如何在不可设置的控件中覆盖wndProc

Question

I have a XtraGrid and some columns can get masked depending on the value of another column.
I managed to achieve it by seting the mask in the editor in the CustomRowCellEdit event.

Snipet below:

private void myGridView_CustomRowCellEdit(object sender, CustomRowCellEditEventArgs e)
{
    if (e.Column.FieldName == "MyTargetField")
    {
        GridView gv = sender as GridView;
        var typeValue = gv.GetRowCellValue(e.RowHandle, gv.Columns["MaskOrNotDependsOnThisField"]);

        if (typeValue == DynamicMask)
        {

            var maskToApply = GetMaskForThisValue(gv.GetRowCellValue(e.RowHandle, gv.Columns["MyTargetField"]));

            RepositoryItemTextEdit riMaskedTextEdit = new RepositoryItemTextEdit();
            riMaskedTextEdit.Mask.MaskType = MaskType.Simple;
            riMaskedTextEdit.Mask.UseMaskAsDisplayFormat = true;
            riMaskedTextEdit.Mask.SaveLiteral = false;
            riMaskedTextEdit.Mask.EditMask = maskToApply;
            e.RepositoryItem = riMaskedTextEdit;
            //riMaskedTextEdit.KeyDown += EditorKeyDownDinamicMask;
        }
    }
}

It worked like a charm but some masks can be dynamic (hey I don't make the requeriments!).
So I uncomment that event handler line and created a KeyDownEventHandler .

Let's say my mask changes as user keeps typing like:

999.999 for 6 digits

999.999-9 for 7 digits

999.(999)/99 for 8 digits

Note I need to use KeyDown because the mask can prevent the ValueChanged event to fire.
I handled the keydown and managed to put this thing to work fine.

Question is: How to handle Paste events? (from both keyboard and mouse paste events)

I know how to override wndProc in a control, I already did it a few times before.
Problem here is RepositoryItemTextEdit class is not a control with a wndProc to override.
I digged a bit and found the above class has a

public TextEdit OwnerEdit { get; }

And that is the real guy handling the events.
Unfortunately devxpress left it as a non settable member.

Right now user cannot replace the 999.999 value with a 999.999-9 in copy paste because the mask truncates the pasted value.
Note it also prevents the ValueChaged event to fire

Answer 1

RepositoryItemTextEdit class is used to hold the properties for in-place instance of TextEdit class. Technically TextEdit class is box which holds the instance of TextBoxMaskBox class. TextBoxMaskBox class is inherited from System.Windows.Forms.TextBox class.
So, you can create your own RepositoryItemTextEdit , TextEdit and TextBoxMaskBox descendants and override WndProc method in your own TextBoxMaskBox descendant.
Here is example:

[UserRepositoryItem("RegisterPasteHandlerEdit")]
public class RepositoryItemPasteHandlerEdit : RepositoryItemTextEdit
{
    static RepositoryItemPasteHandlerEdit()
    {
        RegisterPasteHandlerEdit();
    }

    static private readonly object EventPaste;

    public const string CustomEditName = "PasteHandlerEdit";

    public RepositoryItemPasteHandlerEdit() { }

    public override string EditorTypeName => CustomEditName;

    public static void RegisterPasteHandlerEdit()
    {
        Image img = null;
        EditorRegistrationInfo.Default.Editors.Add(new EditorClassInfo(CustomEditName, typeof(PasteHandlerEdit), typeof(RepositoryItemPasteHandlerEdit), typeof(TextEditViewInfo), new TextEditPainter(), true, img));
    }

    public override void Assign(RepositoryItem item)
    {
        BeginUpdate();
        try
        {
            base.Assign(item);
            var source = item as RepositoryItemPasteHandlerEdit;
            if (source == null) return;

            Events.AddHandler(EventPaste, source.Events[EventPaste]);
        }
        finally
        {
            EndUpdate();
        }
    }

    public event PasteEventHandler OnPaste
    {
        add
        {
            Events.AddHandler(EventPaste, value);
        }
        remove
        {
            Events.RemoveHandler(EventPaste, value);
        }
    }

    protected internal void RaiseOnPaste(PasteEventArgs e)
    {
        if (IsLockEvents)
            return;

        var handler = (PasteEventHandler)Events[EventPaste];
        handler?.Invoke(GetEventSender(), e);
    }
}

[ToolboxItem(true)]
public class PasteHandlerEdit : TextEdit
{
    static PasteHandlerEdit()
    {
        RepositoryItemPasteHandlerEdit.RegisterPasteHandlerEdit();
    }

    public PasteHandlerEdit() { }

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
    public new RepositoryItemPasteHandlerEdit Properties => base.Properties as RepositoryItemPasteHandlerEdit;

    public override string EditorTypeName => RepositoryItemPasteHandlerEdit.CustomEditName;

    protected override TextBoxMaskBox CreateMaskBoxInstance() => new PasteHandlerMaskBox(this);

    protected override void CreateMaskBox()
    {
        base.CreateMaskBox();

        var pasteHandlerMaskBox = MaskBox as PasteHandlerMaskBox;
        pasteHandlerMaskBox.OnPaste += PasteHandlerMaskBox_OnPaste;
    }

    private void PasteHandlerMaskBox_OnPaste(object sender, PasteEventArgs e) => Properties.RaiseOnPaste(e);
}

public class PasteHandlerMaskBox : TextBoxMaskBox
{
    private const int WM_PASTE = 0x0302;

    public PasteHandlerMaskBox(TextEdit ownerEdit) : base(ownerEdit) { }

    public event PasteEventHandler OnPaste;

    protected override void WndProc(ref Message msg)
    {
        if (msg.Msg == WM_PASTE)
        {
            var e = new PasteEventArgs();

            OnPaste?.Invoke(this, e);

            if (e.Cancel)
                return;
        }

        base.WndProc(ref msg);
    }
}

public class PasteEventArgs : CancelEventArgs
{
    public PasteEventArgs() { }
    public PasteEventArgs(bool cancel) : base(cancel) { }

    public string Text => Clipboard.GetText();
}

public delegate void PasteEventHandler(object sender, PasteEventArgs e);

In this example the OnPaste event is added to RepositoryItemPasteHandlerEdit class. You can use this:

private void repositoryItemPasteHandlerEdit1_OnPaste(object sender, PasteEventArgs e)
{
    MessageBox.Show(e.Text);

    if (...) // Perform some checks.
        e.Cancel = true;
}