Koding input harga di Textbox ada keterangan Rupiah (Rp)

Koding input harga di Textbox ada keterangan Rupiah
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aduh gmn ya njelasinnya, jadi gini : ketika textbox harga diinputkan, langsung ada tulisan "Rp" nya, Lihat aja nih gambarnya yak...

nah coba nih temen2 pake ini di kodingnya? dimana? iya bener di TextboxHarga.Text nya, nah event nya apa hayooo?
iyappp keren banget... event nya "Changed"
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Private Sub Tharga_TextChanged(sender As Object, e As EventArgs) Handles Tharga.TextChanged
        Dim a As Long
        If Tharga.Text = "" Or Not IsNumeric(Tharga.Text) Then
            Exit Sub
        End If
        a = Tharga.Text
        Tharga.Text = Format(a, "Rp,##,##0")
        Tharga.SelectionStart = Len(Tharga.Text)
    End Sub
End Class
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