Alowdrop allows two times drop! Wpf VB.NET

<Window x:Name="TheMainWindow" x:Class="MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:SRT2Nuendo"
        mc:Ignorable="d"
        Title="MyDropTest"
        Height="500"
        Width="1000"
        WindowStartupLocation="CenterScreen"
        WindowStyle="None"
        AllowDrop="True"
        Drop="FileDrop">

    <TextBox x:Name="tbSaveCSV"
    HorizontalContentAlignment="Left"
    AllowDrop="True"
    Drop="FileDrop"/>
</Window>

Private Sub FileDrop(sender As Object, e As DragEventArgs)
        If (e.Data.GetDataPresent(DataFormats.FileDrop)) Then
            Dim DroppedItems As String() = e.Data.GetData(DataFormats.FileDrop)
            Dim TheFile As String = IO.Path.GetFullPath(DroppedItems(0))
            MsgBox (TheFile.Name)
        End If
    End Sub