Textbox data Output - vb.net

Question

Good day im having some trouble with my code
Private Sub TextBox1_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox1.KeyDown
If e.KeyCode = Keys.Tab Then
checkoperator()
TextBox1.Text = ""
SendKeys.Send("{BACKSPACE}")
If lbloperatorb.Text = "" Then
TextBox1.Text = ""
MsgBox("User ID does not exist.")
lbloperatorb.Text = ""
TextBox1.Focus()
Else
TextBox1.Text = lbloperatorb.Text
TextBox1.Enabled = False
End If
cmbmodel1.Focus()
End If
End Sub
Public Sub checkoperator()
Dim cmd As New MySqlCommand
cmd.Connection = conn
cmd.CommandText = "SELECT empname FROM tbluser where userid= '" + TextBox1.Text + "'"
lbloperatorb.Text = cmd.ExecuteScalar
End Sub
When im using tab as my "ENTER" and pasting query at my text box here's what i got
i already tried to delete the textbox before sending data. but nothing happen

Answer 1

Instead of the KeyDown, use the Leave event. The following code will then work.
Private Sub TextBox1_Leave(sender As Object, e As EventArgs) Handles TextBox1.Leave
checkoperator()
'TextBox1.Text = ""
'SendKeys.Send("{BACKSPACE}")
If lbloperatorb.Text = "" Then
TextBox1.Text = ""
MsgBox("User ID does not exist.")
lbloperatorb.Text = ""
TextBox1.Focus()
Else
TextBox1.Text = lbloperatorb.Text
TextBox1.Enabled = False
lbloperatorb.Text = ""
End If
'lbloperatorb.Focus()
End Sub