != null)
    {
        ListViewItemCheckbox checkBox = item.ToggleElement as ListViewItemCheckbox;
        if (item.Text.Contains("coffee") || item.Text.Contains("Americano"))
        {
            checkBox.Visibility = Telerik.WinControls.ElementVisibility.Hidden;
        }
    }
}
4. Run the form.The checkboxes are hidden until resizing the form. 


Workaround: 
Set the MaxSize of checkboxes: 
void radListView1_VisualItemFormatting(object sender, ListViewVisualItemEventArgs e)
{
    IconListViewVisualItem item = e.VisualItem as IconListViewVisualItem;
    if (item != null)
    {
        ListViewItemCheckbox checkBox = item.ToggleElement as ListViewItemCheckbox;
        if (item.Text.Contains("coffee") || item.Text.Contains("Americano"))
        {
            checkBox.MaxSize = checkBox.MaxSize = new Size(1,1);
        }
    }
}